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(1992). Untersuchungen der hepatischen Entgiftungskapazitat klinisch gesunder Kindergartenkinder mit 15N-in-vivo-Tests. Isotopenpraxis Isotopes in Environmental and Health Studies: Vol. 28, No. 1, pp. 38-39.

(1992). Messung des Energieumsatzes in biologischen Systemen mit stabilen Isotopen. Isotopenpraxis Isotopes in Environmental and Health Studies: Vol. 28, No. 1, pp. 43-44.

The level scheme of 137 Nd has been investigated by methods of in-beam γ-ray and conversion electron spectroscopy as well as by observing the γ-transitions following the β-decay of 137 Pm . We measured γ-ray and conversion electron singles spectra, γγ coincidences and angular distributions of prompt γ-rays and conversion electrons. The experimental data result in a detailed level scheme of 137 Nd and allow the assignment of spin and parity to the β-decaying level in 137 Pm , i.e. I π = 11 2 − . Members of a disturbed rotational band based on the 11 2 − isomeric state of 137 Nd and populated by prompt γ-transitions (high spin levels) as well as by the β-transitions of 137 Pm (low spin levels) are identified. The negative parity levels are discussed in a particle-plus-rotator model with Coriolis coupling. Though the analysis results in evidence for a weak prolate deformation of 137m Nd , a quantitative description of the observed level scheme is not achieved. There are features which suggest that a γ-deformation of the core has to be taken into account.

Die vorliegende Arbeit vergleicht den Einfluβ von zwei Aminosäurenlösungen auf den posttraumatischen Proteinstoffwechsel durch Bestimmung der Stickstoffbilanz, der 15N-Elimination, der Gesamt-körperproteinsynthese und der Verwertung des zugeführten Stick-stoffs unter Verwendung von Schweinen als Versuchstiere. Die Proteinsynthese und die Stickstoffverwertung wurden mit Hilfe der 15N-Tracertechnik bei Nutzung mathematischer Modellvorstellungen ermittelt. Die nicht operierten Kontrolltiere wiesen bei Infusion einer Lösung mit einem herkömmlichen Aminosäurenmuster (Lösung A) eine geringere Stickstoffausscheidung im Urin, eine günstigere Stickstoffbilanz, eine höhere 15N-Retention, eine bessere Gesamtkörper-proteinsynthese und Verwertung der infundierten Aminosäuren auf, verglichen mit den operierten Tieren, denen entweder Lösung A oder eine andere Aminosäurenlösung (Lösung B) verabreicht wurden. Die Gegenüberstellung der postoperativen Daten zeigt, daβ bei Vergleich der Lösung A mit Lösung B, deren Aminosäurenzusammensetzung den posttraumatisch veränderten Plasmaaminosäurenmetabolismus berücksichtigt, Lösung B die besseren Ergebnisse hinsichtlich der 15N-Retention, aber auch der Gesamtkörperproteinsynthese und der Stickstoffverwertung aufweist.

In der Arbeit wird untersucht, unter welchen analytischen Bedingungen eine quantitative Sticksoffbestimmung mit dem 15 N-Analysator NA-5A mittels Isotopenverdunnung durchzufuhren ist. Es wird auf die Berechnung der N-Menge, die Abschatzung des maximalen Fehlers unter den speziellen Verhāltnissen der 15N-Analysator-Anwendung und die Auswertungsverfahren naher eingegangen. Testanalysen an unterschiedlich markierten Modell-Losungen, bestehendaus Ammonium-, Harnstoff- und Aminosaurestickstoff, ergaben gute Ubereinstimmung mit den vorgegebenen Werten. Das Verfahren wurde zur N-Bestimmung von biologish-medizinischem Material eingesetzt. Ein Arbeitsschema zur quantitativan Bestimmung von Ammonium-N, Harnstoff-N und Gesamt-N direkt in Harn wird mitgeteilt.

