Frequency stabilization of a terahertz quantum-cascade laser to the Lamb dip of a molecular absorption line.

We demonstrate the frequency stabilization of a terahertz quantum-cascade laser (QCL) to the Lamb dip of the absorption line of a D2O rotational transition at 3.3809309 THz. To assess the quality of the frequency stabilization, a Schottky diode harmonic mixer is used to generate a downconverted QCL signal by mixing the laser emission with a multiplied microwave reference signal. This downconverted signal is directly measured by a spectrum analyzer showing a full width at half maximum of 350 kHz, which is eventually limited by high-frequency noise beyond the bandwidth of the stabilization loop.

Clustering and variable selection in the presence of mixed variable types and missing data.

We consider the problem of model-based clustering in the presence of many correlated, mixed continuous, and discrete variables, some of which may have missing values. Discrete variables are treated with a latent continuous variable approach, and the Dirichlet process is used to construct a mixture model with an unknown number of components. Variable selection is also performed to identify the variables that are most influential for determining cluster membership. The work is motivated by the need to cluster patients thought to potentially have autism spectrum disorder on the basis of many cognitive and/or behavioral test scores. There are a modest number of patients (486) in the data set along with many (55) test score variables (many of which are discrete valued and/or missing). The goal of the work is to (1) cluster these patients into similar groups to help identify those with similar clinical presentation and (2) identify a sparse subset of tests that inform the clusters in order to eliminate unnecessary testing. The proposed approach compares very favorably with other methods via simulation of problems of this type. The results of the autism spectrum disorder analysis suggested 3 clusters to be most likely, while only 4 test scores had high (>0.5) posterior probability of being informative. This will result in much more efficient and informative testing. The need to cluster observations on the basis of many correlated, continuous/discrete variables with missing values is a common problem in the health sciences as well as in many other disciplines.

A randomized controlled trial of mindfulness-based stress reduction to prevent flare-up in patients with inactive ulcerative colitis.

BACKGROUND/AIMS: The primary therapeutic goals in ulcerative colitis (UC) are to maintain excellent quality of life (QOL) by treating flare-ups when they occur, and preventing flare-ups. Since stress can trigger UC flare-ups, we investigated the efficacy of mindfulness-based stress reduction (MBSR) to reduce flare-ups and improve QOL. METHODS: Patients with moderately severe UC, in remission, were randomized to MBSR or time/attention control. Primary outcome was disease status. Secondary outcomes were changes in markers of inflammation and disease activity, markers of stress and psychological assessments. RESULTS: 55 subjects were randomized. Absence of flares, time to flare and severity of flare over 1 year were similar between the two groups. However, post hoc analysis showed that MBSR decreased the proportion of participants with at least one flare-up among those with top tertile urinary cortisol and baseline perceived stress (30 vs. 70%; p < 0.001). MBSR patients who flared demonstrated significantly lower stress at the last visit compared to flared patients in the control group (p = 0.04). Furthermore, MBSR prevented a drop in the Inflammatory Bowel Disease Quality of Life Questionnaire during flare (p < 0.01). CONCLUSION: MBSR did not affect the rate or severity of flare-ups in UC patients in remission. However, MBSR might be effective for those with high stress reactivity (high perceived stress and urinary cortisol) during remission. MBSR appears to improve QOL in UC patients by minimizing the negative impact of flare-ups on QOL. Further studies are needed to identify a subset of patients for whom MBSR could alter disease course.

Evaluation of the ability of neurobiological, neurodevelopmental and socio-economic variables to predict cognitive outcome in premature infants.

BACKGROUND: When developed in the 1990s, the Neurobiologic Risk Score (NBRS) and Neurodevelopmental Risk Exam (NRE) correlated well with developmental outcomes in premature infants. Given recent advances in neonatology, we assessed their present ability to predict cognitive outcome, alone and combined with socio-economic factors. METHODS: One hundred and twenty-nine neonates <32 weeks gestational age were assessed at 6, 12 and/or 24 months corrected age with the Cognitive Adaptive Test/Clinical Linguistic and Auditory Milestone Scale (CAT/CLAMS). Indices of socio-economic status included maternal education and marital status. RESULTS: At 24 months corrected age (n= 67), the NBRS (r=-0.5), maternal education (r= 0.46) and marital status (r= 0.37) correlated with the CAT/CLAMS. These correlations increased when NBRS and maternal education were combined (r= 0.63) and when specific NBRS components (intraventricular haemorrhage, periventricular leukomalacia, seizures) and maternal education were combined (r= 0.66). CONCLUSIONS: In the contemporary neonatal intensive care unit, measures used to predict cognitive outcome should incorporate both neurobiological risk factors and socio-economic variables.

