A DNA-binding domain swap converts the invertase gin into a resolvase

DNA resolvases and invertases are closely related, yet catalyze recombination within two distinct nucleoprotein structures termed synaptosomes and invertasomes, respectively. Different protein-protein and protein-DNA interactions guide the assembly of each type of recombinogenic complex, as well as the subsequent activation of DNA strand exchange. Here we show that invertase Gin catalyzes factor for inversion stimulation dependent inversion on isolated copies of sites I from ISXc5 res, which is typically utilized by the corresponding resolvase. The concomitant binding of Gin to sites I and III in res, however, inhibits recombination. A chimeric recombinase, composed of the catalytic domain of Gin and the DNA-binding domain of ISXc5 resolvase, recombines two res with high efficiency. Gin must therefore contain residues proficient for both synaptosome formation and activation of strand exchange. Surprisingly, this chimera is unable to assemble a productive invertasome; a result which implies a role for the C-terminal domain in invertasome formation that goes beyond DNA binding.

Identification of the EGF/EGF-R system in the oviduct and endometrium of pigs in early stages of pregnancy and early conceptus

In the oviduct and endometrium, higher mRNA amounts encoding for EGF were found on day 6 and 12 in cyclic and on day 6 in pregnant pigs compared to signals on day 1. Reproductive state related changes could also be detected for TGFalpha mRNA in cyclic and pregnant pig oviduct but not in the endometrium. EGF-R protein concentration was higher (P < 0.05) in oviductal membranes on day 1 of the pregnancy (42.6 +/- 16.5 fmol mg(-1) protein) compared to day 6 and 12 (21.6 +/- 6.0 fmol mg(-1) protein and 17.1 +/- 3.8 fmol mg(-1) protein). In the endometrium EGF-R protein concentrations increased (P < 0.05) on day 1 (14.7 +/- 4.8 fmol mg(-1) protein) to day 6 (29.0 +/- 6.8 fmol mg(-1) protein) and day 12 (27.5 +/- 7.0 fmol mg(-1) protein) of pregnancy. The mature EGF-R protein (170 kDa) was verified in oviductal and endometrial membranes of all pregnant pigs investigated. A biologically intact EGF-R could be detected in all samples by means of autophosphorylation assay. Weak EGF mRNA signals were found in the expanded and filamentous blastocysts. No TGFalpha transcripts could be amplified during the embryonic stages. Only low amounts of EGF-R mRNA could be detected in zygotes and in filamentous blastocysts.

Saisonale Einflüsse auf die Konzentration von Progesteron im Blutplasma von Müttern der Rasse Schwarzköpfiges Fleischschaf (Kurzmitteilung)

Abstract. Title of the paper: Seasonal influences on blood plasma progesterone concentration in ewes of Black head Mutton sheep breed (short communication) In 71 Black head mutton sheeps on pasturing and housing were determined from the year 1995 to 1997 and there in the period from March to October the concentration of blood progesterone for determination of onset of estrus. The level of blood progesterone reported, on literature also, no cycle on this period. The investigation of 6 of this sheeps with ultrasonography had the result of ovarian activity with follicles from 2 mm to 7 mm in diameter, but no cycle was determined. The progesterone level of minimum and maximum on all years differed from March to beginning of September between 0,33 ng/ml and 2,15 ng/ml blood progesterone, after this to October between 0,82 ng/ml and 4,25 ng/ml blood progesterone. The pregnant sheeps detected blood progesterone concentrations from 5,50 ng/ml to 13,55 ng/ml blood progesterone (twins). The corpus luteum activity may be is prevalent on the blood progesterone level up 2 ng/ml and pregnancy up 5 ng/ml blood progesterone. The detectability of blood progesterone and supplemented ultrasonography of ovary possess the possibility recording of onset cycle activity and early pregnancy diagnosis.