Es wird eine standardisierte 15N-Tracermethode für die Beurteilung des Stickstoff- bzw. Proteinstoffwechsels des gesunden und pathologisch veränderten Organismus beschrieben. Diese isotopentechnische Methode eignet sich für die Anwendung in der klinischen Forschung und Praxis. Sie umfaβt folgende Arbeitsschritte: die klinische Vorbereitung des Patienten/Probanden mit Hilfe eines standardisierten Ernährungsregimes, die Traceradministration (einmalig oral) und die Probensammlung (Urin, Blut), die 15N-Tracertechnik (Probenchemie, emissionsspektrometrische Isotopenanalyse) und die mathematische Auswertung der 15N-Tracerdaten.

Gamma rays and conversion electrons have been measured following thermal neutron capture in 113 Cd using the crystal spectrometers GAMS and the β-spectrometer BILL at the High Flux Reactor of the ILL at Grenoble. Primary γ-rays following thermal and average resonance neutron capture at E n = 2 keV and 24 keV were recorded at the High Flux Beam Reactor at the Brookhaven National Laboratory. The 113 Cd(d, p) 114 Cd reaction was studied with the Q3D spectrograph at the Munich tandem accelerator. Combining all these experimental results an almost complete level scheme of 114 Cd was constructed up to 3.3 MeV including 48 excited levels with spin and parity information. The level scheme is discussed in terms of particle-hole excitations across the Z = 50 closed shell coupled to collective states, as well as in an interacting boson configuration mixing scheme.

Klinische Untersuchungen zum menschlichen Stickstoffmetabolismus, die unter Verwendung des stabilen Stickstoffisotops 15N durchgefuhrt wurden, werden mit Hilfe eines 3-Compartmentmodells ausgewertet und interpretiert. Moglichkeiten zur Erweiterung dieses Modells werden diskutiert, und durch Computerstudien wird die Aussagekraft der aus Modellen gewonnenen Resultate uberpruft.

Wahrend die Anwendung von radioaktiven Nukliden in der Medizin schon seit vielen Jahren zum Standard der spezialisierten Diagnostik zahlt, ist die medizinische Anwendung stabiler Isotope erst im letzten Jahrzehnt verstarkt in Erscheinung getreten. In einem Uberblick werden die Voraussetzungen fur den Einsatz stabiler Isotope am Menschen sowie die Schwerpunkte der medizinischen Einsatzgebiete besprochen. Auf Beitrage der DDR zu dieser international in beachtlicher Entwicklung befindlichen Forschungsrichtung wird dabei hingewiesen.

A high-resolution study of the 76Se(n, γ) reaction was carried out with curved-crystal and pair spectrometers and conversion electrons were measured following slow-neutron capture. The resulting data yield very precise level energies and spin and parity assignments for most of the levels. The neutron separation energy of 77Se was measured as 7418.85 ± 0.07 keV. The experimental data were compared with theoretical results for the level energies in 77Se and the E2, M1 and E1 branching ratios obtained from the SU(6) particle-vibration model (PTQM). We used 76Se as a slightly perturbed SU(5) vibrational core and the particle-vibration interaction strengths from the PTQM calculation for 75Se. In this frame there is evidence for a Δn = 2 term in the E2 operator. This term has not been included so far in TQM and IBM calculations.

The stable nitrogen isotope 15N is being increasingly used in life sciences. Problems of following the course of nitrogen in digestion/absorption studies of nutrients, their intermediary metabolism and dynamic behaviour can be readily dealt with using nitrogen-15. The object of this paper is to discuss some aspects of the isotope analysis of 15N, useful tracer techniques, and theoretical considerations. It is shown that nitrogen balance is a valuable concept for expressing the relationship between the overall nitrogen intake of the body and its nitrogen losses. However, a mere summary of total exchange gives little information of any particular metabolic processes within the body unless these are reflected in the total nitrogen exchange. Feeding trace doses of 15N labelled substances like proteins and amino acids the kinetics of digestion and absorption is indicated by a measurable change of the 15N abundance in serum and urinary nitrogen compounds, i.e. by a significant delay in nitrogen absorption in pa...