Efficient non-viral transfection of primary human adult chondrocytes in a high-throughput format.

OBJECTIVE: The development of a reliable high-throughput transfection protocol for primary human articular chondrocytes. METHODS: Primary human chondrocytes were isolated from adult knee cartilage by an optimized enzymatic digestion protocol and cultivated in high-density monolayer culture for 3-5 days. Isolated chondrocytes were transfected with a green fluorescent protein (GFP)-expressing reporter construct using amaxa's Nucleofector 96-well Shuttle System. Transfection efficiencies were measured by fluorescence activated cell sorting and cell viability was determined by an adenosine-5'-triphosphate (ATP) assay. siRNA oligonucleotides (against glyceraldehyde-3-phosphate dehydrogenase (GAPDH)) were transfected into the cells using the optimized nucleofection protocol and mRNA knockdown values were determined by a branched-DNA assay. RESULTS: Transfection efficiencies of more than 70% of surviving cells were achieved routinely with the nucleofection protocol presented in this article. Cell viability 24h post transfection was around 80%. The cell number used per transfection was reduced to 2x10(5) per sample. In addition, the protocol proved to be well suited for the transfer of siRNA molecules into primary human chondrocytes with suppression rates on the mRNA level of more than 95% (for GAPDH). CONCLUSIONS: We present the successful use of nucleofection on primary human chondrocytes using a microtiter plate compatible format that for the first time allows the efficient transfection of up to 96 samples in parallel. The optimized nucleofection protocol is offering maximum substrate flexibility by allowing transfer of DNA and siRNA oligonucleotides with the same set of parameters. Moreover, the transfection procedure requires substantially lower cell numbers than single cuvette protocols and is therefore perfectly suited for applications requiring multiple experimental replicates.

DNA methylation is not responsible for p21WAF1/CIP1 down-regulation in osteoarthritic chondrocytes.

OBJECTIVE: In this study, we were interested in the overall methylation level in aged and degenerated cartilage. Also, we looked at one gene which might be involved in the re-initiation of replicative activity in osteoarthritis (OA) chondrocytes, p21(WAF1/CIP1). p21(WAF1/CIP1) was previously suggested to be down-regulated in OA chondrocytes and is known to be regulated by epigenetic modulation. METHODS: Total methylation levels were analyzed by high pressure liquid chromatography (HPLC), mRNA expression of p21(WAF1/CIP1) and DNMT enzymes by real-time polymerase chain reaction. The methylation status of the p21(WAF1/CIP1)- promotor using bisulfite genomic sequencing was evaluated. RESULTS: General methylation analysis of genomic DNA showed no difference in between normal and aged/OA chondrocytes. Also no difference in methylation of the promotor of the p21(WAF1/CIP1) gene was detectable, which was significantly down-regulated in OA chondrocytes. DNMT1 and DNMT3a were expressed with no significant changes of expression levels found in OA chondrocytes. CONCLUSION: Cell cycle progression inhibitor p21(WAF1/CIP1) is expressed in normal and significantly down-regulated in OA articular chondrocytes, which may mediate the re-initiation of cell proliferation in OA cartilage. However, the suppression of p21(WAF1/CIP1) mRNA expression is not due to hypermethylation of its promotor. No overall changes in genome methylation levels were found in aged or OA cartilage. Interestingly, significant expression of DNA methyltransferases was found in articular chondrocytes, which supports that DNA methylation could still be a relevant mechanism of gene regulation in (osteoarthritic) chondrocytes, though not on an overall genomic level nor specifically for the regulation of the p21(WAF1/CIP1) gene.

Exanthema in Legionnaires' disease mimicking a severe cutaneous drug reaction.