Muskelwachstum und IGF-I bei Schweinen unterschiedlichen Geschlechts*

Abstract. Title ofthe paper: Growth of skeletal muscle and IGF-I in pigs of different sex IGF-I is a pluripotent factor that is involved in regulation of growth, differentiation and a large number of functions in numerous tissues and their cells. IGF-I is synthesized by hepatocytes (endocrine role) and several extrahepatic tissues (e.g. skeletal muscle; autoerine and paracrine role). In our study, we describe the postnatal growth of the skeletal muscles in pigs of various sex taking into account the possible influence of endogenous IGF-I. The investigation was made on 42 crossbred pigs. Seven blood samples and 4 biopsy samples of two muscles (M. longissimus dorsi and M. triceps brachii) were taken for the determination of IGF-I blood plasma concentration and muscle fibre diameter, respectively as well as for further muscle structural and biochemical traits. IGF-I plasma concentrations show an increase during fattening with significantly highest levels for boars. Phenotypic differences between sows and boars in thickness of Shoulder muscle are proven after the day 181 with ultrasonography because significant differences were detected in mean muscle area of caput longum musculi triceps brachii between sows and boars and barrows (180th day of life). There are no significant differences in mean muscle fibre diameter of both muscles between sexes. A group of animals with high mean diameter in muscle fibres (day 200) of M. triceps brachii has significantly higher IGF-I concentrations in blood plasma than a group of animals with low muscle fibre diameter in the same muscle.

Generality and specificity of emotion-recognition deficit in schizophrenic patients with positive and negative symptoms

Schizophrenic patients with positive and negative symptoms, as well as non-patient control subjects, were asked to recognize emotional stimuli of happy, sad, and neutral facial expressions. Dependent measures were the percentage of correct responses, and the incorrect use of an emotion category owing to false recognition. Schizophrenic patients with negative symptoms exhibited a generalized emotion-recognition deficit, and their use of emotion categories during false recognition was random. Schizophrenic patients with positive symptoms showed a deficit in their recognition of 'sad' emotion and were 'positively biased' to the category 'happy' as reflected by its most frequent usage during false recognition.

Induction of nitric oxide synthase and dual effects of nitric oxide and cyclooxygenase products in regulation of arterial contraction in human septic shock

BACKGROUND

The role of endogenous nitric oxide (NO) and cyclooxygenase metabolites was investigated in contractile responses of small omental arteries from patients with hyperdynamic septic shock.

METHODS AND RESULTS

Expression of inducible NO synthase (immunostaining) and a high but variable level of NO production (NO spin trapping) was detected in arteries from patients with septic shock. In these vessels, ex vivo contractile responses to the thromboxane A2 analogue U46619 and to low concentrations of norepinephrine (NE) (up to 10 micromol/L) were not significantly different from controls. However, higher concentrations of NE caused pronounced fading of contraction in septic but not in nonseptic arteries. Exposure to either the NO synthase inhibitor NG-nitro-L-arginine methyl ester or the cyclooxygenase inhibitor indomethacin had no effect in control vessels. However, both inhibitors increased the response to the contractile effects of the 2 agonists only in patients with septic shock. In contrast to NG-nitro-L-arginine methyl ester, which decreased the threshold concentration of the fading effect of NE, indomethacin abolished this effect in arteries from septic patients.

CONCLUSIONS

These results provide direct evidence for the induction of NO synthase in small arteries from patients with septic shock. They suggest that in these arteries, increased production of NO, in conjunction with vasodilatory cyclooxygenase metabolites, contributes to counteract hyperreactivity to agonists and decreases the cyclooxygenase product-mediated pronounced fading of contraction caused by a high concentration of NE.

Correspondence of emotional self-rating with facial expression

Emotional processing abilities are difficult to measure psychometrically. Ultimately their quantification has to rely on 'subjective' judgment thereby leaving open the problem of response biases. Assessments of autonomic arousal similarly provide a mere unspecified measurement of a specific emotion. A standardized mood induction procedure capable of obtaining reliable happy and sad mood changes in healthy subjects was used to demonstrate the effectiveness of this procedure. We performed a two-part experiment using a rater-based analysis of facial expressions. This entailed analyzing the emotion portrayed in the faces. The faces of 24 healthy subjects were videotaped during the mood induction procedure of happiness and sadness, respectively. A group of 20 raters naive to the experimental task and conditions rated the facial expressions on six basic emotions. Results showed that ratings corresponded with the facial expressions, which were reflecting the mood of the task condition. Subjects' facial expressions together with self-ratings demonstrate the successful applicability of this standardized mood induction procedure for eliciting happy and sad mood.

