Interaction of biomechanics with extracellular matrix components in abdominal aortic aneurysm wall.

OBJECTIVE: Little is known about the interactions between extracellular matrix (ECM) proteins and locally acting mechanical conditions and material macroscopic properties in abdominal aortic aneurysm (AAA). In this study, ECM components were investigated with correlation to corresponding biomechanical properties and loads in aneurysmal arterial wall tissue. METHODS: Fifty-four tissue samples from 31 AAA patients (30♂; max. diameter Dmax 5.98 ± 1.42 cm) were excised from the aneurysm sac. Samples were divided for corresponding immunohistological and mechanical analysis. Collagen I and III, total collagen, elastin, and proteoglycans were quantified by computational image analysis of histological staining. Pre-surgical CT data were used for 3D segmentation of the AAA and calculation of mechanical conditions by advanced finite element analysis. AAA wall stiffness and strength were assessed by repeated cyclical, sinusoidal and destructive tensile testing. RESULTS: Amounts of collagen I, III, and total collagen were increased with higher local wall stress (p = .002, .017, .030, respectively) and strain (p = .002, .012, .020, respectively). AAA wall failure tension exhibited a positive correlation with collagen I, total collagen, and proteoglycans (p = .037, .038, .022, respectively). α-Stiffness correlated with collagen I, III, and total collagen (p = .011, .038, and .008), while ß-stiffness correlated only with proteoglycans (p = .028). In contrast, increased thrombus thickness was associated with decreased collagen I, III, and total collagen (p = .003, .020, .015, respectively), and AAA diameter was negatively associated with elastin (p = .006). CONCLUSIONS: The present results indicate that in AAA, increased locally acting biomechanical conditions (stress and strain) involve increased synthesis of collagen and proteoglycans with increased failure tension. These findings confirm the presence of adaptive biological processes to maintain the mechanical stability of AAA wall.

[Radiation therapy for the treatment of macroscopic canine anal gland tumors - a retrospective study]. / Strahlentherapie zur Behandlung makroskopischer Analbeuteltumoren des Hundes ­ eine retrospektive Studie.

INTRODUCTION: Canine anal gland tumors are locally invasive and early metastasize to the loco-regional pelvic lymph nodes. Radiation therapy is a good method for loco-regional tumor control, especially in inoperable tumors. Since the organs in the pelvic area are sensitive to both acute and late radiation damage (chronic diarrhea, bleeding, strictures or intestinal perforations) and such damage mainly depends on the fraction size, we examined the radiation protocol used in this study with a reduced number of fractions (hypofractionated) regarding effectiveness and side effects. This retrospective study describes 13 dogs with macroscopic anal gland carcinoma that were irradiated with imaging-guided, intensity-modulated radiation therapy with a hypofractionated curative protocol of 12 × 3,8 Gy. Gross pathology was either in the region of the anal gland and/or in the sublumbar lymph nodes. Ten of the 13 dogs had advanced tumor diseases (stage 3a or 3b). The acute radiation reactions were mild to moderate and had been reported for some of the dogs in a previous study. The mean study time was 572 days (range 105-1292 days). Disease progression was observed or suspected in 7/13 dogs during the study period: local or loco-regional progression occurred in 3 dogs (23 %) and distant metastases in 4 dogs (31 %). Median progression-free survival was 480 days (95 %CI, 223-908), median survival was 597 days (95 %CI, 401-908). One year after treatment, 76,9 % (95 %CI, 53,5-100) of the dogs were still alive. The likelihood of tumor progression was lower with increasing age, otherwise none of the examined tumor or patient factors showed a prognostic influence on progression or survival time. No clinically relevant late side effects were observed apart from slight alopecia, pigmentation changes or dry, scaly skin, Medium to long-term tumor control can be expected in dogs with macroscopic anal gland tumors treated with a moderately hypofractionated radiation therapy protocol (12 × 3,8 Gy). During long-term monitoring no serious side effects or side effects requiring treatment were observed.