Unter Anwendung des stabilen Isotops 15N wurde die Verwertung von Aminosäureninfusionslösung bei Gesunden und bei Patienten im Streß (Zustand nach Cholezystektomie) untersucht. Die Ergebnisse beziehen sich auf Infusionsgeschwindigkeit, Dosierung, Infusionslösung und Glyzin als Tracersubstanz. Es konnte nachgewiesen werden, daß Aminosäuren auch im Streß zur Eiweißsynthese herangezogen werden, wenn auch in geringerem Maße als bei Probanden in ausgeglichenem Stoffwechselzustand. Vom infundierten 15N verblieben 72 bis 77 % bei ausgeglichener Bilanz und 56 bis 58 % bei kataboler Stoffwechsellage im Organismus. Die Harnstoffbildung lief im Streß verstärkt und beschleunigt ab. Die gefundenen Werte passen gut zu den Resultaten früherer Zufuhr-Bilanz-Versuche an Patienten in verschiedenen Streßlagen. Sie gestatten Aussagen über die Effektivität der parenteralen Aminosäurenzufuhr im Streß.

A spectrometer to measure the angular distribution of conversion electrons in charged particle induced reactions is described. The spectrometer consists of a magnetic filter built with small permanent magnets and s Si(Li) detector. The parameters of the instrument are discussed and attenuation factors due to the finite solid angles are evaluated. Spectra of conversion electrons following the reaction 169 Tm(d, x n) and 182 Os(d, x n) at an incident deuteron energy of E d =52 MeV taken at different angles are shown. Angular distribution coefficients are calculated and the evaluation of the data in the framework of the formalism developed in part I is demonstrated.

The case of a 30-year-old woman with intra- and extrahepatic biliary dilatations (Caroli's disease) is reported. The features of the disease and its differential diagnosis are discussed. Special reference is given to the diagnostic approach by endoscopic retrograde cholangiography and to treatment with Chenodeoxy-cholicacid.

Excited levels of143Eu have been investigated by nuclear spectroscopy methods. We measured γ-rays and conversion electron singles spectra as well asγγ-coincidences from mass separated143mGd sources (108 s) prepared after the irradiation of144Sm with 78 MeVα-particles. In addition in-beam data were obtained by measuringγ-ray singles spectra, angular distributions andγγ-coincidences, following the144Sm(α, 4n+ p, γ) reaction. A level scheme for143Eu comprising 19 levels is proposed, spin assignments or at least restrictions are given. The deduced experimental level scheme can be reproduced semiquantitatively by a generalized decoupling model which takes into account an asymmetric deformation of the core and a variable moment of inertia. Additionally, the results are discussed in the limit of the weak coupling model.

The 15N tracer technique teas used to investigate liver specific reactions (urea and hippurate synthesis) for studying the metabolism in the healthy and damaged pig liver. After [15N]ammonium chloride administration the tracer distribution on non-protein compounds of serum and urine was followed. Blood sampling before and after the liver passage made possible a direct analysis of the [15N]ammonium metabolism. The thioacctamide induced liver damage was used as a model for an acute liver intoxication. In our studies the capacity for urea synthesis was not influenced by means of this noxious substance, but the metabolism of amino acids and the hippuric acid. The considerable depressed excretion of [15N] hippurate might be a suitable indicator of a liver disfunction.