[Wound healing and hyperbaric oxygen. Experimental study of the angiogenesis phase in the rat]

Hyperbaric oxygen therapy (HBO) is widely reported as highly favourable to wound healing. The experimental models generally used to investigate its effects are difficult to set up and reliable quantification of the results obtained is rarely achieved. The underlying pathophysiological mechanisms occurring during HBO remain poorly understood and its mode of application for clinical practice is difficult to standardise. Our study was carried out to assess the contributions of oxygen and hyperbaric pressure on the initial steps of wound healing. It was based on qualitative and quantitative analysis of the development of the angiogenic process in a granulation tissue bud, using animals implanted with fibrin chambers, an in vivo model initially described by Dvorak in guinea pigs. In our study, rats were further submitted to HBO (OHB group) or hyperbaric air (Air-HB group) treatments. The control group (Control group) consisted of rats maintained in the treatment tank under normal atmospheric conditions. Nine specific parameters were determined and analysed during the course of the angiogenic process by classical histological techniques. The vascular density and the height of the bud were particularly examined at day 7, 14 and 21 following chamber implantation. At D7 the neovessel density and bud height were significantly higher in OHB group than in Air-HB or Control groups, thus confirming the beneficial effects of this treatment on the initial steps of wound healing. Nevertheless, the results reported herein also suggest a possible inhibitory effect of hyperbaric therapy alone on this very early process, although the pathophysiological significance of this effect on wound healing remains to be determined.

Subcortical correlates of differential classical conditioning of aversive emotional reactions in social phobia

BACKGROUND

Conditioning processes have been proposed to play a role in the development of anxiety disorders. As yet, the neurobiologic correlates of emotional learning have not been fully understood in these patients. Accordingly, brain activity was studied in subcortical and cortical regions involved in the processing of negative affect during differential aversive classical conditioning.

METHODS

Twelve patients with social phobia and 12 healthy control subjects were presented with paired conditioned (CS; neutral facial expressions) and unconditioned stimuli (US; negative odor vs unmanipulated air). Functional magnetic resonance imaging (fMRI) was utilized to examine regional cerebral activity during habituation, acquisition,a nd extinction trials. Activity was measured with echo-planar-imaging (EPI), and signal intensity in individually defined anatomic regions were analyzed.

RESULTS

Subjective ratings of emotional valence to the CS indicated that behavioral conditioning occurred in both groups. The presentation of CS associated with negative odor led to signal decreases in the amygdala and hippocampus of normal subjects, whereas an opposite increased activation in both regions was observed in patients. Regional differences were not found during habituation and extinction.

CONCLUSIONS

Results suggest that conditioned aversive stimuli are processed in subcortical regions, with phobic patients differing from control subjects.

The evolution of minimally invasive valve surgery--2 year experience

OBJECTIVES

The aim of the study was to evaluate the evolution of Port-Access minimally invasive mitral valve surgery to a robot assisted video assisted solo surgery approach.

METHODS

One hundred and twenty-nine patients with non-ischemic mitral valve disease underwent 3D-video assisted mitral valve surgery via a 4 cm right lateral minithoracotomy using femoro-femoral bypass and endoaortic clamping. Transcranial Doppler and continuous transesophageal echocardiography were used to monitor placement and positional stability of the endoclamp. After the initial series (group I, n = 62), a simplified solo surgical technique using voice controlled robotic assistance for videoscope guidance was used in the last 67 patients (group II).