INTRODUCTION: Les tumeurs des glandes anales canines sont localement invasives et métastasent rapidement dans les ganglions lymphatiques loco-régionaux pelviens. La radiothérapie est une bonne méthode de contrôle des tumeurs loco-régionales, en particulier pour les tumeurs inopérables. Étant donné que les organes de la région pelvienne sont sensibles aux dommages aigus et tardifs de la radiation (diarrhée chronique, saignements, sténoses ou perforations intestinales) et que ces dommages dépendent principalement de la taille des fractions, nous avons étudié le protocole de radiations utilisé dans cette étude avec un nombre réduit de fractions (hypofractionné) en terme d'efficacité et d'effets secondaires. Cette étude rétrospective décrit 13 chiens atteints de carcinome macroscopique de la glande anale qui ont été traités par une radiothérapie à modulation d'intensité guidée par imagerie avec un protocole curatif hypofractionné de 12 × 3,8 Gy. La pathologie macroscopique se trouvait soit dans la région de la glande anale et/ou dans les ganglions lymphatiques sublombaires. Dix des 13 chiens présentaient des pathologies tumorales avancées (stade 3a ou 3b). Les réactions aiguës aux radiations étaient légères à modérées et avaient été signalées pour certains des chiens dans une étude précédente. La durée moyenne de l'étude était de 572 jours (fourchette 105­1292 jours). Une progression de la maladie a été observée ou suspectée chez 7/13 chiens au cours de la période d'étude : une progression locale ou loco-régionale est survenue chez 3 chiens (23 %) et des métastases à distance chez 4 chiens (31 %). La survie médiane sans progression était de 480 jours (95 %CI, 223­908), la survie médiane était de 597 jours (95 %CI, 401­908). Un an après le traitement, 76,9 % (95 %CI, 53,5­100) des chiens étaient encore en vie. La probabilité de progression de la tumeur était plus faible avec l'âge, mais aucun des facteurs examinés concernant la tumeur ou le patient n'a montré d'influence pronostique sur la progression ou la durée de survie. Aucun effet secondaire tardif cliniquement pertinent n'a été observé, hormis une légère alopécie, des changements de pigmentation ou une peau sèche et squameuse, On peut s'attendre à un contrôle tumoral à moyen et long terme chez les chiens atteints de tumeurs macroscopiques de la glande anale traités par un protocole de radiothérapie modérément hypofractionnée (12 × 3,8 Gy). Au cours du suivi à long terme, aucun effet secondaire grave ou nécessitant un traitement n'a été observé.

[Massive unresectable hepatocellular carcinoma in a dog treated with -intensity-modulated radiation therapy]. / Massives inoperables hepatozelluläres Karzinom bei einem Hund behandelt mittels intensitätsmodulierter Strahlentherapie.

INTRODUCTION: This case report describes a 12-year-old female spayed mixed-breed dog referred for treatment of a large, inoperable hepatocellular carcinoma. A computed tomography (CT) scan confirmed the previous ultrasonographic and laparoscopic findings of a large, lobulated, poorly defined mass on the left and central aspect of the liver. Multiple biopsies confirmed the diagnosis of hepatocellular carcinoma. Due to the large extent of the tumor, the vascular association to the Vena cava caudalis and the associated high risk of intraoperative bleeding, a resection of the mass was refrained from and a radiotherapeutic treatment was chosen. The dog underwent radiation therapy (RT) with a 6MV linear accelerator with 5×6 Gy, total dose 30 Gy. In the follow up examinations three months and one year after therapy, the dog presented in normal condition and had normal Alanine-amino-transferase (ALT) and alkaline phosphatase (AP). The tumor size measured in the CT-examinations decreased by 61% and 90%, respectively. Two years after radiation therapy the dog has a normal general condition and liver enzymes are within the normal limits.

INTRODUCTION: Ce rapport décrit le cas d'une chienne de race mixte, stérilisée, âgée de 12 ans et référée pour traitement d'un important carcinome hépatocellulaire inopérable. Une tomodensitométrie (TDM) a confirmé les résultats échographiques et laparoscopiques antérieurs, à savoir une grande masse mal définie sur la partie gauche et centrale du foie. De multiples biopsies ont confirmé le diagnostic de carcinome hépatocellulaire. En raison de l'étendue de la tumeur, de l'association à la veine cave caudale et du risque élevé associé d'hémorragies peropératoires, on a renoncé à une résection de la masse et un traitement radiothérapeutique a été choisi. Le chien a subi une radiothérapie (RT) avec un accélérateur linéaire de 6 MV avec 5 × 6 Gy, dose totale 30 Gy. Lors des examens de suivi, trois mois et un an après le traitement, le chien présentait un état normal et avait une alanine-amino­-transférase (ALT) et une phosphatase alcaline (PA) normales. La taille de la tumeur mesurée lors des examens tomodensitométriques avait diminué de 61% respectivement de 90%. Deux ans après la radiothérapie, le chien présente un état général normal et les enzymes hépatiques sont dans la norme.