Legionnaires' disease is an acute bacterial infection, generally caused by Legionella pneumophila, which primarily involves the lower respiratory tract, although it is often associated with multisystemic extrapulmonary features. Cutaneous features are very uncommon and may include erythematous or petechial, macular or maculopapular lesions. We report a male patient who expressed all features of a severe lobular pneumonia. Over the course of the disease the patient developed a livid erythematous, maculopapular exanthem rapidly extending over the entire body. Given the rapid development and target-like appearance of the skin lesions with extensive skin involvement and blister formation, the initial diagnosis was that of a severe cutaneous drug reaction. However, histological examination of biopsy did not confirm this diagnosis, but instead was suspicious for a viral exanthem or a more aggressive inflammatory response due to sensitization to bacterial antigens. L. pneumophila infection was verified during the course of the disease.

Epidemiology of diabetes mellitus in German general practitioners' consultation--results of the SESAM 2-study.

The treatment of chronic diseases is of eminent importance in primary care, and type 2-diabetes mellitus is one of the most common dysfunctions. Its world-wide prevalence has been increasing from year to year. Thus, to estimate the prevalence and incidence of diabetes mellitus, we performed the SESAM (Sächsiche epidemiologische Studie in der Allgemeinmedizin) 2-study in cooperation with general practitioners (GPs) from the German state of Saxony; 270 of the 2510 (10.8%) solicited physicians participated. Cross-sectional data were collected from 1 October 1999 until 30 September 2000, from randomly selected patients previously known to the practitioner. From a total of 8877 consultations with 270 GPs, diabetes was prevalent in 14% (n = 1241) of the patients and the incidence was 0.3% (27 of 8877 cases). The consultation prevalence was estimated at 14.3% (n = 1268; CI 13.6-15%). Of the diabetic patients, 3.5% (n = 44) suffered from type 1-diabetes, while type 2-diabetes was found in 66.9% (n = 848) of the cases. "Other diabetes" was determined in 19.2% (n = 244), and "not further specified diabetes", in 10.4% (n = 132) of the cases. Related to the German population in general, the prevalence ranged from 7.9 to 9.2%. The estimated consultation prevalence is about four times higher than that in other European countries. These data are of importance in illustrating the epidemiology of diabetes in the population and the direct repercussions for GPs. They also point out the significance of diabetes as a major challenge to the German health care system.

[Respiratory symptoms in the general practice. An analysis of the Leipzig SESAM Study]. / Atemwegsbeschwerden in der allgemeinärztlichen Sprechstunde. Eine Auswertung der Leipziger SESAM-Studie.

The Saxon Study of General Medicine (SESAM) investigated the reasons why patients consulted the general practitioner, which diagnoses were established and how the patients were subsequently treated. In the majority of cases, the respiratory symptoms were simple infections of the upper and lower respiratory tract. Pneumonia must always be considered, while severe pulmonary diseases are of no significance in the differential diagnosis of respiratory complaints in the general practice.

Long-term outcomes of children with symptomatic congenital cytomegalovirus disease.

OBJECTIVE: To assess long-term outcomes of children with symptomatic congenital cytomegalovirus (CMV) disease detected at birth. STUDY DESIGN: We used Cox regression to assess risk factors for intellectual disability (intelligence quotient <70), sensorineural hearing loss (SNHL; hearing level ⩾25 dB in any audiometric frequency) and vision impairment (best corrected visual acuity >20 or based on ophthalmologist report). RESULTS: Among 76 case-patients followed through median age of 13 (range: 0-27) years, 56 (74%) had SNHL, 31 (43%, n=72) had intellectual disability and 18 (27%, n=66) had vision impairment; 28 (43%, n=65) had intellectual disability and SNHL with/without vision impairment. Microcephaly was significantly associated with each of the three outcomes. Tissue destruction and dysplastic growth on head computed tomography scan at birth was significantly associated with intellectual disability and SNHL. CONCLUSION: Infants with symptomatic congenital CMV disease may develop moderate to severe impairments that were associated with presence of microcephaly and brain abnormalities.

A community randomized controlled clinical trial of mixed carotenoids and micronutrient supplementation of patients with acquired immunodeficiency syndrome.