Orange-type configurations of permanent magnets around a central absorber serve with a Si solid-state detector as compact and versatile multi-channel spectrometers for conversion electrons. The spectrometers can separate electrons from dominating backgrounds of α, β+, γ and δ radiation with good filtering properties over broad and adjustable energy ranges from below 0.1 to above 2.5 MeV. Absolute detection efficiencies can be more than 7% at the lower and more than 3% at the higher energies. They allow decay studies with weak sources (nCi range) of short-lived activities. Energy resolutions of 2–3 keV (fwhm at 1 MeV) and time resolutions of 8 ns have been achieved. Overall dimensions of magnets plus source and detector are of the order of 10 cm. Examples of decay studies contain among others a weak E4 crossover transition and some recently discovered E0 transitions. In-beam measurements with cyclotron beams appear possible, though proper precautions against intense δ radiation are sometimes necessary. Modified for small angular acceptance, a mini-orange device has been used for in-beam observation of angular distributions of conversion electrons.

The 'sump syndrome' is a rare, late complication of choledochoenterostomies. We observed 13 patients with this syndrome. The clinical features included recurrent cholangitis, liver abscesses, and recurrent pancreatitis. Five patients were treated by surgery, eight patients endoscopically. Reviewing an average follow up period of 22 months (range 6-60) after therapeutic endoscopy and 57 months (range 1-126) after different surgical procedures, we conclude that endoscopic sphincterotomy with removal of the debris is as efficient a therapy of the 'sump syndrome' as surgical sphincteroplasty and entails a smaller risk for the patient. We therefore advocate that endoscopic papillotomy should first be tried in all cases of 'sump syndrome' in the absence of suprapapillary stricture of the bile ducts.

Im Rahmen dieser Studie haben wir die Utilisation einmalig oral applizierten 15N-Glyzins an insgesamt 7 Patienten in der Rekonvaleszenz untersucht. In regelmäβigen Abständen wurden Gesamt-N, Harn-stoff-N und Ammoniak-N sowie deren relative 15N-Häufigkeit im Urin untersucht. Wir erhielten folgende Ergebnisse: Der Ammoniakpeak fand sich 25 Minuten früher als der Harnstoffgipfel. Die kumulative 15N-Aus-scheidung betrug nach 24 Stunden 25 % und nach 6 Tagen 34,4 % der Zufuhr. Nach 12 Stunden waren bereits 53 % der nach 6 Tagen insgesamt eliminierten Menge ausgeschieden. Der Anteil des Harn-stoff-15N am Gesamt-15N betrug 24 Stunden nach Applikation 80 %, der des Ammoniak-15N 2,8 %. Weiterhin konnten Korrelationen zwischen Stickstoffzufuhr minus -ausfuhr als Maβ der Bilanz und kumulativer Ausscheidung von 15N-Harnstoff nachgewiesen werden. Bei Negativierung der Bilanz erhöhten sich kumulative Ausscheidung sowie Anteil des Harnstoffs am Gesamtstickstoff und relative Elimination nach 12 Stunden gegenüber 144 Stunden. Daraus kann geschlossen werden, daβ sich bei kataboler Stoffwechsellage die Metabolisierung von Glyzin zu Harnstoff erhöht. Gleichzeitig wird dieser Prozeβ beschleunigt. Das gewählte Modell scheint geeignet, auf relativ einfache Weise einen Einblick in die Stoffwechselsituation zu erhalten.

Zwischen wasirigen Harnstofflosungen und stark sauren Kationenaustauscher-Harzen vom Typ der Polystyrolsulfon-sauren stellt sich ein Fest-FIussig-Phasenverteilungsgleichgewicht mit einem Isotopiceffekt des Stickstoffs und Kohlenstoffs im Harnstoff ein. Die [13C, 15N] Harnstoff-Molekule werden bevorzugt an die Austauschermatrix gebunden. Die elementaren Trennfaktoren fur die 15N- und fur die 13C-Anreichernng werden zu 1,004 bestimmt. Durch saulenchromatographische Trennung an Dowex 50 WX8 wird die praaparativc Darstellung doppelt markierten Harnstoffs moglich.

