Multiple cytokines for the detection of Mycobacterium tuberculosis infection in children with tuberculosis

SETTING

Interferon-gamma (IFN-γ) release assays (IGRAs) play an important role in the diagnosis of Mycobacterium tuberculosis infection. However, in children with tuberculosis (TB), some studies have shown increased frequencies of false-negative or indeterminate IGRA results.

OBJECTIVE

To analyse the spectrum of different cytokines to improve the diagnostic accuracy of IGRAs in latent tuberculous infection (LTBI) and active TB.

DESIGN

We performed multiplex cytokine expression analysis of QuantiFERON® Gold In-Tube supernatants in children with active TB (n = 21) and disease-free contacts with (n = 15) and without LTBI (n = 12), to determine the sensitivity and specificity of the modified tests.

RESULTS

Of 21 initial cytokines analysed, IFN-γ and six other candidates (interleukin [IL] 2, inducible protein 10 [IP-10], IL-13, IL-1α, tumour necrosis factor alpha [TNF-α] and granulocyte-macrophage colony-stimulating factor [GM-CSF]) were significantly more elevated in children with TB and those with LTBI than in the non-infected controls. Sensitivity and specificity were similar for IFN-γ and IL-2, but lower for the remaining candidates. Notably, a subset of candidates, including IP-10, showed M. tuberculosis antigen-induced specific expression in non-infected children. None of the candidates showed differences in expression between children with TB and those with LTBI.

CONCLUSIONS

Our results did not suggest that alternative IGRA cytokines can distinguish between children with active TB and those with LTBI. IFN-γ and IL-2 showed comparable capacity in diagnosing M. tuberculosis infection in our study groups.

Eine Methode zur kombinierten Scatter- und Schwächungskorrektur ohne Transmissionsmessung für die Myokard-SPECT mit 99mTc- Verbindungen

Ziel: Für eine Doppelkopf-SPECT-Kamera wird eine Strategie zur Bestimmung der Schwächungsverteilung aus den Zählraten der Rückwärtsstreuung von 99mTc vorgestellt. Ziel war die Gewinnung von segmentierten und normierten Schwächungsbildern mit den Strukturen Lunge und Fett- bzw. Muskelgewebe, so daß nach dem Verfahren von Chang eine Schwächungskorrektur vorgenommen werden kann. Methoden: In den akquirierten Winkelprojektionen wurden sowohl Näherungen für die Schwächung als auch eine Scatterkorrektur nach dem Verfahren von Ogawa et al. berechnet, wobei die Akquisition simultan in drei getrennten 99mTc-Energiefenstern zur Ermittlung von Emissions- und Streustrahlung erfolgt. Anhand von Phantommessungen und Patientenmessungen wurde die Güte der Schwächungsnäherungen und der Schwächungskorrektur untersucht und die beste Wahl für alle auftretenden Parameter zur Schwächungskorrektur ermittelt. Ergebnisse: Das Verfahren stellt eine gute Näherung zur Korrektur der Photonenschwächung und der Streustrahlung dar. Eine Plausibilitäts-kontrolle an Phantom- und beispielhaften Patientenstudien belegte vorläufig auch die klinische Brauchbarkeit. Bei normaler Perfusion wurde die Verteilung homogenisiert, Defekte erschienen klarer. Probleme entstehen bei hohen Non-target-Aktivitäten, z. B. in der Gallenblase, und bei zu geringer Zählrate. Schlußfolgerung: Eine für die 99mTc MIBI-SPECT des Myokards sinnvolle und brauchbare Korrektur von Schwächung und Streuung ist auch ohne zusätzliche Transmissionseinrichtung möglich.

Bestimmung von Einflußgrößen für den Therapieerfolg der Radioiodtherapie bei Patienten mit Morbus Basedow