[Clinical pathway for total knee arthroplasty (EGON). II. The impact of enhanced patient information]. / Klinischer Behandlungspfad zur Implantation einer Oberflächenknieendoprothese (EGON). II: Effekt einer intensivierten Patienteninformation.

PURPOSE: The effects of the introduction of a clinical pathway and enhanced patient information on patients' satisfaction were investigated in the current study. MATERIAL AND METHODS: In a prospective cohort study patients were systematically interviewed about the preparation and the clinical course during implantation of a total knee arthroplasty. The study included 132 patients before (cohort I) and 128 after (cohort II) introduction of a clinical pathway. All patients of cohort II were offered the opportunity to attend an enhanced patient information lecture. The collected data were analysed in a descriptive manner. Items with more than 10% negative answers constituted the need for improvement. RESULTS: Regarding preparation of the operation there was a need for improvement of 11 items in cohort I and 4 in cohort II. With respect to the clinical course there was a slight increase from 6 to 7 items that required improvement. The enhanced information about the treatment and the clinical course were assessed positively. Patients were unsatisfied with the individual explanation of the X-rays. Of 128 patients from cohort II, 58 decided to participate in the information session for patients. The patients who had attended were more interested in receiving additional information. The success of the operation (gain in WOMAC score of at least 20%) showed a substantial effect on patient satisfaction. CONCLUSION: With increased patient information the knowledge and patient satisfaction within clinical pathways can be improved.

[Risk stratification of emergencies during the COVID-19 pandemic within the emergency department]. / Risikostratifizierung von Notfällen während der COVID-19-Pandemie in der Zentralen Notaufnahme.

BACKGROUND: The COVID-19 pandemic represents a complex challenge for medical staff within emergency departments (ED) of hospitals at all care levels. Beside regular emergency care, rapid detection and isolation of COVID-19 cases are obligatory for prevention of internal viral transmission and efficient medical staff protection. METHODS: In this study a model of risk stratification for suspected SARS-CoV­2 and COVID-19 cases was developed on the basis of epidemiologic criteria of the Robert-Koch Institute including five risk categories (RC). The model was implemented in a hospital of basic and regular care level. By combination of risk categories with specific isolation, hygienic and personal protection procedures all areas of the ED were restructured. In a retrospective study all inpatient cases (n = 491) were re-evaluated during a 4-week interval (26 March-26 April 2020). RESULTS: In the study population 25 SARS-CoV­2 positive cases (5.2%) were identified. These cases were categorized according to the risk stratification model as follows: RC I-confirmed SARS-CoV­2 infection 36% (n = 9), RC II-reasonable suspected cases 32% (n = 8), RC III-differential diagnostic cases 12% (n = 3), RC IV-low probability 8% (n = 2) and RC V-no evidence 12% (n = 3). No viral transmission was detected during the whole period within medical staff and patients of the ED. CONCLUSIONS: Introduction of COVID-19 risk categories within the ED permits central control of important hygienic processes with respect to SARS-CoV­2 infection probability. By continuous re-evaluation of case definitions local outbreaks can be used to adapt criteria within the risk categories. Risk stratification of COVID-19 cases allows for a strict separation of COVID-19 and non-COVID-19 emergencies and thus ensures effective infection prevention of medical staff and patients.

[Peripheral nerve blocks of the lower extremities. Clinical and practical aspects]. / Periphere Nervenblockaden an der unteren Extremität. Klinisch-praktische Aspekte.

Peripheral nerve blocks (PNBs) of the lower extremities are effective techniques for anesthesia and postoperative pain control. So far, these techniques have been used less frequently than PNBs of the upper limb. Nevertheless, growing awareness of complications of neuroaxial techniques, improved equipment and modern techniques for nerve localization have led to an increased use of PNBs of the lower limb. Anesthesiologists should be familiar with the anatomical basics and procedural details of these PNBs. They should also know the typical complications and side-effects and thoroughly inform patients about such potential problems. Continuous PNBs (perineural catheters) allow the benefits of PNBs to be prolonged into the postoperative period. Compared to continuous neuroaxial techniques continuous PNBs are equally effective for pain control but seem to be associated with fewer complications and side-effects.