RESULTS

After an initial learning curve and modifications of catheter design, the procedure could be steadily redefined and simplified. In the last 67 patients, the procedure was completed without the need for an additional assistant as 'solo surgery'. The mitral valve was repaired in 72 and replaced in all other patients. Duration of bypass and clamp time steadily improved during our study and in the most recent 67 patients average 107 +/- 34 and 48 +/- 16 min, respectively. The voice controlled robotic arm (AESOP 3000, Automated Endoscope System for Optimal Positioning) provided a stable and precise video image with excellent exposure of all valvular and subvalvular structures. Hospital mortality was high in the early series (mean survival 88.7% at 804 +/- 35 days; 95% CI: 735-873) and partially procedure related (aortic dissection in two patients). In group II, hospital mortality has declined to 3.0% (mean survival 97.0% at 568 +/- 12 days; 95% CI: 553-600).

CONCLUSION

Port-Access minimally invasive mitral valve surgery has evolved to be a reliable video assisted technique with reproducible results. Surgery can now be performed almost in the same time as with conventional techniques. Robotic assistance has enabled a solo surgery approach.

A tissue-like culture system using microstructures: influence of extracellular matrix material on cell adhesion and aggregation

Special microenvironmental conditions are required to induce and/or maintain specific qualities of differentiated cells. An important parameter is the three-dimensional tissue architecture that cannot be reproduced in conventional monolayer systems. Advanced tissue culture systems will meet many of these demands, but may reach their limits, especially when gradients of specific substances over distinct tissue layers must be established for long-term culture. These limitations may be overcome by incorporating microstructures into tissue-like culture systems. The microstructured cell support presented consists of a flat array of 625 cubic microcontainers with porous bottoms, in which cells can be supplied with specific media from both sides of the tissue layer. Permanent cell lines and primary rat hepatocytes have been used to test the culture system. In order to define reproducible conditions for tissue formation and for cell adherence to the structure, several ECM (extracellular matrix) components were tested for coating of microstructured substrata. The described tissue culture system offers great flexibility in adapting the cell support to specific needs.

Acetylcholine constrictor effect enhanced by hydrogen peroxide in ovalbumin-sensitised rat tracheal muscle

Ten Sprague-Dawley male rats were sensitised with ovalbumin. The effect of hydrogen peroxide on the constrictor effect of acetylcholine was studied in the isolated tracheal muscle. Preincubation with hydrogen peroxide (H2O2) 10(-3) M (1 min/30 min) does not modify the acetylcholine constrictor effect in the control group. Ovalbumin sensitisation enhanced the acetylcholine constrictor effect (mean value of 19%) irrespective of dosage, comparatively with the control group. Short- and long-term preincubation with hydrogen peroxide enhanced the acetylcholine effect in the sensitised group, irrespective of dosage, comparatively with the control group. A relationship between dosage, contractile response and time of incubation was noticed only in the sensitised group.

[Detection of malignant focal hepatic lesions. Comparison of ultrasonography, computerized tomography during arterial portography, delayed computerized tomography and magnetic resonance imaging]

AIMS

This study was performed to compare the sensitivity of ultrasonography, computerized tomography during arterial portography, delayed computerized tomography, and magnetic resonance imaging to detect focal liver lesions. Forty three patients with primary or secondary malignant liver lesions were studied prior to surgical intervention.

METHODS

The results of the imaging studies were compared with intraoperative examination of the liver, intraoperative ultrasonography and pathology results (29 patients). In the non-operated (14 patients) group, we compared the number of lesions detected by each technique.

RESULTS

One hundred and forty six lesions were detected. There was 84% sensitivity with computerized tomography during arterial portography, 61.3% with delayed scan, 63.3% with magnetic resonance imaging and 51% with ultrasonography in operated patients. In patients who did not undergo surgery, magnetic resonance imaging was more sensitive in detecting lesions.

CONCLUSIONS

In operated and non-operated patients series, CT during arterial portography had the highest sensitivity, but magnetic resonance imaging had the most consistent overall results.

