Über die Verwertung von NPN **-Verbindungen für die Synthese von Milch- und Körpereiweiß beim laktierenden Rind

Die im Rahmen umfassenderer Untersuchungen5 über den Stickstoff-Stoffwechsel laktierender Rinder erhaltenen experimentellen Ergebnisse über die Zufütterung von Harnstoff-[15N] werden einer mathematischen Analyse unterworfen. Den Berechnungen liegt ein schon in früheren Arbeiten beschriebenes Modell des Stickstoff-Stoffwechsels laktierender Wiederkäuer zugrunde. Die in dem Modell vorkommenden Stickstoffströme und Pool-Größen sind bei Harnstoffzufütterung von der gleichen Größenordnung wie bei Zufütterung von Ammoniumhydrogencarbonat 1 bzw. Ammonhydrogensulfat 4.

Bei anhaltender Zufütterung stabilisotop markierter Stickstoffverbindungen würden sich echte stationäre 15N-Häufigkeiten in Milch, Harn und Kot einstellen, die sowohl (auf indirektem Wege) experimentell bestimmt als auch aus dem Modell berechnet werden können. In der Übereinstimmung zwischen den auf beiden Wegen berechneten stationären 15N-Häufigkeiten kann ein weiterer Beweis für die Gültigkeit des Modells gesehen werden.

Rapid and sensitive detection of Pseudomonas aeruginosa in chlorinated water and aerosols targeting gyrB gene using real-time PCR

AIMS

For the rapid detection of Pseudomonas aeruginosa from chlorinated water and aerosols, gyrB gene-based real-time PCR assay was developed and investigated.

METHODS AND RESULTS

Two novel primer sets (pa722F/746MGB/899R and pa722F/746MGB/788R) were designed using the most updated 611 Pseudomonas and 748 other bacterial gyrB genes for achieving high specificity. Their specificity showed 100% accuracy when tested with various strains including clinical isolates from cystic fibrosis patients. The assay was tested with Ps. aeruginosa-containing chlorinated water and aerosols to simulate the waterborne and airborne transmission routes (detection limit 3·3 × 10² CFU per PCR-2·3 × 10³ CFU per PCR). No chlorine interference in real-time PCR was observed at drinking water level (c. 1 mg l⁻¹), but high level of chorine (12 mg l⁻¹) interfered the assay, and thus neutralization was needed. Pseudomonas aeruginosa in aerosol was successfully detected after capturing with gelatin filters with minimum 2 min of sampling time when the initial concentration of 10⁴ CFU ml⁻¹ bacteria existed in the nebulizer.

CONCLUSIONS

A highly specific and rapid assay (2-3 h) was developed by targeting gyrB gene for the detection of Ps. aeruginosa in chlorinated water and aerosols, combined with optimized sample collection methods and sample processing, so the direct DNA extraction from either water or aerosol was possible while achieving the desired sensitivity of the method.

SIGNIFICANCE AND IMPACT OF THE STUDY

  The new assay can provide timely and accurate risk assessment to prevent Ps. aeruginosa exposure from water and aerosol, resulting in reduced disease burden, especially among immune-compromised and susceptible individuals. This approach can be easily utilized as a platform technology for the detection of other types of micro-organisms, especially for those that are transmitted via water and aerosol routes, such as Legionella pneumophila.

Adherence and persistence in patients with postmenopausal osteoporosis treated with raloxifene

OBJECTIVE

A major impediment in osteoporosis care is poor therapeutic adherence. Real-life surveys show that adherence and persistence with oral bisphosphonates decrease to 30-60% within 1 year. The aim of this study was to analyze the adherence and persistence with raloxifene in patients visiting our outpatient clinic.

MATERIAL AND METHODS

A total of 342 patients were evaluated from the conventional osteoporosis practice receiving treatment with raloxifene. Patient self-reporting was combined with the medication possession ratio (MPR) assessed via prescription refill counts. In addition, persistence and other self-reported and patient file-based data were assessed.

RESULTS

The final analysis comprised 300 patients with a mean age of 66.3 years (standard deviation ± 7.2 years). At 6 months 84%, at 12 months 81%, at 24 months 78% and at 36 months 77% of patients were persistent with therapy according to patients' self-reports. If MPR and self-reported data were combined, 56%, 48% and 35% of patients remained on therapy at 12, 24 and 36 months, respectively. The mean duration of therapy was 19 months with a mean MPR of 52.8%. Finally, 31.7% of all patients were classified as adherent. Significant correlation to adherence was found for tolerability and motivational factors.