Ziel der Studie war es, zu prüfen, inwieweit der Erfolg einer Radioiodtherapie (RIT) des Morbus Basedow (MB) von verschiedenen Parametern (Schilddrüsenvolumen [SDVol], Funktion, TRAK, Thyreostase, Therapiedosis, 131l-Uptake, effektive Halbwertszeit) abhängt. Methode: Bei 78 Patienten mit gesichertem MB wurden 626 ± 251 MBq 131 lod oral zur Ablation der Schilddrüse appliziert. 3 Monate nach RIT wurden 60 Patienten kontrolliert. Ergebnisse: Bei Patienten mit einer Hyperthyreose oder TRAK <11 U/l zu Beginn der RIT wurden eine signifikant niedrigere Therapiedosis bzw. Halbwertszeit gefunden als bei nichthyperthyreoten Patienten bzw. Patienten mit TRAK ≤11 U/l. Patienten mit einem SDVol ≤25 ml zeigten signifikant niedrigere 131l-Uptakewerte unter Therapie, jedoch signifikant höhere Relativuptakewerte (131l- Uptake/SDVol) als solche mit SDVol <25 ml. Alle Therapieversager wurden während der RIT thyreostatisch behandelt, sie wiesen im Mittel signifikant niedrigere Therapiedosen und Relativuptakewerte sowie signifikant höhere SdVol als Therapieerfolge auf. Durch die RIT reduzierte sich das SDVol der Patienten um 44%, wobei Versager eine signifikant geringere Volumenreduktion aufwiesen. Patienten mit einer Therapiedosis ≤250 Gy zeigten signifikant schlechtere Therapieresultate als solche mit <250 Gy, nur ein Versager erreichte mehr als 250 Gy, während immerhin 50% der Versager <200 Gy (aber >250 Gy) erreichten. Die Anwendung multivariater Analysen (MANOVA und Faktorenanalysen) ergab die Thyreostase als den entscheidenden Negativfaktor für den Erfolg einer RIT. Schlußfolgerung: Aufgrund der gehäuften Therapieversager bei Patienten mit Thyreostase empfehlen wir daher für diese Patienten eine Erhöhung der Zieldosis auf 250 Gy.

Untersuchungen zum Einfluß von »Ecstasy« auf den zerebralen Glukosemetabolismus: eine 18-FDG-PET-Studie

Ziel: In der vorliegenden Studie sollte die Akutwirkung des »Ecstasy«- Analogons MDE (3,4-Methylendioxyethamphetamin) auf den zerebralen Glukosemetabolismus (rMRGIu) gesunder Probanden untersucht werden. Methode: In einer randomisierten Doppelblindstudie wurden 16 gesunde Probanden ohne Drogenanamnese mittels 18-FDG-PET 110-120 min nach oraler Verabreichung von 2 mg/kg KG MDE (n = 8) oder Plazebo (n = 8) untersucht. Zwei Minuten vor Injektion des Radio- pharmazeutikums startend erfolgte über insgesamt 32 min eine konstante kognitive Stimulation über ein Wortrepetitionsparadigma, um konstante und vergleichbare mentale Bedingungen während der zerebralen 18-FDG-Aufnahme zu gewährleisten. Die Darstellung der Indivi- dualanatomie erfolgte anhand T1-gewichteter 3D-flash MRT mit anschließender manueller Regionalisierung in 108 Regions-of-Interest und PET/MRT Overlay. Absolute Quantifizierung der rMRGIu sowie Normierung auf den Globalmetabolismus mit anschließendem Vergleich MDE versus Plazebo mittels U-Test nach Mann und Whitney. Ergebnisse: Gegenüber der Plazebo-Gruppe fand sich unter MIDE keine signifikante Änderung der globalen MRGIu (MDE: 41,8± 11,1 μmol/min/100 g, Placebo: 50,1 ± 18,1 μmol/min/100 g, p = 0,298). Die normierten metabolischen Daten zeigten eine signifikante Minderung der rMRGIu im beidseitigen Frontalkortex: links frontal posterior (-7,1%, p <0,05) und rechts präfrontal superior (-4,6 %, p <0,05). Signifikante Steigerungen der rMIRGIu fanden sich dagegen im beidseitigen Zerebellum (rechts: + 10,1%, p <0,01; links: +7,6 %, p <0,05) sowie im rechten Putamen (+6,2%, p <0,05). Schlußfolgerung: In der vorliegenden Studie konnten unter dem Akuteinfluß des »Ecstasy«-Analogons MDE neuro- metabolische Veränderungen im Sinne einer fronto-striato-cerebellären Dysbalance nachgewiesen werden, die Parallelen zu sowohl anderen psychotropen Substanzen als auch verschiedenen endogenen Psychosen aufweisen.

Altered Relationships Between rCBF in Different Brain Regions of Never-Treated Schizophrenics

Aim of this study was to investigate the relations between regiona cerebral blood flow (rCBF) of different brain regions in acute schizophrenia and following neuroleptic treatment.

Methods: Twenty-two never-treated, acute schizophrenic patients were examined with HMPAO brain SPECT and assessed psychopathological-ly, and reexamined following neuroleptic treatment (over 96.8 days) and psychopathological remission. rCBF was determined by region/cerebel-lar count quotients obtained from 98 irregular regions of interest (ROIs), summed up to 11 ROIs on each hemisphere. In acute schizophrenics, interregional rCBF correlations of each ROI to every other ROI were compared to the interregional correlations following neuroleptic treatment and to those of controls.