Folgende Untersuchungen an Rattenorganen waren durch 15N-NMR-Messungen moglich: – Verteilung von in vivo applizierten 15N-markierten Verbindungen auf verschiedene Organe in Abhangigkeit von der Einwirkungszeit; – Ermittlung der Biotransformationskinetik von [15N]Glycin als Maβ fur die fortdauernde metabolische Aktivitat der entnommenen Leber; – Nachweis intermediar auftretender Metabolite des Glycins. Es wurden [15N2]Harnstoff und [15N]Glycin injiziert. Aus den Ergebnissen folgt, daβ die 15N-NMR-Spektroskopie in Verbindung mit der traditionellen 15N-Analyse eine neue Moglichkeit zur Verfolgung des Stickstoffstoffwechscls von Pflanze, Tier und Mensch am intakten Organismus eroffnet. Using 15N NMR measurements functional studies in rat organs were possible and could be demonstrated with the following examples: – 15N distributions to various rat organs depending on the effective time of the injected compounds; – measurement of biotransformation kinetics of [15NJglycine showing the continued metabolic activit...

The γ and e − spectra following thermal neutron capture in 74 Se were studied with curved-crystal, β, and pair spectrometers. Precise energies have been obtained for the transitions and levels at low energies. Two primary E2 transitions were found. The neutron separation energy for 75 Se was determined as 8027.6 keV. Precise γ-energies following the electron capture decay of 75 Se were also measured, resulting in precise level energies in 75 As. The calculation of the energy levels in 75 Se has been performed in the SU(6) particle-vibrational model (PTQM) and 27 theoretical states have been tentatively assigned to the experimental levels. The spectrum of the core nucleus 74 Se has been calculated in the SU(6) quadrupolephonon model (TQM). The structure of theoretical states, the relation to SU(3) and SU(5) limits, and potential energy surface are discussed. The E2, M1 and E1 transitions have been calculated in PTQM and compared to the experiment. Also, an overview is presented of theoretical explanations of the I = j , j −1, j −2 anomalous triplet emphasizing the rule with shell-model classification corrected for quadrupole phonons.

RNA fractions rich in immunoglobulin light (L)-chain mRNA were isolated from mouse myeloma MOPC 41 by procedures previously described, and chemically labeled with 125I. These RNA fractions were hybridized with MOPC 41 DNA under conditions of DNA excess. Hybridization conditions were chosen under which the entire sequence of the L-chain mRNA probe, thus including the variable region, remains available for hybridization throughout the reaction. The hybridization (C0t) curve showed double transition kinetics, with one component corresponding to about 250 gene copies and the other to about two to four copies. In contrast, when MOPC 41 L-chain mRNA was further purified as a single band by gel elecptrophoresis in 99% formamide, the hybridization curve showed only a single transition, corresponding to about two to four genes, with the disappearance of the "reiterated" component. That component resulted therefore from contaminating RNA species. The data indicate that no reiteration can be detected by RNase or by hydroxylapatite for the genes corresponding to the entire sequence of MOPC 41 L-chain mRNA, including the untranslated segments, within the limits of detectability of short reiterated segments. It thus appears that there is only one or very few genes corresponding to the 41 L-chain variable region "subgroup" in MOPC 41 DNA. The possibility that the variable genes of plasmocytes might result frm a combination of several nonreiterated germline genes is discussed.

Mit Hilfe der in dieser Arbeit vorgestellten 15N-Tracermethodik kann der Einfluß parenteraler L-Aminosäurenzufuhr auf den Proteinstoff-wechsel des Gesamtorganismus untersucht werden. Gleichzeitig läßt sich die Verwertung des parenteral zugeführten Stickstoffs quantitativ bestimmen. Die Berechnung der Proteinsynthesegeschwindigkeit, unter der Voraussetzung, daß der NPN-Pool über den gesamten Versuchszeitraum weitestgehend konstant bleibt, erfolgt auf der Grundlage graphischer Verfahren. Diese Verfahren ergeben sich aus einem mathematischen Formalismus, der sich aus dem 3-Pool-Modell ableiten läßt. Die Ermittlung der Werte basiert auf der 15Elimination im Urin nach 24 h intravenöser Infusion 15N-markierter Aminosäurenlösungen (Endproduktmethode). Es werden 3 graphische Verfahren beschrieben, bei denen sogenannte Plateauwerte der kumulativen 15N-Exzeßmenge nach 96 h (Plateaumethode A) bzw. der 15N-Exzeßhäufigkeit nach 24 h (Plateaumethode B) sowie der Anstiegswinkel der kumulativen 15Exzeßmenge innerhalb 24 h (Anstiegsmethode) genutzt werden. Diese Verfahren ermöglichen die Bewertung u.a. ernährungstherapeutischer Konzepte.