CONCLUSION

This study revealed that approximately half of the patients treated with raloxifene in regular clinical practice stay on therapy for the first 2 years. Furthermore, the patients do not adhere sufficiently to the recommended dosage, and reduced clinical efficacy in clinical practice is presumable. The reasons for non-adherence comprise tolerability and motivational factors but further investigation is needed.

Comparison of midregional pro-atrial natriuretic peptide with N-terminal pro-B-type natriuretic peptide in the diagnosis of heart failure

OBJECTIVES

The concentration of atrial natriuretic peptide (ANP) in the circulation is approximately 10- to 50- fold higher than B-type natriuretic peptide (BNP). We sought to compare the accuracy of midregional pro-atrial natriuretic peptide (MRproANP) measured with a novel sandwich immunoassay with N-terminal pro-B-type natriuretic peptide (NTproBNP) in the diagnosis of heart failure.

DESIGN

The diagnosis of heart failure was adjudicated by two independent cardiologists using all available clinical data (including BNP levels) in 287 consecutive patients presenting with dyspnoea to the emergency department (ED). MRproANP and NTproBNP levels were determined at presentation in a blinded fashion.

RESULTS

Heart failure was the adjudicated final diagnosis in 154 patients (54%). Median MRproANP was significantly higher in patients with heart failure as compared to patients with other causes of dyspnoea (400 vs. 92 pmol L(-1), P < 0.001). The diagnostic accuracy of MRproANP was very high with an area under the receiver operating characteristic curve of 0.92 and was comparable with that of NTproBNP (0.92, P = 0.791). Moreover, MRproANP provided incremental diagnostic information to BNP and NTproBNP in patients presenting with BNP levels in the grey zone between 100 and 500 pg mL(-1).

CONCLUSION

Midregional pro-atrial natriuretic peptide is as accurate in the diagnosis of heart failure as NTproBNP. MRproANP seems to provide incremental information on top of BNP or NT-proBNP in some subgroups and should be further investigated in other studies.

Isolated Bacterial Meningitis as the Key Syndrome of Infective Endocarditis

BACKGROUND

Bacterial meningitis is an unusual first manifestation but a major complication of infective endocarditis.

PATIENTS AND METHODS

We present three well documented cases of isolated bacterial meningitis in endocarditis. Against this background we review the literature.

RESULTS

All patients presented with bacterial meningitis. Staphylococcus aureus was isolated in blood cultures of all patients, but was found only in the cerebrospinal fluid (CSF) of one patient. The underlying endocarditis was confirmed histologically in all three cases. Two patients recovered completely and one died.

CONCLUSION

An extensive search for endocarditis is recommended in every case of an unusual isolate in bacterial meningitis whether it is isolated from blood or CSF.

Transduction of human MCP-3 by a parvoviral vector induces leukocyte infiltration and reduces growth of human cervical carcinoma cell xenografts

BACKGROUND

The oncosuppressive properties of some autonomous parvoviruses such as H-1 virus, together with their low pathogenicity, make them attractive vectors for tumor-directed gene therapy. Indeed, it was recently shown that these viruses became endowed with an enhanced oncosuppressive activity after they had been engineered to deliver a recognized therapeutic transgene. This prompted us to use a parvoviral vector to analyse the antineoplastic capacity of MCP-3 (monocyte chemotactic protein-3), a CC chemokine which has a broad spectrum of target cells, and can thus be considered to be a promising candidate for cancer treatment.

METHODS

We explored the use of a parvovirus H-1-based vector encoding human MCP-3 for its antitumor potential on human cervical carcinoma cells. HeLa cells were infected in vitro with the recombinant virus hH1/MCP-3 at a low multiplicity [1 replication unit (RU)/cell] and we investigated the effect of parvovirus-mediated MCP-3 transduction on tumor formation and growth upon implantation of HeLa cells in nude mice.

RESULTS

Infection of HeLa cells with hH1/MCP-3 led to secretion of high levels of MCP-3 and to significant retardation of tumor growth in recipient mice, as compared with HeLa cells that were either buffer-treated or infected with a MCP-3-free vector. Tumors from hH1/MCP-3-infected HeLa cells were heavily infiltrated with activated macrophages and showed increased numbers of dendritic cells. In addition, activated natural killer (NK) cells were also recruited into MCP-3-transduced tumors.