[Acromegaly due to a pituitary tumor in a dog - diagnosis, therapy and long-term follow-up]. / Akromegalie aufgrund eines Hypophysentumors bei einem Hund ­ Diagnose, Therapie und Verlauf.

INTRODUCTION: Acromegaly due to a pituitary tumor has so far only been described in 3 dogs. The present case report describes a 7-year-old male-castrated Labrador Retriever which was referred because of difficult-to-control diabetes. Physical examination revealed markedly enlarged head, tongue and paws, widened interdental spaces and thickening of the skin in the head and neck area. IGF-1 and GH were increased and the latter continued to be abnormal after somatostatin application. Computed tomography demonstrated a space-occupying lesion in the pituitary gland and the diagnosis of acromegaly due to a GH-producing tumor of the pituitary was made. The dog underwent radiation therapy with a 6MV linear accelerator (3×8Gy) and improved substantially. Two and a half years after radiation therapy the dog developed lethargy and anorexia and was euthanized. Necropsy was not permitted. This case report represents the description of a dog suffering from pituitary-dependent acromegaly which was successfully treated and had a long-term survival.

INTRODUCTION: L'acromégalie due à une tumeur hypophysaire n'a jusqu'à présent été décrite que chez 3 chiens. Le présent rapport de cas décrit un Labrador Retriever de 7 ans mâle castré, qui a été référé en raison d'un diabète difficile à contrôler. L'examen physique a révélé une tête, une langue et des pattes de taille nettement augmentée, des espaces interdentaires élargis et un épaississement de la peau dans la région de la tête et du cou. L'IGF-1 et la GH étaient augmentées et la seconde restait anormale après l'application de somatostatine. La tomodensitométrie a mis en évidence une masse dans la région de l'hypophyse et le diagnostic d'acromégalie due à une tumeur de l'hypophyse productrice de GH a été posé. Le chien a subi une radiothérapie avec un accélérateur linéaire de 6MV (3×8Gy) et son état s'est considérablement amélioré. Deux ans et demi après la radiothérapie, le chien développa une léthargie et une anorexie et fut euthanasié. L'autopsie n'a pas été autorisée. Ce rapport de cas représente la description d'un chien souffrant d'acromégalie dépendant de l'hypophyse, traité avec succès et ayant une survie à long terme.

Dosimetric benefit of adaptive radiotherapy in the neoadjuvant management of canine and feline thymoma-An exploratory case series.

While surgery is the treatment of choice for thymomas, complete excision is not possible in a significant proportion of cases. For these patients, radiotherapy can be used as neoadjunctive, post-operative adjunctive or sole therapy. During radiotherapy, rapid biological clearance of tumour cells is often observed, requiring adaptation of the treatment plan. Adaptive radiation therapy (RT) is a dynamic process, whereby the treatment plan is altered throughout the treatment course due to changes in morphologic, functional or positioning changes. With the hypothesis, that individually adapted replanning will massively reduce the dose to organs at risk (OAR) in a fast-changing environment such as a rapidly responding thymoma, the dosimetric impact of adaptive treatment planning in 5 patients with large thymoma was measured. In all patients rapid tumour-shrinkage of the gross tumour volume was observed after 1 week of therapy, with a mean shrinkage of 31.0% ± 15.2%, or a tumour regression of 5.2% per day. In consequence, there was a considerable change in position of organs such as heart and lung, both of them moving cranially into the high dose area upon tumour regression. After mid-therapy replanning, the dose to OAR was significantly reduced, with -18.2% in the mean heart dose and -27.9% in the V20 lung dose. Adaptive planning led to a significantly reduced radiation dose and hence protection of OAR for these patients. It can be concluded that adaptive replanning should be considered for canine and feline thymoma patients receiving fractionated RT.

A prospective pilot study on early toxicity from a simultaneously integrated boost technique for canine sinonasal tumours using image-guided intensity-modulated radiation therapy.