The 9th observation of esophageal intramural diverticulosis is reported. The findings are compared with those of former publications. Clinically dysphagia is a leading symptom. Suction biopsy proved diverticulosis being the correct interpretation for radiological findings. The etiology is discussed. The change between symptom-free intervals with diverticulosis only and episods of dysphagia by secondary inflammation (reflux esophagitis, moniliasis, stenosis) stresses the importance of such secondary complications. These inflammations can hide the real diagnosis for a long time. The radiological findings are the key for diagnosis, however, they can be very small for years. During this period a diagnosis can only be achieved by knowledge of the disease and the skilful search for early symptoms.

In der Arbeit werden theoretische Grundlagen der Untersuchung des menschlichen Stickstoffmetabolismus unter Verwendung des stabilen Stickstoffisotops 15N sowie methodische Probleme der Auswertung solcher Untersuchungen dargestellt. Als allgemeines mathematisches Modell zur Untersuchung von Synthese-, Abbau-, Transport- und Eliminationsprozessen im Organismus wird die Compartmentlheorie erortert, zur Auswerlung von experimentell gewonnenen Daten dient die nichtlineare Ausgleichsrechnung. Anhand eines 3-Compartment-Modells wird untersucht, in welcher Weise der allgemeine Formalismus auf Probleme des Stickstoffmetabolismus angewendet werden kann und welche Probleme bei der Verknupfung von Theorie und Experiment auftreten.

The application of stable isotopes creates further possibilities for our understanding of the metabolism. New concepts especially for non-invasive diagnostic procedures could be developed. An important step in our research program was the performing of a 1-year experiment on a volunteer. On the basis of a 10-pool model we received a lot of informations. Based on this knowledge we developed 2 simplified methods for calculating whole body protein turnover. Knowing the problems with whole body protein calculations we intensified our intentions for determining the protein enrichment in organs and isolated cells (hepatocytes), estimating at the same time the precursor pool in the cells. Of special importance was an extensive study, wherein all those 15N-estimations were performed we are able to do up to now. We calculated whole body protein, but especially we studied the enrichment of the cellular protein fractions in hepatocytes, of plasmaproteins, and of the intracellular precursor pool. This study is the base for further tracer investigations.

As previously shown, purified 14S RNA of mouse myeloma MOPC-41 forms a single peak on sucrose gradients and gel electrophoresis and codes for a single polypeptide chain, the immunoglobulin light chain produced by the same myeloma in vivo . This 14S mRNA was used for the enzymatic synthesis of DNA (cDNA) which is complementary to the RNA template. A DNA fraction was isolated which has an average size of 300 nucleotides. Kinetic studies of the hybridization of the 14S RNA with the cDNA indicate that about 40% of the RNA consists of a single RNA sequence. From the size of the cDNA fraction and from the direction of DNA synthesis, it can be concluded that the cDNA includes the sequence complementary to the constant region of light chain mRNA. This radioactive cDNA was used for DNA·DNA reannealing experiments with unlabeled DNA from mouse liver or myeloma tumor in 3 × 10 6 -fold excess. This allowed the determination of the number of copies in the mouse genome of those sequences represented in the cDNA. The data show no significant reiteration in either liver or myeloma DNA and suggest that the gene coding for the constant part of immunoglobins is present in the haploid genome in one to five copies. Furthermore, this gene is not “amplified” in nuclear DNA of myeloma plasmocytes.