CONCLUSION

These observations indicate that parvovirus H-1-transduced MCP-3 is able to exert a significant antitumor activity which is mediated, at least in part, through macrophages and NK cells, under conditions in which activated T cells are lacking.

Detection of Giardia lamblia and Entamoeba histolytica in stool samples by two enzyme immunoassays

Two commercially produced enzyme immunoassays (EIAs) to detect antigens of Giardia lamblia and Entamoeba histolytica in stool specimens were evaluated. A total of 276 stool specimens were collected from patients who presented with various medical complaints in the outpatient clinic of the Department of Infectious Diseases and Tropical Medicine, University of Munich. Every specimen was examined by conventional microscopy and tested by both EIA kits. When microscopy was used as the reference standard, the EIA kit detecting Giardia lamblia showed a sensitivity of 100% and a specificity of 99.6%. The EIA kit detecting Entamoeba histolytica had a sensitivity of 81.8% and a specificity of 99.2%. Both tests showed no cross-reactivity with other intestinal protozoa. Antigen detection by EIA has the potential to become a valuable tool capable of making stool diagnostics more effective, although it should not be considered as a replacement for microscopic examination, since other potential pathogens could otherwise escape detection.

Cell therapy attenuates deleterious ventricular remodeling and improves cardiac performance after myocardial infarction

BACKGROUND

Myocardial infarction (MI) promotes deleterious remodeling of the myocardium, resulting in ventricular dilation and pump dysfunction. We examined whether supplementing infarcted myocardium with skeletal myoblasts would (1) result in viable myoblast implants, (2) attenuate deleterious remodeling, and (3) enhance in vivo and ex vivo contractile performance.

METHODS AND RESULTS

Experimental MI was induced by 1-hour coronary ligation followed by reperfusion in adult male Lewis rats. One week after MI, 10(6) myoblasts were injected directly into the infarct region. Three groups of animals were studied at 3 and 6 weeks after cell therapy: noninfarcted control (control), MI plus sham injection (MI), and MI plus cell injection (MI+cell). In vivo cardiac function was assessed by maximum exercise capacity testing and ex vivo function was determined by pressure-volume curves obtained from isolated, red cell-perfused, balloon-in-left ventricle (LV) hearts. MI and MI+cell hearts had indistinguishable infarct sizes of approximately 30% of the LV. At 3 and 6 weeks after cell therapy, 92% (13 of 14) of MI+cell hearts showed evidence of myoblast graft survival. MI+cell hearts exhibited attenuation of global ventricular dilation and reduced septum-to-free wall diameter compared with MI hearts not receiving cell therapy. Furthermore, cell therapy improved both post-MI in vivo exercise capacity and ex vivo LV systolic pressures.

CONCLUSIONS

Implanted skeletal myoblasts form viable grafts in infarcted myocardium, resulting in enhanced post-MI exercise capacity and contractile function and attenuated ventricular dilation. These data illustrate that syngeneic myoblast implantation after MI improves both in vivo and ex vivo indexes of global ventricular dysfunction and deleterious remodeling and suggests that cellular implantation may be beneficial after MI.

Sequence characteristics, subcellular localization, and substrate specificity of DYRK-related kinases, a novel family of dual specificity protein kinases

DYRK1 is a dual specificity protein kinase presumably involved in brain development. Here we show that the kinase belongs to a new family of protein kinases comprising at least seven mammalian isoforms (DYRK1A, DYRK1B, DYRK1C, DYRK2, DYRK3, DYRK4A, and DYRK4B), the yeast homolog Yak1p, and the Drosophila kinase minibrain (MNB). In rat tissues, DYRK1A is expressed ubiquitously, whereas transcripts for DYRK1B, DYRK2, DYRK3, and DYRK4 were detected predominantly in testes of adult but not prepuberal rats. By fluorescence microscopy and subcellular fractionation, a green fluorescent protein (GFP) fusion protein of DYRK1A was found to accumulate in the nucleus of transfected COS-7 and HEK293 cells, whereas GFP-DYRK2 was predominantly detected in the cytoplasm. DYRK1A exhibited a punctate pattern of GFP fluorescence inside the nucleus and was co-purified with the nuclear matrix. Analysis of GFP-DYRK1A deletion constructs showed that the nuclear localization of DYRK1A was mediated by its nuclear targeting signal (amino acids 105-139) but that its characteristic subnuclear distribution depended on additional N-terminal elements (amino acids 1-104). When expressed in Escherichia coli, DYRK1A, DYRK2, DYRK3, MNB, and Yak1p catalyzed their autophosphorylation on tyrosine residues. The kinases differed in their substrate specificity in that DYRK2 and DYRK3, but not DYRK1A and MNB, catalyzed phosphorylation of histone H2B. The heterogeneity of their subcellular localization and substrate specificity suggests that the kinases are involved in different cellular functions.