Results: All significant correlations of rCBF ratios of different brain regions were exclusively positive in controls and patients. In controls, all ROIs of one hemisphere except the mesial temporal ROI correlated significantly to its contralateral ROI. Each hemisphere showed significant frontal-temporal correlations, as well as cortical-subcortical and some cortico-limbic. In contrast, in acute schizophrenics nearly every ROI correlated significantly with every other ROI, without a grouping or relation of the rCBF of certain ROIs as in controls. After neuroleptic treatment and clinical improvement, this diffuse pattern of correlations remained.

Conclusions: These results indicate differences in the neuronal interplay between regions in schizophrenic and healthy subjects. In never-treated schizophrenics, diffuse interregional rCBF correlations can be seen as a sign of change and dysfunction of the systems regulating specificity and diversity of the neuronal functions. Neuroleptic therapy and psychopathologic remission showed no normalizing effect on interregional correlations.

Aus Erfahrung wird Wissen und Kompetenz

Erfahrungsexperten in die psychiatrische Arbeit einzubeziehen, ist mit der Idee verbunden, dass Krisenerfahrung und Bewältigungskompetenz neue wichtige Impulse bieten können, um das Verständnis psychischer Störungen und den Umgang mit Betroffenen zu erweitern und zu verbessern. In diesem Beitrag wird die Entwicklung und Erprobung der einjährigen Ausbildung für Psychiatrieerfahrene zum Genesungsbegleiter dargestellt. Diese Qualifikation wurde im europäischen Kontext entwickelt und von der EU gefördert. Sie ist die Basis der Peer-Arbeit an Institutionen und garantiert eine gute Verbindung von Reflexion und Authentizität.

Multivariate analysis of factors influencing the effect of radiosynovectomy

Objective: In this prospective study, the time to remission after Radiosynovectomy (RSV) was analyzed and the influence of age, sex, underlying disease, type of joint, and duration of illness on the success rate of RSV was determined. Methods: A total number of 57 patients with rheumatoid arthritis (n = 33) and arthrosis (n = 21) with a total number of 130 treated joints (36 knee, 66 small and 28 medium-size joints) were monitored using visual analogue scales (VAS) from one week before RSV up to four to six months after RSV. The patients had to answer 3 times daily for pain intensity of the treated joint. The time until remission was determined according to the Kaplan-Meier survivor-ship function. The influence of the prognosis parameters on outcome of RSV was determined by multivariate discriminant analysis. Results: After six months, the probability of pain relief of more than 20% amounted to 78% and was significantly dependent on the age of the patient (p = 0.02) and the duration of illness (p = 0.05), however not on sex (p = 0.17), underlying disease (p = 0.23), and type of joint (p = 0.69). Conclusion: Irrespective of sex, type of joint and underlying disease, a measurable pain relief can be achieved with RSV in 78% of the patients with synovitis, whereby effectiveness is decreasing with increasing age and progress of illness.

Isolierung eines neuen Lignans (Yangambin) und mögliche Korrelation zur Piperinführung

Aus Früchten von Piper guineense Schumach. et Thonn. (Proben aus dem Gebiete um Yangambi in der Republik Kongo und aus Nigeria wurde ein neues Lignan isoliert (0,2%), das Yangambin genannt und für das die Konstitution eines (+) -2.6-Bis- (2.3.4-trimethoxyphenyl) -3.7-dioxabicyclo - [3.3.0] -octan ermittelt wurde. Aus einem Vergleich der NMR-Spektren in Verbindung mit dem der optischen Drehwerte ergibt sich, daß Yangambin den gleichen sterischen Aufbau aufweist wie das ( + ) -Sesamin.

Die Lignanführung scheint korreliert zu sein mit dem Vorkommen des Scharfstoffes Piperin, der aus den Früchten in Ausbeuten von 0,33% isoliert wurde; Piperin-freie Früchte (Proben aus dem Nordosten der Republik Kongo und aus Urandi-Urundi) enthalten kein Yangambin, sondern ( + ) -Sesamin ( = Pseudocubebin) und Aschantin. Diese auffallende intraspezifische Variabilität chemischer Merkmale wird diskutiert im Hinblick auf Versuche anderer Autoren, die Art Piper guineense nach morphologischen Gesichtpunkten zu untergliedern.