Evaluation of hemagglutinin protein-specific immunoglobulin M for diagnosis of measles by an enzyme-linked immunosorbent assay based on recombinant protein produced in a high-efficiency mammalian expression system

Recombinant hemagglutinin (H) of the measles virus (MV) expressed in a mammalian high-expression system based on the Semliki Forest virus replicon was used in an enzyme-linked immunosorbent assay (ELISA) for the detection of specific immunoglobulin M (IgM) and IgG in patients with acute-phase measles. One hundred twelve serum specimens from 70 patients with measles were analyzed. Case definition was based on a commercial IgM ELISA that utilizes MV-infected cells (MV-ELISA) (Enzygnost; Behring Diagnostics); the clinical criteria of the Centers for Disease Control and Prevention (Atlanta, Ga.); and/or the increase in hemagglutinin test titers, neutralization test titers, and levels of MV-specific IgG whenever paired sera were available. The initial time courses of the IgM signal after the onset of rash are similar in the H- and MV-ELISAs. On days 0 to 19, both ELISAs detected IgM in 67 of 68 (98.5%) sera. Average maximal levels of IgM seem to persist, however, about 10 days longer in the MV-ELISA (up to day 25) than in the H-ELISA (day 15). From days 20 to 29 and 30 to 59, the H-ELISA detected only 64.3 (9 of 14) and 19.2% (5 of 26), respectively, of sera that were IgM positive by MV-ELISA. At least up to day 30, the performance of the H-ELISA seemed to be similar to that reported for commercial ELISAs based on whole MV. Our results demonstrate that MV H-specific IgM can be used to diagnose most measles cases from a single serum specimen collected within 19 days after the onset of rash and that the recombinant protein used in this study is suitable for this purpose.

Differential amygdala activation in schizophrenia during sadness

Several studies have reported impaired emotion processing in schizophrenic patients. However, the corresponding functional cerebral correlates of such impairment have not been fully understood, leaving the neurobiological basis of their affective symptoms unknown. Functional magnetic resonance imaging (fMRI) was utilized to examine brain activity in subcortical and cortical regions of 13 medicated male schizophrenic patients and 13 matched healthy controls during happy and sad mood induction. Results show brain activity in the amygdala of normal controls during negative affect, which is in line with previous neuroimaging findings. Unlike controls, schizophrenic patients have not demonstrated amygdala activation during sadness despite matched ratings to normal controls indicating a similar negative affect. Recognizing that structural abnormalities exist in the amygdala of schizophrenic patients, our results provide new evidence of functional abnormalities in the limbic system.

Fast genotypic detection of drug resistance mutations in the HIV-1 reverse transcriptase gene of treatment-naive patients

OBJECTIVES

This study was performed to assess the frequency of drug resistance mutations in treatment-naive HIV-1-infected patients.

STUDY DESIGN/METHODS

Frozen plasma samples from 135 treatment-naive HIV-infected adults were available from the first time the patients were seen for their infection in our center between 1992 and 1997. A rapid genotypic assay based on reverse DNA hybridization (LiPA HIV-1 RT, Murex, London, U.K.) was used to study substitutions at reverse transcriptase (RT) codons 41, 69, 70, 74, 184, and 215. Additionally, a selective polymerase chain reaction (PCR) for the multiple dideoxynucleoside resistance (MddNR) mutation Q151M was performed.

RESULTS

16 patients (12%) harbored virus with one or more drug resistance mutations. The prevalence of patients with drug-resistant virus was 0% in 1992, 17% in 1993, 0% in 1994 (only 6 samples tested), 18% in 1995, 14% in 1996, and 9% in 1997. Mutation K70R (resistance to zidovudine) was found in 8 patients, M41L (resistance to zidovudine) in 5 patients, M184V/I (resistance to ddI/ddC/3TC) in 2 patients, and T215Y/F (resistance to zidovudine) in 4 patients. All samples were wild type at codons 69 (ddC), 74 (ddI), and 151 (MddNR).

CONCLUSIONS

Virus strains containing drug resistance mutations are now found in about 1 of 10 treatment-naive HIV-1-seropositive patients in Luxembourg. We believe that testing for drug-resistant virus before starting treatment should be recommended and will help to improve the selection of the most effective antiretroviral treatment. We also suggest the need for an international surveillance program on HIV drug resistance in treatment-naive patients.