Cholinergic modulation of neuronal responses to cholecystokinin in anesthetized rats

The aim of this study was to investigate whether the effects of the neuropeptide cholecystokinin on neuronal firing can be changed by acetylcholine in various structures of the brain. Single unit activity was extracellularly recorded in rats anesthetized with urethane. The neurons were located in several nuclei of the thalamus, the basal ganglia and the cerebral cortex. Neurons responding to the sulfated octapeptide of cholecystokinin (CCK-8S) were mainly activated by the drug [Wilcoxon test (Wt) p < 0.0001, n=113]. Thalamic neurons could also increase the number of burst discharges (Wt p < 0.005, n=39). Iontophoretically administered acetylcholine could reduce the activating effects of CCK-8S on firing and burst discharges. In its presence, even inhibitory effects of CCK-8S predominated (Wt p < 0.0001, n=113). The suppressive action seemed not to depend on the direction of the effect of acetylcholine itself and concerned neurons of all locations studied. Atropine could diminish or block the suppressive action of acetylcholine. In the presence of both drugs, CCK-8S mainly activated the neurons (Wt p < 0.005, n=43). Atropine itself did not significantly change the responses to CCK-8S (Wt p > 0.05). It can be concluded that cholecystokinin may reduce neuronal firing instead of increasing it during activation of the cholinergic system.

Fetal pig neural cells as a restorative therapy for neurodegenerative disease

With proper immunosuppression, interspecies transplantation of porcine as well as other species of neural cells survive, mature, and integrate into the host in a manner which reconstructs much of the appropriate neural circuitry. These transplants have been shown to alleviate many of the symptoms of various disorders of the central nervous system. In this study, we addressed immunological and maturation issues with regards to intracerebral transplantation of fetal porcine neural cells. First, we compared fetal neural xenograft survival in athymic nude rats versus rats immunosuppressed with cyclosporin A and found that there is little discernible difference between porcine grafts in the 2 recipients. We also found that ectopic transplantation of cells isolated from the porcine striatal primordium can survive and develop into grafts composed of both neuronal and glial phenotypes within the rat hippocampus. This fact raises the possibility that cells of a particular neurotransmitter type (e.g., GABAergic cells) developing from the striatal precursor cells can be transplanted outside the striatum of the adult brain and have physiological effects.

Neostriatal neurons of rats can be influenced by cholecystokinin-A receptor agonists

The present study investigated the effects of agonists of the neuropeptide cholecystokinin (CCK) on neostriatal neurons in order to confirm the existence of CCK-A receptors in the rat caudate-putamen. Single unit activity was recorded in rats anaesthetized with urethane. The CCK-A receptor agonists A-71378 (desamino-Tyr(SO3H)-Nle-Gly-Trp-Nle-(N-methyl)Asp-Phe-NH2), and A-71623 (Boc-Trp-Lys(epsilon-N-2-methylphenylamino-carbonyl)-Asp-(N-methyl )Phe-NH2, as well as the CCK-B receptor agonist Suc-CCK-4 (Suc-Trp-(N-methyl)Nle-Asp-Phe-NH2) were iontophoretically administered with multibarrel capillaries. About one-third of the neurons responded to the CCK-A receptor agonists. Excitatory effects predominated. The CCK-B receptor agonist also induced mainly increases in the neuronal firing. Several neurons were affected by both types of agonists. The results suggest that in the rat neostriatum not only CCK-B receptors, but also CCK-A receptors seem to mediate the effects of cholecystokinin.