Mice with heterozygous deficiency of manganese superoxide dismutase (SOD2) have a skin immune system with features of "inflamm-aging"

Dendritic cells (DC) are central in regulating skin immunity. Immunosenescence is associated with a chronic inflammatory state. Little is known about the contribution of DC to "inflamm-aging". When determining langerhans cell (LC) numbers, we found a 60 % reduction of LC in aged epidermis. Reactive oxygen species(ROS) are linked with aging. The mitochondrial manganese superoxide dismutase (SOD2) is in the first line of antioxidant defense. We investigated the function of DC from SOD2 heterozygous mice (SOD2+/-) and found that at 4 months of age LC numbers are not altered, but activated LC have impaired expression of MHC-II and CD44. Immature SOD2+/- DC produced increased proinflammatory IL-6 and chemokines CXCL1 and CXCL2. Upon challenge SOD2+/- DC accumulated ROS. When activating SOD2+/- DC by LPS they less efficiently upregulated MHC-II, CD86 and CD44. Surprisingly, in vivo contact hypersensitivity (CHS) was enhanced in SOD2+/- mice although SOD2+/- DC were less potent in stimulating wt T cells. However, SOD2+/- T cells showed increased proliferation, even when stimulated with SOD2+/- DC, possibly explaining the increased CHS. Our findings suggest that SOD2 is a molecular candidate in the regulation of "inflamm-aging" conveying both immunosuppressive and proinflammatory signals through alteration of DC and T cell functions.

Individual cow's milk allergens as prognostic markers for tolerance development?

BACKGROUND

Cow's milk allergy (CMA) is one of the most common causes of food allergy in the first years of life. Fortunately, the majority of children with CMA develop clinical tolerance with time. However, no good individual markers exist to predict whether this will occur. Therefore, a prognosis to identify children with persistent CMA at diagnosis would be helpful.

OBJECTIVE

In this study, we sought to assess whether measurement of IgE to individual allergens of cow's milk (CM) would separate patients with persistent CMA from those who became clinically tolerant to CM over time.

METHODS

A total of 52 patients ranging from 3 months to 114 months of age with proven CMA by DBPCFC were followed over time. From these 52 patients, 32 (61.5%) patients became tolerant in the analysed time period. All patients were rechallenged at least once, some were rechallenged two or three times. Serum was analysed prior to each challenge for specific IgE, IgG and IgG4 binding to crude CM protein as well as to individual allergens of CM.

RESULTS

The individual likelihood of outgrowing CMA significantly correlates with a low level of CM-specific IgE as well as a low level of specific IgE to α-lactalbumin, β-lactoglobulin (Bos d5.0102), κ-casein and α(s1) -casein. No significant correlation was found for IgE levels to total casein, lactoferrin, β-casein and β-lactoglobulin (Bos d5.0101) as well as IgG and IgG4 levels to α-lactalbumin, β-lactoglobulin and total casein.

CONCLUSIONS

CM-specific IgE is a good prognostic marker for persistence of CMA. In addition, component-resolved diagnostic showed similar results. However, in our view, the rising laboratory costs do not justify a measurement on a daily basis. Additional determination of specific IgG or IgG4 levels was not useful in predicting tolerance development in our study population.

The role of hen's egg-specific IgE, IgG and IgG4 in the diagnostic procedure of hen's egg allergy

BACKGROUND

Hen's egg (HE) allergy is a common disease in childhood. HE-specific serum IgE has been correlated with the outcome of oral food challenge tests, and diagnostic decision points have been described as helpful but still not sufficient to reduce the requirement for oral food challenges. The aim of the study was to correlate HE-specific IgE, IgG and IgG4 levels with the outcome of double-blind, placebo-controlled food challenges (DBPCFC) in patients with suspected HE allergy to improve diagnostic procedures.

METHODS

HE-specific IgE, IgG, and IgG4 levels were compared between 150 children with suspected HE allergy based on sensitization and/or patient's history who underwent DBPCFC. Sixty-six patients were HE-allergic (HE-sensitized with a positive DBPCFC), 48 HE-sensitized but tolerant (negative DBPCFC), and 36 patients were nonsensitized and tolerant (negative DBPCFC). Prior to food challenge HE-specific serum IgE, IgG, and IgG4 were measured with the Phadia CAP-system.

RESULTS

HE-specific IgE was significantly higher in HE-allergic patients than in clinically tolerant ones. However, there was no difference in HE-specific IgG and IgG4 concentrations between the patient groups.

CONCLUSION

A proposed cut-off level of 12 kU/l IgE would identify children above this level correctly as HE-allergic. The level of HE-specific IgG or IgG4 in serum of children with suspected HE allergy does not add any additional information in the diagnostic procedure of HE allergy. For diagnostic purposes, specific IgG or IgG4 should not routinely be tested.