A simple, noninvasive test is proposed to measure the activity of the hepatocellular monooxygenase system in vivo. Elimination rates of the stable isotope 15N are measured in urine after an oral dose of the 15N-labeled phenacetin homologue [15N]methacetin. Different forms of obtaining and expressing results are investigated in order to determine optimum methodology and differentiation for clinical application in pediatrics. The best discriminating power and reliability of results are seen with the measurement of 15N elimination half-life. For follow-up, a more easily measured parameter--eliminated dose over 9 h--is sufficient. In the latter case, only total nitrogen and 15N contents of a collective urine sample are measured.

Auf der Grundlage des Internationalen Einheitensystems (SI) und der jungsten IUPAC-Richtlinien zur Symbolik und Terminologie fur physikalisch-chemische Groβen und Einheiten wird ein Vorschlag unterbreitet, wie die in der Isotopenstochiometrie (z. B. im Rahmen der Isotopenverdunnungstechnik) benotigten Groβen und Einheiten eindeutig und einheitlich bezeichnet und definiert werden sollten. Die enge Verwandtschaft der Isotopenstochiometrie mit der klassischen Stochiometrie wird dabei verdeutlicht.

BALB/c mice immunized with phosphocholine-conjugated keyhole limpet hemocyanin respond with two major groups of antibodies that differ with respect to fine specificity and idiotype. Group I antibodies predominantly bear the T15 idiotype, and show appreciable affinity for the haptens PC and nitrophenyl PC (NPPC), whereas group II antibodies have appreciable affinity for NPPC only and are T15 idiotype negative. Previous studies indicated that group II binding characteristics may derive from the use of novel V gene segments not observed in group I antibodies. To determine the nature of VH gene usage in the group II antibody response, we examined the VH region of a prototype group II hybridoma, PCG1-1. The nucleotide sequence obtained from the VDJ region indicates that PCG1-1 utilizes a VH gene not observed in the group I response, one that belongs to the Q52 VH family. The PCG1-1 VH nucleotide sequence shares 97% identity with the myeloma M141 VH gene. In addition, PCG1-1 utilizes a D segment most closely related to DSP2.6 rearranged to JH-3. These data indicate that M141, a VH gene not seen in group I anti-PC antibodies is utilized by PCG1-1 to generate a PC-protein-binding group II antibody. PCG1-1 was previously shown to express the V kappa 1-3 light chain, a characteristic shared by several group II hybridomas. Furthermore, here we examined the VH gene rearrangements in four lambda 1-bearing group II hybridomas that share a common JH rearrangement with PCG1-1 by Southern blot analysis. A VH-specific probe that detects M141 VH rearrangements revealed that all four lambda 1 hybridomas as well as PCG1-1 share an identical VH gene rearrangement to JH-3. Thus the M141 VH gene product is able to utilize two distinct light chains to generate group II-like combining sites.

The level scheme of 135 Pr has been investigated by means of off-beam γ-ray and conversion electron measurements as well as by methods of in-beam γ-spectroscopy. We measured γ-ray and conversion electron singles spectra, off-beam and in-beam γγ coincidences and γ-angular distributions. From the experimental data a detailed scheme of 22 excited levels for 135 Pr has been constructed. In addition to members of the decoupled band based on the 11 2 − state six further negative parity states were identified. These states are strongly populated in the β-decay of a 9 2 isomer in the parent nucleus 135 Nd. A comparison of all the negative parity states with predictions of the alignment coupling model showed a nearly quantitative agreement, if softness of the core is taken into account. In this case, a prolate deformation with a deformation parameter β ≈ 0.13 was obtained for the 11 2 − isomer in 135 Pr.