Effects of cholecystokinin agonists on striatal neurons are reduced by acetylcholine

The present study investigated whether acetylcholine, a transmitter of striatal interneurons, modulates responses of neostriatal neurons to agonists of the neuropeptide cholecystokinin (CCK). Single unit activity was recorded in rats anesthetized with urethane. Acetylcholine and CCK agonists (the CCKA receptor agonists A-71378 and A-71623; the CCKB receptor agonist Suc-CCK-4) were iontophoretically administered alone and in combination. The CCK agonists excited about one third of the neurons. The excitatory effects of both the CCKB and the CCKA receptor agonists were mainly reduced or changed to suppression of activity by acetylcholine (Wilcoxon test p < 0.001). Atropine did not significantly change the neuronal responses to the CCK agonists. The suppressive action of acetylcholine could be diminished by additional administration of atropine. The results suggest that the modulatory action of cholecystokinin does not only depend on the actual state of excitability in striatal neurons, but could be changed by acetylcholine released from interneurons.

Speech-recognizing computers: a written-communication tool for students with learning disabilities?

Students with specific learning disabilities (LD) in written composition may experience difficulties that restrict their ability to demonstrate in writing what they know and can communicate orally. Voice-input technology now allows users to speak into a microphone and have their words appear on a computer screen in a word processing format, ready for revision and editing. This exploratory study reports the efforts of one sixth-grade student to learn to use this technology to assist written communication. The findings suggest that the technology holds promise for students with LD when it is refined to allow less difficulty in using it.

Cholecystokinin excites neostriatal neurons in rats via CCKA or CCKB receptors

The effect of iontophoretically applied cholecystokinin (CCK) on neurons of the neostriatum was studied in rats anaesthetized with urethane. The most frequently observed effect of the sulphated octapeptide (CCK-8S) on striatal neurons was excitation. Spontaneously active neurons responded more often to CCK-8S than quiescent cells. Silent, primarily non-responsive neurons could often be stimulated with CCK-8S using glutamate to induce an ongoing discharge. Thus, 45.8% of the 177 neurons studied changed their discharge rate by more than 30%. Certain CCK receptor antagonists could prevent the effect of CCK-8S, fully or at least partly, in the majority of CCK-responsive neurons. The data suggest that cholecystokinin modulates the firing of active neostriatal neurons via the CCKA or the CCKB receptor type. Furthermore, we compared neuronal responses to glutamate with those recorded during concomitant administration of CCK-8S in order to study the interaction of both transmitters, which may be colocalized in striatal afferents. CCK-8S mainly enhanced the excitatory effect of glutamate on striatal neurons, but in several neurons the response to glutamate was reduced. The CCKB receptor antagonist could prevent CCK-8S from increasing the glutamate-induced activation.

[Prognostic value of hyperkinetic syndrome in children with epilepsy]

In a retrospective study the data of 43 children suffering from epilepsy were analysed. The first epileptic seizure was observed in all patients before the age of 6 years. The relationship between behavioral disturbances with hyperactivity, developmental respectively intellectual test scores, and efficiency of antileptic drug therapy have been investigated. Psychological testings were performed two times, at first after the start of drug therapy, and a second time after a period of 1 year 11 months in average. There were behavioral disturbances with hyperactivity in 20 patients. The epileptic seizures were intractable in 26 patients. The developmental respectively intellectual test scores have decreased to values below 85 in 7 patients with and 3 patients without hyperactivity. There was a decline by more than 10 points of the IQ score between first and second psychological testings in 16 patients with and 4 patients without hyperactivity, respectively in 17 patients with intractable seizures, but in one child only with prompt cessation of epileptic seizures. An increasing retardation of mental development was seen in children with hyperactivity at the start of seizures, in children with intractable seizures, but especially in patients with a combination of intractable seizures and hyperactivity.

Nursing education and organizational commitment: degree versus diploma programs

In the context of calls to change the educational qualifications for entry into the nursing profession, this study attempts to determine whether type of nursing education is associated with nurses' commitment to their employer hospitals. The analysis indicates that even when controlling for personal attributes, personal investments and work attitudes, type of nursing education is related to the level of organizational commitment expressed by nurses. Degree nurses are less committed than diploma nurses. Contrary to prevailing beliefs, the findings also reveal basic similarities between degree and diploma nurses on other measures of professional and work-related attitudes. From an organizational perspective, these similarities call into question the benefit of redefining educational entry standards.