The influence of testosterone substitution on bone mineral density in patients with Klinefelter's syndrome

The aim of this study was to clarify the extent of bone mineral deficiency in patients with Klinefelter's syndrome on the premise that testosterone substitution could prevent this deficiency. Bone mineral density was measured by single-photon absorptiometry in 42 patients with Klinefelter's syndrome, (21 patients without therapy, 10 with testosterone substitution before the age of 20 and 11 patients with testosterone substitution beginning after the age of 20). We found significantly lower bone mineral density in patients without therapy and in patients when the therapy began later compared to normal individuals. Patients with early therapy showed a high proportion of normal values of bone mineral density. We found a positive correlation between bone mineral density and plasma testosterone and a negative correlation between plasma testosterone and age for patients without therapy. These findings suggest that low testosterone levels before or during puberty cause inadequate bone development and low bone mineral density in Klinefelter's syndrome. Only early testosterone substitution may prevent bone mineral deficiency. Later substitution no longer affects bone mineral density.

Transiliac bone biopsy in osteoporosis: frequency, indications, consequences and complications. An evaluation of 99 consecutive cases over a period of 14 years

Bone biopsy is a diagnostic procedure restricted to untypical, unclear and complicated cases in evidence-based guidelines on diagnosis and treatment of osteoporosis. Its relevance has been a topic of recent controversial discussion. This study was performed to evaluate its role and relevance in routine use. A total of 99 horizontal transiliac bone biopsies performed over a time period of 14 years because of an osteological indication in one single centre were analysed, which reflects that bone biopsy followed about 0.003% of patients' consultations. Bone biopsies were indicated for osteoporotic males (n = 63) and premenopausal osteoporotic females (n = 18) without endocrine abnormality and normal immunofixation (serum and urine), suspected systemic/malignant disease such as mastocytosis, osteogenesis imperfecta, non-secreting plasmocytoma, metastatic infiltration (n = 16) and decreasing bone mineral density under anti-osteoporotic treatment (n = 2). The most frequent diagnoses besides osteoporosis were normal histology, borderline finding towards mild osteoporosis, and osteoporomalacia with relevant osteoidosis. In some cases, pathological findings in bone marrow were detected. In most cases (82/99), bone biopsy led to consequences in medical treatment. Following histopathological diagnosis, 16 patients did not receive any anti-osteoporotic treatment. In six patients, further diagnostic procedures were initiated because of bone histology. Bone biopsy was well tolerated and complications were rare and mild. In conclusion, despite all progress in non-invasive diagnostic procedures for metabolic bone diseases such as osteoporosis, there remains a small but significant subset of patients who may benefit from inclusion of bone biopsy into the diagnostic procedure.

The influence of local capsaicin treatment on small nerve fibre function and neurovascular control in symptomatic diabetic neuropathy

Topical treatment with capsaicin cream has been shown to be successful in the treatment of different symptomatic nerve disorders like diabetic neuropathy. Conflicting data exist on the effect of capsaicin on nerve function and neurovascular control especially in patients with diabetic neuropathy. The aim of this pilot study was to investigate the impact of topical capsaicin application on small nerve fibre function and neurovascular control. Capsaicin cream was applied to the feet of 13 patients with symptomatic diabetic neuropathy over a period of 8 weeks. Before and during the treatment period, we investigated the total symptoms score, the vibration, thermal (heat and cold) and pain perception thresholds, and the neurovascular responses to heat and acetylcholine stimuli. In addition, the serum plasma levels of substance P, a neurotransmitter of nociceptor C-fibres, were measured. A significant improvement in total symptoms score was observed during topical capsaicin treatment (18.3+/-3.2 vs. 14.3+/-3.3; p<0.05). An improvement in the heat perception threshold was also found (12.7+/-0.4 degrees C vs. 11.4+/-0.7 degrees C: p<0.05), while other sensory nerve fibre functions remained unchanged. No significant change in neurovascular control was observed, neither after mild thermal injury nor after stimulation with acetylcholine. Serum substance P levels increased after initiation of topical capsaicin treatment (72.9+/-5.8 pg/ml vs. 81.7+/-5.0 pg/ml; p<0.05), but returned to baseline levels during further treatment (77.4+/-8.3 pg/ml: n.s.). In conclusion, topical treatment with capsaicin cream over a period of 8 weeks in patients with symptomatic diabetic neuropathy is effective without adverse effects on nerve fibre function or neurovascular control.