The mRNA coding for epsilon-heavy chain and kappa-light chain have been highly enriched from a rat IgE-producing myeloma, IR-162. Based on denaturing gel analyses, the 20 S epsilon-heavy chain mRNA has an estimated molecular weight of 850,000, equivalent to about 2500 nucleotides. The 14S rat kappa-light chain mRNA has an estimated molecular weight of 410,000, equivalent to about 1200 nucleotides. Only about two-thirds of the length of these mature cytoplasmic rat mRNA code for protein. The 20 S mRNA stimulates the in vitro synthesis of a single major serologically related protein which is large enough to be epsilon-heavy chain. It is unglycosylated and has an apparent molecular weight of about 62,000. The in vivo unglycosylated epsilon-heavy chain, obtained in the presence of tunicamycin, has an apparent molecular weight of about 59,000, compared with about 76,000 for the glycosylated heavy chain of the secreted rat IgE. Therefore, the in vitro synthesized epsilon-heavy chain protein is about Mr = 3000 larger than the in vivo unglycosylated epsilon-heavy chain, equivalent to about 25 extra amino acids. This is consistent with the synthesis of an epsilon-heavy chain putative precursor. Likewise, the 14 S mRNA stimulates the in vitro synthesis of a single putative precursor protein, which is serologically related to kappa chain, is unglycosylated, and is about an extra 20 amino acids. This is the first report on the physical and biological properties of an epsilon-heavy chain mRNA, as well as any rat immunoglobulin mRNA.

The 0+ to 41+ hexadecapole transitions in 60Ni and 140Ce have been investigated experimentally by means of alpha -particle scattering as well as by the spectroscopy of the electromagnetic decay of the 41+ states. In the case of 60Ni an upper limit of 1*10-7 was found for the branching of the E4 and E2 cascade decay of the 41+ state by conversion electron spectroscopy. It corresponds to an enhancement factor G4

Chloromethyl phthalimide, oxymethyl phthalimide, and phthalimide are absorbed by the albino rat at a comparatively high rate. Only phthalimide, the metabolic product, will be recordable from fetuses, following oral administration of chloromethyl phthalimide and oxymethyl phthalimide to pregnant rats. Those findings, in conjunction with metabolic studies applied to fetuses isolated by caesarian section, appear to suggest the occurrence of an intensive metabolism in fetal tissue. Certain differences established between results of thin-layer chromatography, on the one hand, and 15N studies, on the other, are likely to support the assumption that phthalimide is further metabolised by splitting the imide ring yielding phthalamic acid.

The pulseheight, X, delivered in surface barrier detectors by incoming fission fragments of given energy, E, and mass, M, has been studied. Fragments separated as to energy and mass from the 235U(n, f) reaction induced by thermal neutrons were available from the Lohengrin spectrometer of the ILL. The energies on Lohengrin were calibrated by a time-of-flight technique. It could be shown that for the mass and energy ranges of unslowed fragments encountered in nuclear fission there is a linear relationship between E and X for any fixed M, and similarly a linear relationship holds between E and M for any fixed X. The calibration equation, therefore, reads E = (a + a′M) X + b + b′M with a through b′ being constants characterizing the detector. In parallel to the above measurements, the pulseheight spectra from a 252Cf(sf) source were taken. The pulseheights X = PL and X = PH for the light and heavy fragment peaks of this spectrum were determined by a fitting procedure with Gaussians. Several detectors having been tested, it appears that at least for detectors of the same brand, a universal calibration scheme can be set up which correlates the detector constants a through b′ to the Cf spectrum parameters PL and PH. The accuracy of this calibration is sufficient for most practical purposes. The above calibration method has been put forward and in general use since many years [1]. However, the revised constants of the present investigation yield kinetic energies of fission fragments which are lower by about 1–2%. These energies are in excellent agreement with recent independent measurements of the kinetic energy release in fission. Along with the calibration the energy resolution of surface barrier detectors has been studied as a function of bias voltage on the detector and mass or energy of incoming ions.