OBJECTIVE: This clinical trial aims to evaluate if natural mixed carotenoids supplementation can improve the health and survival of acquired immunodeficiency syndrome (AIDS) patients. DESIGN: A placebo-controlled, prospective, randomized, double-blind, multicenter clinical trial. SETTING: Community, tertiary care human immunodeficiency virus (HIV) clinics of the Canadian HIV Trials Network (CTN). PARTICIPANTS: Three hundred and thirty-one adults with advanced AIDS on conventional management were recruited during routine clinic visits. INTERVENTIONS: All participants, including 166 controls, received daily oral specially formulated multivitamins including vitamin A and trace elements; 165 treatment group participants received additional daily oral natural mixed carotenoids, equivalent to 120,000 IU (72 mg) of beta-carotene daily. Follow-up was quarterly at routine clinic visits. RESULTS: Mean (s.d.) follow-up was for 13 (6) months. Thirty-six participants died by 18 months. Serum carotene concentration <1.0 micromol/l was present in 16% participants at baseline. Despite variation in carotene content of the treatment medication, serum carotene concentrations increased significantly to twice the baseline levels to 18 months follow-up in participants who received carotenoids treatment compared with controls (P < 0.0001). Although not statistically significant, mortality was increased in participants who did not receive carotenoids treatment compared with those who did (HR time to death 1.76, 95% CI 0.89, 3.47, P = 0.11). In multivariate analysis, survival was significantly and independently improved in those with higher baseline serum carotene concentrations (P = 0.04) or higher baseline CD4 T-lymphocyte counts (P = 0.005). Adjusted mortality was also significantly and independently increased in those who did not receive carotenoids treatment compared with those who did (HR time to death 3.15, 95% CI 1.10, 8.98, P = 0.03). CONCLUSIONS: Low serum carotene concentration is common in AIDS patients and predicts death. Supplementation with micronutrients and natural mixed carotenoids may improve survival by correction of a micronutrient deficiency. Further studies are needed to corroborate findings and elucidate mechanism of action.

[Presenting problem: abdominal pain]. / Vergessen Sie die Kolibris, denken Sie an das Wahrscheinlichste!

The Saxon Study for General Medicine (SESAM) investigated the reasons why patients consulted the general physician, what diagnoses were established, and how the patients were subsequently treated. In the majority of cases, the reason for the abdominal complaints was located in the gastrointestinal or urogenital tract, in the presence of infections or psychosomatic problems. Gynecological problems must also be considered, while diseases other than gastrointestinal are of no significance for the differential diagnosis of abdominal complaints in the general physician's office.

Circadian Rhythm and the Gut Microbiome.

Circadian rhythms are 24-h patterns regulating behavior, organs, and cells in living organisms. These rhythms align biological functions with regular and predictable environmental patterns to optimize function and health. Disruption of these rhythms can be detrimental resulting in metabolic syndrome, cancer, or cardiovascular disease, just to name a few. It is now becoming clear that the intestinal microbiome is also regulated by circadian rhythms via intrinsic circadian clocks as well as via the host organism. Microbiota rhythms are regulated by diet and time of feeding which can alter both microbial community structure and metabolic activity which can significantly impact host immune and metabolic function. In this review, we will cover how host circadian rhythms are generated and maintained, how host circadian rhythms can be disrupted, as well as the consequences of circadian rhythm disruption. We will further highlight the newly emerging literature indicating the importance of circadian rhythms of the intestinal microbiota.

[Insect stings and their sequelae]. / Bienen, Wespen, Hornissen. Kleiner Stich--grosse Wirkung.

In the summer months, insect stings are a common reason for seeking help from the general physician. In the majority of cases a local reaction is seen, but, far less often, an anaphylactic reaction may also occur. Such an acute situation requires calm but decisive action, and the initiation of an evaluation by an allergy specialist. The family doctor should regularly review the facilities for treating an anaphylactic reaction in his office, and, where necessary, optimize them.

Sex, drugs and HIV counseling and testing: a prospective study of behavior-change among methadone-maintenance clients in New England.