In order to overcome the common local treatment failure of canine sinonasal tumours, integrated boost techniques were tried in the cobalt/orthovoltage era, but dismissed because of unacceptable early (acute) toxicity. Intriguingly, a recent calculation study of a simultaneously integrated boost (SIB) technique for sinonasal irradiation using intensity-modulated radiation therapy (IMRT) predicted theoretical feasibility. In this prospective pilot study we applied a commonly used protocol of 10 × 4.2 Gy to the planning target volume (PTV) with a 20%-SIB dose to the gross tumour volume (GTV). Our hypothesis expected this dose escalation to be clinically tolerable if applied with image-guided IMRT. We included 9 dogs diagnosed with sinonasal tumours without local/distant metastases. For treatment planning, organs at risk were contoured according to strict anatomical guidelines. Planning volume extensions (GTV/CTV/PTV) were standardized to minimize interplanner variability. Treatments were applied with rigid patient positioning and verified daily with image guidance. After radiation therapy, we set focus on early ophthalmologic complications as well as mucosal and cutaneous toxicity. Early toxicity was evaluated at week 1, 2, 3, 8 and 12 after radiotherapy. Only mild ophthalmologic complications were found. Three patients (33%) had self-limiting moderate to severe early toxicity (grade 3 mucositis) which was managed medically. No patient developed ulcerations/haemorrhage/necrosis of skin/mucosa. The SIB protocol applied with image-guided IMRT to treat canine sinonasal tumours led to clinically acceptable side effects. The suspected increased tumour control probability and the risk of late toxicity with the used dose escalation of 20% has to be further investigated.

The nuclear factor YY1 participates in repression of the beta-casein gene promoter in mammary epithelial cells and is counteracted by mammary gland factor during lactogenic hormone induction.

Expression of the beta-casein milk protein gene in the mammary epithelial cell line HC11 is primarily regulated at the transcriptional level. A 338-bp segment of promoter sequence 5' of the transcription start site is sufficient to confer inducibility by the lactogenic hormones insulin, glucocorticoid hormone, and prolactin. Positively and negatively acting promoter elements and specific DNA binding proteins have been identified. The binding of the mammary gland factor MGF to a site between -80 and -100 is indispensable for hormonal induction of transcription. Binding of MGF activity to DNA is greatly enhanced by the action of the lactogenic hormones. Repression of transcription in the uninduced state is mediated by a promoter element located adjacent to the MGF binding site at positions -110 to -150. This repressor element consists of two interacting protein binding sites. A nuclear factor that binds specifically to the proximal site between positions -110 and -120 has been characterized and found to be identical with the nuclear factor YY1 (delta, NF-E1). YY1 does not bind to the distal site. The simultaneous mutation in the proximal and the distal sites results in high, hormone-independent transcription. This finding suggests that YY1 plays a functional role in the repression and acts in conjunction with a second DNA binding protein. Comparison of YY1 DNA binding activity in uninduced and hormone-induced cells showed that relief of repression is not mediated by changes in the concentration or binding affinity of YY1. Infection of HC11 cells with a YY1-expressing recombinant retrovirus resulted in overexpression of YY1 but did not suppress hormonal induction. The addition of purified MGF decreased YY1 binding to its DNA recognition site in vitro. This finding indicates that MGF regulates the DNA binding activity of YY1 and thereby may cause the relief of transcriptional repression.

Safety, tolerability and pharmacokinetic properties of the novel triazene TriN 2755 in tumour bearing dogs - a phase I study†.

TriN 2755 is an alkylating antineoplastic agent for intravenous (IV) use, carrying the triazene group as the cytotoxic principal. Using a standard 3 + 3 design, a phase I study was performed in tumour bearing dogs to determine the maximum tolerated dose (MTD), the dose limiting toxicity (DLT), and pharmacokinetic (PK) profile of TriN 2755. Thirty dogs were included in the study. TriN 2755 was administered over 20 min on two consecutive weeks per month for a total of three cycles. The starting dose was 25 mg kg-1 and the MTD was 74.6 mg kg-1 . Three dogs experienced DLT, which was characterized by gastrointestinal adverse events. The PKs of TriN 2755 and its main metabolites in plasma and sputum are described in a two-compartment model. The response rate for 19 of 30 dogs was 47.3% (six partial remission, three stable disease) and the median progression-free interval (PFI) for the responders was 47 days (range: 21-450 days).

A complication probability planning study to predict the safety of a new protocol for intracranial tumour radiotherapy in dogs.