[Multivariate analysis of factors influencing the effect of radiosynovectomy]

OBJECTIVE

In this prospective study, the time to remission after Radiosynovectomy (RSV) was analyzed and the influence of age, sex, underlying disease, type of joint, and duration of illness on the success rate of RSV was determined.

METHODS

A total number of 57 patients with rheumatoid arthritis (n = 33) and arthrosis (n = 21) with a total number of 130 treated joints (36 knee, 66 small and 28 medium-size joints) were monitored using visual analogue scales (VAS) from one week before RSV up to four to six months after RSV. The patients had to answer 3 times daily for pain intensity of the treated joint. The time until remission was determined according to the Kaplan-Meier survivorship function. The influence of the prognosis parameters on outcome of RSV was determined by multivariate discriminant analysis.

RESULTS

After six months, the probability of pain relief of more than 20% amounted to 78% and was significantly dependent on the age of the patient (p = 0.02) and the duration of illness (p = 0.05), however not on sex (p = 0.17), underlying disease (p = 0.23), and type of joint (p = 0.69).

CONCLUSION

Irrespective of sex, type of joint and underlying disease, a measurable pain relief can be achieved with RSV in 78% of the patients with synovitis, whereby effectiveness is decreasing with increasing age and progress of illness.

Comparison of quantitative ELISA and semiquantitative Dustscreen for determination of Der p 1, Der f 1, and Fel d 1 in domestic dust samples

BACKGROUND

Quantitative ELISA kits used for the measurement of indoor allergens are time-consuming. Therefore, an immunodot assay (Dustscreen) has been introduced, so that results can be obtained within 4 h. In order to assess the potential applications of the new method, we compared quantitative ELISA methods and Dustscreen.

METHODS

We compared the measurements of the mite allergens Der p 1 and Der f 1, and Fel d 1 by both Dustscreen and one brand of ELISA in 82 dust samples, and we also compared the measurement of the cat allergen Fel d 1 by Dustscreen and a different brand of ELISA in 77 dust samples. Optimum dilutions of dust extracts were compared between the ELISA and the immunodot assay. The nonparametric coefficient of correlation (Spearman's rank) was calculated for each allergen.

RESULTS

The immunodot assay was easy to perform. There was a good correlation between the results of the ELISA and Dustscreen (Der p 1: r=0.98, Der f 1: r=0.93, and Fel d 1: r=0.98). However, the coefficient of variation varied between 50% and 100% for Fel d 1 above 100 000 ng/g in Dustscreen. No cockroach allergen (Bla g 2) was detected in domestic dust samples in Berlin, and lower concentrations of group 2 allergen of mite (from not detectable to 19 500 ng/gm; median concentration 2000 ng/g) were found than mite group 1 allergens (sum of Der p 1 plus Der f 1: median 12 350 ng/g, minimum n.d., maximum 153 120 ng/g).

CONCLUSION

Our results indicate that quantification of indoor allergens in house-dust samples can be performed easily with Dustscreen, and both the technology and methodology are satisfactory.

Relationship between telomerase activation and HPV 16/18 oncogene expression in squamous intraepithelial lesions and squamous cell carcinomas of the uterine cervix

SILs (squamous intraepithelial lesions) comprise a wide spectrum of clinically and biologically heterogeneous lesions ranging from benign proliferations to precancerous lesions. Telomerase activation plays a critical role in cellular immortalization and might be important for malignant progression. The viral oncogenes E6 and E7 are the principal transforming genes of high-risk HPVs and are important in HPV-associated immortalization and neoplastic transformation. In this study we investigated the relationship between telomerase activity, telomerase RNA, and HPV 16/18 oncogene expression in low- and high-grade SILs and SCCs (squamous cell carcinomas) of the cervix uteri. Telomerase activity was examined by the TRAP-assay and expression of the telomerase RNA (hTR) and HPV 16/18 E6/E7 oncogenes by RNA/RNA-in situ hybridization (ISH). The associated HPV-type was determined by PCR. Telomerase activity was observed in 25/29 (86%) SCCs, 31/41 (76%) high-grade SILs, 6/14 (43%) low-grade SILs, and 1/28 (3.6%) normal cervical tissues. Expression of hTR and viral oncogenes increased significantly with histopathologic severity of the lesion (p < 0.0001). A correlation was found between telomerase activity and intensity of viral oncogene expression. These findings suggest that telomerase activation occurs early in cervical carcinogenesis and is predominantly found in high-grade SILs and cervical SCCs. Our findings support current experimental data that suggest that telomerase is at least partially activated by viral oncogenes of high-risk HPV types. Telomerase activity with concomitant strong viral oncogene expression might therefore characterize a subset of lesions that are at risk for malignant progression.