OBJECTIVES: To determine whether changes in injecting drug use and sexual behavior over a 12-month follow-up are associated with HIV counseling and testing (C and T) of injecting drug users in methadone maintenance treatment programs (MMTP) in Massachusetts and Connecticut. METHODS: Clients were invited to participate in a longitudinal study involving five interviews. Data were also obtained by ethnographers and from clinical records. Behavioral outcomes of interest were number of drug injections, sharing of unclean 'works' (injecting equipment), number of unprotected sex partners, and number of unprotected sexual episodes. Data analyses included multiple regression, odds ratios, and quantitative analysis of text-based data. RESULTS: Subjects reported reductions in both injecting drug use and sexual behavior Primary associations with reduced injecting drug use were remaining in the MMTP and attending HIV-positive support groups. A reduction in high-risk sexual behavior was associated with an HIV-positive test result and duration of HIV counseling in the MMTP. Increase in drug injecting use was associated with an HIV-positive test result. Inconsistent condom use was associated with enrollment in the MMTP where condoms were available only upon request and abstinence and monogamy between uninfected partners were promoted. CONCLUSIONS: Injecting drug users who self-select to participate in MMTP and HIV C and T, two public health HIV-prevention interventions, reduce their HIV-risk behaviors. Clients should be encouraged to remain in MMTP and HIV-infected clients should attend support groups for HIV-positive persons. MMTP staff should promote a variety of safer sex behaviors and provide condoms without request.

SCA17 caused by homozygous repeat expansion in TBP due to partial isodisomy 6.

An expanded polyglutamine domain in the TATA-binding protein (TBP) has been described in patients with spinocerebellar ataxia type 17 (SCA17) characterized by cerebellar ataxia associated with dementia. TBP is a general transcription initiation factor that regulates the expression of most eukaryotic genes transcribed by RNA polymerase II. SCA17, as an autosomal dominantly inherited progressive neurodegenerative disorder, is caused by heterozygous expansion of a CAG repeat coding for glutamine. Alleles with 27 to a maximum of 44 glutamine residues were found as the normal range, whereas expansions above 45 repeat units were considered pathological. Here, we present a patient with a very severe phenotype with a late onset but rapidly progressing ataxia associated with dementia and homozygous 47 glutamine residues caused by an apparent partial isodisomy 6. This extraordinary case has important implications for the insights of TBP and SCA17. The expanded polyglutamine domain in both TBP copies is not correlated with embryonic death indicating that the normal function of the protein is not disrupted by this kind of mutation but may account for the dementia seen in this patient.

Serum human chorionic gonadotropin clearance curves in patients with interstitial pregnancy treated with systemic methotrexate.

OBJECTIVE: To evaluate short-term effectiveness of systemic methotrexate (MTX) in interstitial pregnancy. DESIGN: Case series. SETTING: Two Dutch teaching hospitals. PATIENT(S): Eight consecutive patients with an unruptured interstitial pregnancy. INTERVENTION(S): Four doses of 1.0 mg/kg IM MTX alternated with 0.1 mg/kg oral folinic acid. Serum hCG concentrations were determined before the first MTX injection and followed until levels were undetectable. A second MTX course was started on day 14, if by then serum hCG concentrations were > 40% of the initial value. Serum hCG clearance curves of all patients in the present study were compared with those from our earlier studies, in which a different folinic acid regimen (15 mg orally) was used. MAIN OUTCOME MEASURE(S): Serum hCG clearance curves. RESULT(S): All patients were treated successfully: five with one course and three with two courses. Serum hCG clearance curves of these patients tended to decline more rapidly than those successfully treated with the 15 mg folinic acid regimen. CONCLUSION(S): Systemic MTX is an attractive therapeutic option in the conservative treatment of unruptured interstitial pregnancy. The regimen of four doses of 1.0 mg/kg IM MTX alternated with 0.1 mg/kg folinic acid is effective. Serum hCG clearance curves may serve as a guideline for monitoring MTX treatment, thus enabling a timely detection of impending treatment failure.

Across-fiber patterns may contain a sensory code for stimulus intensity.

Various models for sensory coding have used statistical approaches based on the assumption that the stimulus intensity parameter is represented in the afferent neurons as mean firing frequency. In this paper we question the assumption that this is the only code for intensity. We show that in lobster olfactory receptors narrowly tuned to hydroxyproline, an across-fiber pattern (AFP) code distinguished more concentration levels over a 5 log step range than a response magnitude code and, unlike the latter, was unaffected by response summation time. AFP discrimination of stimulus intensity appears to be based on high inter-cell response variability and low intra-cell response variability.