Technical advances make it possible to deliver radiation therapy for canine intracranial tumours in fewer fractions, under the assumption of equivalent tumour control. With the aim of estimating the late toxicity risk profile for various tumour sizes and locations, the present paper evaluates the normal tissue complication probability (NTCP) values for the intracranial organs at risk. By making isoeffect calculations, a new 10-fraction radiation protocol was developed with the same tumour control probability (TCP) as a currently used 20-fraction standard protocol, and complication risk profiles for brain, brainstem and optic chiasm were modelled using a representative population of 64 dogs with brain tumours. For >59% of cases, the new 10-fraction protocol yielded an acceptable, low risk estimate of late toxicity (<10%). Our calculations suggest that it may be safe to treat small to intermediate-sized tumours that are neither located near the optic chiasm nor at the brainstem with 10 daily fractions of 4.35 Gy.

Outcome in dogs with advanced (stage 3b) anal sac gland carcinoma treated with surgery or hypofractionated radiation therapy.

Stage 3b anal sac gland carcinoma (ASGC) can be life-threatening. A surgical approach is not always possible or may be declined. Dogs with stage 3b ASGC treated with surgery or conformal radiation therapy (RT) with 8 × 3.8 Gy (total dose 30.4 Gy, over 2.5 weeks) were retrospectively evaluated. Patient characteristics, median progression-free interval (PFI) and median survival time (MST) were compared. Twenty-eight dogs were included; 15 underwent surgery, 13 underwent RT. At the time of presentation, 21% showed life-threatening obstipation and 25% showed hypercalcaemia. PFI and MST for surgery cases were 159 days (95% CI: 135-184 days) and 182 days (95% CI: 146-218 days), both significantly lower than for RT cases with 347 days (95% CI: 240-454 days) and 447 days (95% CI: 222-672 days), (P = 0.01, P = 0.019). Surgery as well as RT led to a fast relief of symptoms. PFI and survival of surgical patients were significantly inferior to that of a comparable patient group treated with conformal hypofractionated RT.

Mammary gland factor activated by prolactin on mammary epithelial cells and acute-phase response factor activated by interleukin-6 in liver cells share DNA binding and transactivation potential.

We have studied transcription factors that are coupled to the activation of cytokine receptors in liver and in mammary epithelial cells. Interleukin-6 (IL-6) causes the rapid activation of the acute-phase response factor (APRF) in the liver of animals during acute inflammation and in cultured human hepatoma cells (HepG2) and induces the transcription of the acute-phase protein genes, e.g. alpha 2-macroglobulin (alpha 2-M). In the mammary gland and in cultured HC11 mammary epithelial cells, milk protein genes, e.g. beta-casein, are induced by the lactogenic hormones, insulin, glucocorticoids, and PRL. The induction of the beta-casein gene promoter is preceded by the activation of the mammary gland factor (MGF). We have compared the DNA binding sequences of APRF and MGF, 5'-CTTCTT/GGGAATT-3', and have found that they coincide in 11 of 12 positions. Bandshift experiments and oligonucleotide competition experiments showed that both factors, MGF and APRF, are able to bind to the IL-6 response element of the alpha 2-M gene promoter and to the lactogenic hormone response element of the beta-casein gene promoter with very similar specificities. Partial proteolytic digestion of APRF and MGF DNA complexes yielded similar clipping patterns. The UV cross-linked DNA complexes of both transcription factors were of the same apparent molecular mass. IL-6 activation of APRF in HepG2 cells can be observed within minutes. MGF induction by PRL in HC11 cells occurs with similar kinetics. The synergistic action of glucocorticoids and PRL is necessary for the induction of the beta-casein gene, but PRL is sufficient for MGF activation.(ABSTRACT TRUNCATED AT 250 WORDS)

Serotonin-2 receptors and human sleep: effect of a selective antagonist on EEG power spectra.

To investigate the effect on the sleep EEG, a 1-mg oral dose of SR 46349B, a novel 5-HT2 antagonist, was administered three hours before bedtime. The drug enhanced slow wave sleep (SWS) and reduced stage 2 without affecting subjective sleep quality. In nonREM sleep (NREMS) EEG slow-wave activity (SWA; power within 0.75-4.5 Hz) was increased and spindle frequency activity (SFA; power within 12.25-15 Hz) was decreased. The relative NREMS power spectrum showed a bimodal pattern with the main peak at 1.5 Hz and a secondary peak at 6 Hz. A regional analysis based on bipolar derivations along the antero-posterior axis revealed significant 'treatment' x 'derivation' interactions within the 9-16 Hz range. In enhancing SWA and attenuating SFA, the 5-HT2 receptor antagonist mimicked the effect of sleep deprivation, whereas the pattern of the NREMS spectrum differed.