Infusion pump performance with vertical displacement: effect of syringe pump and assembly type

OBJECTIVE

To evaluate the effect of different infusion pump models on continuity of drug delivery during vertical displacement of syringe pumps.

DESIGN

Zero-drug delivery time (ZDDT), retrograde aspiration volume, and infusion bolus were recorded using the same syringe in three different models of syringe pump after lowering and elevating the pump. Compliance of each infusion assembly was measured using the occlusion release technique at 38 mmHg.

RESULTS

Lowering the pump by 50 cm at an infusion rate of 1 ml/h resulted in ZDDT values ranging from 2.78 +/- 0.29 to 5.99 +/- 1.09 min. Elevating the syringe pump to its original position caused infusion boluses between 44.1 +/- 3.2 and 77.1 +/- 5.1 microl. The results demonstrated that there are large differences between syringe pump models (F = 66.8, df = 2/33, p < 0.0001) and between pumps of the same model (F = 21.3, df = 1/34, p < 0.0001). A similar pattern was found in retrograde aspiration volume and infusion bolus.

CONCLUSION

All tested pumps led to clinically relevant flow irregularities during vertical displacement of the syringe pump. Thus, vertical displacement of any syringe pump connected to an infusion line delivering highly potent drugs at low infusion rates should be avoided. The variability across syringe pumps indicates that syringe pump design remains an area of potential further improvement for reducing the risk of adverse patient events.

Do antisiphon valves reduce flow irregularities during vertical displacement of infusion pump systems?

Vertical displacement of syringe pumps may cause irregular drug delivery due to hydrostatic pressure changes in the infusion line. The extent of flow fluctuations depends on the internal compliance of infusion lines, syringes and syringe pumps. We evaluated whether pressure regulation by antisiphon valves (ASV) reduces the flow variation during vertical displacement of 50 ml standard syringes and infusion pumps. An infusion assembly comprising a standard 50 ml BD Plastipak or a 50 ml Fresenius syringe, with syringe pump and 2 m low compliance infusion line was used for in vitro measurement of fluid delivery. The assembly was tested without ASV, and with two ASVs of differing operating pressure (ASV:75: valve opening pressure = 75 mmHg; ASV:155, 155 mmHg). Retrograde aspiration volume, zero-drug delivery time and valve opening bolus were determined after lowering the syringe pump by 50 cm. After elevating the syringe pump to its initial position the ensuing infusion bolus was recorded. Without an antisiphon valve the observed zero-drug delivery times after lowering the syringe pump were (mean +/- SD) 2.4 +/- 0.2 min using the BD Plastipak syringe and 4.09 +/- 0.55 min using the Fresenius syringe. Introduction of the antisiphon valve prolonged the zero drug delivery time 58% (ASV:75) and 88% (ASV:155) in the BD Plastipak syringe assembly and 43% (ASV:75) and 81% (ASV:155) in the Fresenius syringe assembly (P < 0.001). Antisiphon valves worsen flow irregularities caused by vertical displacement of syringe pumps and when used with delivery of concentrated inotropic drugs at low infusion rates, they may aggravate haemodynamic consequences of inconstant drug delivery.

[The effect of air within the infusion syringe on drug delivery of syringe pump infusion systems]

Application of highly concentrated short-acting vasoactive drugs in the critically ill patient requires precisely working syringe pump systems for continuous intravenous drug delivery. We performed a bench study to investigate the consequences of small amounts of air entrapped within a 50-ml infusion syringe. In particular we studied the effect of entrapped air on drug delivery after moderate vertical displacement of the pump by 50 cm (e.g. in preparation for transport) and the effect on the time required to trigger the pressure alarm after occlusion of the infusion line. At a flow rate of 1 ml/h, lowering the syringe pump prolonged the zero-drug delivery time from (mean +/- SD) 4.1 +/- 0.8 min (without air) to 6.2 +/- 0.9 (with 1 ml air) and to 13.1 +/- 0.9 min (with 2 ml of air, p < 0.001 for all comparisons). Entrapping of 2 ml of air within the syringe resulted in a 2.6-fold prolongation of the occlusion alarm time after accidental occlusion of the infusion line and a 3-fold increase of the resulting infusion bolus after occlusion. Enclosed air within infusion syringes considerably affects the syringe compliance. It increases the susceptibility of constant drug delivery to vertical displacement of syringe pumps and impairs the occlusion alarm function. Therefore, any air in syringe of infusion pump systems should be carefully removed. To avoid infusion boluses of short-acting vasoactive drugs after accidental occlusions, the occluded infusion line should be released to ambient pressure first.

