Chemical potential of Aphelandra sp. cell cultures

Six different callus lines and three different suspension culture lines were established from plants of two Aphelandra species (Acanthaceae). All established lines were analyzed for secondary metabolite accumulation. A discrepancy between secondary metabolites accumulated in the plants and in the cell cultures could be observed. All established Aphelandrasp. cell cultures produced verbascoside (acteoside) as the major extractable metabolite. Time course experiments were carried out to investigate the relationship between cell growth and verbascoside production. In the present study it was shown that verbascoside accumulation was growth dependent and positively related to the presence of 2,4-D in the medium. The conditions in which verbascoside represents ca. 18% of cell culture weight have been defined. Free polyamines were detected in the cell culture lines cultivated in MS liquid medium (cysteine 10 mg l^-1, thiamine 1 mg l^-1, 2,4-D 1 mg l^-1, kinetin 0.2 mg l^-1 and sucrose 30 g l^-1). Putrescine and spermidine accumulated within 8 days to a maximum of 8.4 μmol g^-1 of dry wt and 2.6 μmol g^-1 of dry wt respectively and thereafter their concentration decreased rapidly. There was no evidence for the presence of spermine or any other type of free or conjugated polyamines in the tested cell culture lines. This revised version was published online in June 2006 with corrections to the Cover Date.     

Human bronchial artery blood flow after lung Tx with direct bronchial artery revascularization.

The inaccuracy of measuring human bronchial artery blood flow has previously been considerable. En bloc double-lung transplantation with bronchial artery revascularization (BAR) using a single conduit offers the unique opportunity of direct measurement of the total bronchial artery blood flow. In eight en bloc double-lung-transplanted patients with complete BAR, the basal blood flow was measured by using a 0.014-in. Doppler guide wire and arteriography. The average peak velocity in the conduit was 12-73 cm/s [+/-2.1 (SD) cm/s], and the conduit diameter was 1.7-3.1 mm [+/-0.10 (SD) mm], giving individual basal flow values between 19 and 67 ml/min [+/-5 (SD) ml/min], or 0.2-1.9% of estimated cardiac output. In three patients basal measurements were followed by injection of nitroglycerin and verapamil into the conduit. This increased the bronchial artery flow to 121-262% of basal values (31-89 ml/min). The measured values appear more physiologically plausible than previous bronchial artery blood flow measurements in humans.     

Ein Sammelplatz der Kraniche

Ohne Zusammenfassung     

Application of machine learning methods to pathogen safety evaluation in biological manufacturing processes

The production of recombinant therapeutic proteins from animal or human cell lines entails the risk of endogenous viral contamination from cell substrates and adventitious agents from raw materials and environment. One of the approaches to control such potential viral contamination is to ensure the manufacturing process can adequately clear the potential viral contaminants. Viral clearance for production of human monoclonal antibodies is achieved by dedicated unit operations, such as low pH inactivation, viral filtration, and chromatographic separation. The process development of each viral clearance step for a new antibody production requires significant effort and resources invested in wet laboratory experiments for process characterization studies. Machine learning methods have the potential to help streamline the development and optimization of viral clearance unit operations for new therapeutic antibodies. The current work focuses on evaluating the usefulness of machine learning methods for process understanding and predictive modeling for viral clearance via a case study on low pH viral inactivation.     

Beobachtungen und Aufzeichnungen in der Umgegend von Leipzig w?hrend des Jahres 1907

Ohne Zusammenfassung     

Ein Beitrag zur Ornis der n?heren Umgegend von Leipzig

Ohne Zusammenfassung     

Reaction of bone marrow after cryo- and thermolesions on internal organs

Focal thermo- and cryolesions were placed on one kidney and the liver of Wistar rats. The wound healing was investigated histologically and by tritiated thymidine autoradiography. Furthermore, the 3H labeling indices of neutrophilic and eosinophilic promyelocytes and myelocytes as well as that of erythroblasts were determined in bone marrow samples from femur and vertebra. Normal nonoperated rats and rats which underwent sham operation (simple laparotomy) served as controls. The cryonecrosis healed completely after 4 weeks, whereas thermonecrotic areas were still observed 12 weeks after operation. The maximum mesenchymal and epithelial proliferation occurred between the 2nd and 3rd postoperative days. In the bone marrow, the highest labeling indices were estimated in animals with thermonecrosis, with values remaining increased during the 2 weeks after operation. Significant differences between the bone marrow response after cryolesions and sham operation were not observed. Thermolesions of internal organs, for example, after electrocoagulation, evoke a persisting local granulomatous inflammation accompanied by a distinct bone marrow reaction probably because of the pure resorption of carbonized tissue components. Iatrogenic cryolesions, in contrast, are characterized by a quick and uncomplicated wound healing without a significantly increased proliferation of bone marrow cells, thus corresponding to the wound healing after sham operation.     

Polarity, aperture condition and germination in pollen grains ofEphedra (Gnetales)

Pollen grain polarity, aperture condition and pollen tube formation were examined inEphedra americana, E. foliata, E. rupestris, E. distachya, andE. fragilis using LM, SEM and TEM. In the characteristic oblate pollen, as seen in situ in the tetrad configuration, the polar axis is the minor one and the equatorial plane runs between the two narrow ends of the microspore. The intine is thick in fresh fixed mature pollen but we have seen no indication of regions having an exceptionally thick intine that could be considered associated with an aperture or apertures. About three minutes after transferring fresh pollen to the germinating medium the ridged exine splits and twists away from the intine and its enclosed protoplast. The shed exine spreads out and curls into a scroll-like configuration that is as distinctive as that of the pollen shape had been but now having the ridges and valleys perpendicular to the long axis. The pollen tube develops, in our experience with more than a hundred germinating pollen grains, near one of the narrow tips of the pollen grain's equatorial plane. The location of the pollen tube initiation probably is related to the position of the tube cell nucleus. The pollen tube starts to grow about one hour after the exine was shed. The pollen tube emerges close to the narrow end (equator) of the gametophyte. This end emerged first as the exine is shed and is opposite to the prothallial cells. The stout pollen tube is c. 10µm in diameter grown in vitro on agar. In our germination medium the stout tube continued to elongate for about 24 hours reaching a length of c. 100 µm. With respect to exine morphology the aperture condition could be considered as inaperturate. The pollen tube, however, is formed in a germination area near one end of the exineless gametophyte.