Studies on the mechanism of induction of microsomal cytochrome P452 and peroxisomal bifunctional enzyme mRNAs by nafenopin in primary cultures of adult rat hepatocytes.

The amount of the two mRNAs although lower in cultured hepatocytes than in freshly isolated cells was found to be rapidly inducible upon the addition of 32 microM nafenopin. The induction of cyt.P452 mRNA always preceded the induction of PBE mRNA, but for both, the maximal induction (10-20-fold over control) was obtained within 24 hr and was achieved by transcriptional activation. At early time points (1 and 2 hr after the addition of nafenopin), in the absence of on-going protein synthesis, the amount of cyt.P452 mRNA (and not of PBE mRNA) was transiently higher in the presence of cycloheximide and nafenopin than in the presence of nafenopin alone.

Hormonal regulation of transcription factor activity in mammary epithelial cells.

The multihormonal control of milk protein gene transcription in mammary epithelial cells has been investigated. Although the hormones regulating milk protein gene expression are known, the interaction of the signal transduction pathways of steroid (glucocorticoids) and peptide (insulin and prolactin) hormones remains undefined in molecular terms. These signals converge on the level of nuclear factors binding to regulatory elements in the beta-casein gene promoter. The promoter has a modular architecture and is composed of positive and negative response elements. Nuclear transcription factors which bind to these elements have been identified. The mammary gland factor, MGF, is an essential mediator of lactogenic hormone action and is itself positively regulated in its DNA binding activity. It binds to the promoter region between positions -80 to -100. MGF counteracts a repressor element, constituted by two components, which is located adjacent to the MGF binding site at positions -100 to -150. The transcription factor YY1 binds to the proximal half of the repressor element which overlaps with the MGF binding site. Specific single-stranded DNA binding proteins contribute to the negative regulation of the promoter by interacting with sequence elements between -160 and -190. DNA binding of these proteins is negatively regulated by the lactogenic hormones.

Molecular diagnosis of Ewing tumors: improved detection of EWS-FLI-1 and EWS-ERG chimeric transcripts and rapid determination of exon combinations.

Most Ewing tumors (ET), including Ewing sarcomas, peripheral primitive neuroectodermal tumors (PNET), and Askin's tumors, can be defined according to the specific chromosomal translocations t(11;22)(q24;q12) (EWS-FLI-1) or t(21;22)(q21;q12) (EWS-ERG). Detection of the chimeric RNA transcripts by reverse transcriptase-polymerase chain reaction (RT-PCR) has greatly facilitated the diagnosis of ET. Because of variable chromosomal breakpoint locations, however, the EWS gene fusions with FLI-1 and ERG genes are highly heterogenous, resulting in different sizes of the amplification products. To improve the diagnostic usefulness of the RT-PCR assay, we have developed an assay to detect chimeric mRNA transcripts by nested RT-PCR, followed by digestion of the PCR fragments with three different restriction endonucleases. This allows confirmation of the specificity of the PCR product and provides a rapid method to determine the combination of exons present in a transcript. In the 12 Ewing tumors tested, five different exon combinations were detected. In nine repeat biopsies of four patients, the case-specific translocation remained unchanged. One additional central PNET had no ET-specific translocation. In conclusion, the suggested combination of RT-PCR and restriction analysis of the PCR products allows a rapid and specific determination of ET-specific translocations.

Hepatitis C virus infection: 10 years after the discovery of the virus.

The hepatitis C virus (HCV) causes an acute but very often chronic liver disease. An estimated 3% of the world population is chronically infected with HCV. Chronic hepatitis C is the major cause of cirrhosis and hepatocellular carcinoma (HCC), which most often lead to liver transplantation. HCV is a single-stranded enveloped RNA virus; it belongs to the flaviviridae family. The virus has been classified into six genotypes, some of which are distributed worldwide, others of which are confined to more restricted areas. The genotype is an independent predictor of response to antiviral treatment. Blood transfusion was a major risk factor for acquiring HCV infection before donor screening for surrogate marker testing for non-A, non-B (NANB) hepatitis began in the mid-1980s, followed by screening for antibody to HCV in 1990. Today, intravenous drug use and high-risk sexual activity are the most frequently identified risk factors associated with HCV infection. The prevalence of people with unknown HCV infection worldwide is high, so it is necessary to screen people with risk factors. The treatment of patients with chronic HCV infection who have not been treated previously should consist of interferon alpha (IFN-alpha) and ribavirin.