Changes in pulmonary blood flow during gaseous and partial liquid ventilation in experimental acute lung injury

BACKGROUND

It has been proposed that partial liquid ventilation (PLV) causes a compression of the pulmonary vasculature by the dense perfluorocarbons and a subsequent redistribution of pulmonary blood flow from dorsal to better-ventilated middle and ventral lung regions, thereby improving arterial oxygenation in situations of acute lung injury.

METHODS

After induction of acute lung injury by repeated lung lavage with saline, 20 pigs were randomly assigned to partial liquid ventilation with two sequential doses of 15 ml/kg perfluorocarbon (PLV group, n = 10) or to continued gaseous ventilation (GV group, n = 10). Single-photon emission computed tomography was used to study regional pulmonary blood flow. Gas exchange, hemodynamics, and pulmonary blood flow were determined in both groups before and after the induction of acute lung injury and at corresponding time points 1 and 2 h after each instillation of perfluorocarbon in the PLV group.

RESULTS

During partial liquid ventilation, there were no changes in pulmonary blood flow distribution when compared with values obtained after induction of acute lung injury in the PLV group or to the animals submitted to gaseous ventilation. Arterial oxygenation improved significantly in the PLV group after instillation of the second dose of perfluorocarbon.

CONCLUSIONS

In the surfactant washout animal model of acute lung injury, redistribution of pulmonary blood flow does not seem to be a major factor for the observed increase of arterial oxygen tension during partial liquid ventilation.

Production of stem-cell transplants according to good manufacturing practice

Peripheral blood stem cells (PBSCs) are used for transplantation to reconstitute the hematopoietic system after high-dose chemotherapy. They are harvested from peripheral blood after mobilization by cytokines and/or chemotherapy. Further ex vivo manipulation steps (e.g., selection of CD34+ PBSCs, purging, expansion, and differentiation or gene transfer) can be performed. In 1997, more than 12,000 PBSC preparations were transplanted in Europe and the total number is steadily increasing [1]. To ensure quality and safety of the final cell products intended for clinical use, national and international guidelines and regulations have been issued. The implementation of a quality assurance (QA) program including the principles of good manufacturing practice (GMP) and a quality control system is a major requirement. GMP regulations apply to all phases of cell collection, processing, and storage, and to documentation, training of personnel, and equipment of the cell processing laboratory. They have to be followed by pharmaceutical companies and medical doctors who are involved in PBSC processing at academic institutions. The complicated regulatory network for the manufacturing of cell products will help to standardize these procedures and ensure consistent quality and safety in the long term. This will be in the interest of patients and reduce risks of application of individual cell preparations.

Gap-junctional coupling measured by flow cytometry

A method is described which reliably quantifies the degree of intercellular communication via gap junctions by combining a dye-loading technique with fluorescence-activated flow cytometry. Our experiments expand former measurements of other groups by analyzing the time- and density-dependent onset of coupling with a fixed ratio of donor to recipient cells. The high sensitivity of this technique provides a better resolution than the microelectrode technique and allows the detection of small changes in gap-junctional coupling by examining a large number of cells in a single experiment. Suspended cells were loaded with the membrane-permeable dye calcein AM, which is intracellularly hydrolyzed by nonspecific esterases, and the resulting polyanionic calcein is thus trapped inside these donor cells. Gap junctions, however, are permeable for this fluorescent dye, as can be observed when suspended donor cells are added to recipient cells (i.e., monolayer cultures) in which case cell-cell contact is established within less than 60 min. In addition, one of these two cell populations can also be stained with a membrane-resident dye (e.g., DiI), which facilitates the identification of different cell populations (donors, recipients, and noncoupled cells) not only by epifluorescence microscopy but also by flow cytometry. Our analyses reveal that junctional coupling depends not only on the connexin type (homo- or heterotypic junction) but also on the origin (species) of the contacting cells (homo- or heterospecific contact). We confirm earlier reports in which homotypic-homospecific coupling was demonstrated with different techniques in connexin-transfected HeLa and RIN cells as well as in BICR/M1R(k) and 3T3/SV40 cells. In contrast to other publications, we show that a significant heterotypic-homospecific coupling between Cx40- and Cx43-HeLa transfectants can be resolved, whereas no coupling was detected for heterotypic-heterospecific contacts between Cx40-HeLa transfectants and the Cx43-expressing cell lines BICR/M1R(k), 3T3/SV40, and RIN.