A case of a 61-year-old diabetic patient who had a new onset simple partial seizure is presented. Past medical history was remarkable for pulmonary sarcoidosis for which the patient was on chronic steroid therapy. Computed tomography scan demonstrated a postcentral abscess which was aspirated under stereotactic guidance. Nocardia asteroides was identified. The patient was placed on intravenous trimethoprim and sulfamethoxazole. He required two further stereotactic aspirations of recrudescences until symptoms resolved. The use of repeated stereotactic aspiration in place of an open surgical procedure is advocated for the treatment of nocardial abscesses.

BACKGROUND AND PURPOSE:This work was undertaken to improve the definition of target volumes for radiosurgery using the angiographic and CT data.MATERIALS AND METHODS:The basis of this new method is to combine both imaging modalities and to compare them in each representation, i.e. to plot the volume obtained by angiography on CT images and also the contours defined by the CT on angiographic films. To obtain the angiographic volume, the radiographs are taken at several incidence angles. The X-ray sources position and the position of the films are determined using rectangular markers, then the intersection of all the loci of the target volume are calculated.RESULTS:Verifications with a phantom show the accuracy of the procedure and the benefit obtained by increasing the number of angles of incidence in the angiographic imaging. The centre of gravity of the experimental target could be localized to an accuracy of better than 0.4 mm. The method was used in 11 clinical cases with excellent clinical results.CONCLUSIONS:The method can be easily applied and improves the delineation of target volumes in radiosurgery. CT data counterbalances the relative weakness of angiography concerning the three-dimensional geometry. Angiography adds useful information on the blood flow that is not shown in CT. Almost all the presented clinical cases benefit from the technique described here.

We report the first series of patients treated by stereotactic radiation therapy for brain metastases in Switzerland. From August 1993 to December 1934, 19 patients were treated using a linear accelerator adapted for stereotactic treatment set-up. Most of the patients received combined treatment including external irradiation. The crude overall control rate for brain metastases was 79%. Median survival was 12.2 months. Overall survival at one year was 50+/-12%. These data compare reasonably well with the reported median survival of 3-6 months using external cranial irradiation alone. There was no <> The data thus indicate that stereotactic radiation therapy combined with external whole brain irradiation appears to increase life expectancy and quality of life in a selected cohort of patients.

Disseminated intravascular coagulation (DIC) is an extremely rare complication during elective brain tumor surgery. We report the case of a life-threatening intraoperative hemorrhagic diathesis due to a fulminating DIC during the removal of a grade III parietooccipital astrocytoma in a patient with a history of three pulmonary embolisms. Intraoperatively, the patient required 13 U of blood, 9 U of fresh-frozen plasma, and 5.45 L of colloids and crystalloids (total volume infused during the procedure: 12.5 L). Bleeding persisted for 24 h and required further blood component therapy. Laboratory data support the diagnosis of DIC: decreased fibrinogen and platelet count, prolonged thrombin and prothrombin times, and the presence of fibrin monomers. With aggressive and swift treatment of the DIC, the patient survived with transient neurological worsening.

A variant clone of Hyoscyamus muticus (VIIIB9) with a specific, stable requirement for tryptophan has been shown to have the following characteristics: (i) no accumulation of tryptophan from anthranilic acid; (ii) growth on added tryptophan or indole but not on anthranilic acid; (iii) accumulation of indole-3-glycerol phosphate and other indole derivatives; (iv) extractable activity of the enzymes for tryptophan biosynthesis, including the partial reaction 2 of tryptophan synthase but not reactions 1 or 3. Thus these data provide in-vivo evidence for the existence of a two-component, bacterial-type tryptophan synthase in plants, the tryptophan auxotrophy of VIIIB9 probably being the consequence of a mutation in the α-subunit of the tryptophan-synthase complex.

The design of a robot for functional stereotactic surgery which is under construction in our laboratory is described. The main features include operation inside the computed tomographic (CT) scanner, the possibility of intraoperative CT scanning and complete handling of the stereotactic probes by the robot.

The robot technology was introduced into a new stereotactic neurosurgery system for applications to biopsy, blind surgery, and functional neurosurgery. The authors have developed a newly designed prototype microsurgical robot, designed to allow a biopsy needle to reach the target such as a cerebral tumor within a brain automatically on the basis of the X, Y, and Z coordinates obtained by CT scanner. This robot is so small that it can be driven in a CT scanner gantry. It consists mainly of the link mechanism and the insertion mechanism. We constructed the link mechanism and investigated its working space.

O-Methylthreonine (OMT) inhibits the growth of plated Rosa cells (ID50≃6·10(-6)M). Isoleucine is able to reverse efficiently and specifically this OMT toxicity. From OMT-resistant colonies occurring at a frequency of 1.58·10(-7) variants per cell plated at 10(-4)M OMT, the variant strains OMT(R)-1 and OMT(R)-2 were isolated, cloned via protoplasts and characterized. Both variants were ten times more resistant to OMT than the wildtype and were cross-resistant to another isoleucine analog, DL-4-thiaisoleucine. The resistant variants retained their resistance after storage for three years in liquid nitrogen. Both resistant strains were stable for several months when subcultured in the absence of OMT although it was shown in a reconstitution experiment that wildtype cells overgrow OMT(R)-2 variant cells if co-cultivated for many passages in drug-free medium. One case of instability was observed upon long-term subculturing in drug-free medium: the strain OMT(R)-1D(*) partially lost phenotypic properties. Resistance to OMT was followed qualitatively by a new method based on inhibition-zone formation in cell suspensions plated in agar medium. The OMT-resistant variants showed a reduction in sensitivity of the enzyme L-threonine deaminase to feedback inhibition by isoleucine, a decreased stability of L-threonine deaminase when stored at-18°C or incubated at +55°C and a two- to threefold increase of the free isoleucine pool within the cells. The genetical events and the biochemical mechanisms which might lead to the observed stable and biochemically defined character are discussed with particular reference to the high ploidy level of the Rosa cell line.

Four nitrate non-utilizing clones of Hyoscyamus muticus, obtained by a total isolation method, possess all the known characteristics of cnx-type nitrate-reductase-deficient variants: 1) strict dependence on a reduced nitrogen source such as a mixture of amino acids; 2) chlorate resistance; 3) normal nitrate uptake; 4) lack of nitrate-reductase and xanthine-dehydrogenase activities, but presence of cytochrome-c-reductase and nitrite-reductase activities; 5) in vitro nitrate-reductase complementation with a molybdenum cofactor source. Two of the clones (MA-2 and I2D12) are molybdate repairable in vivo, whilst the other two clones (VIC2 and XIVE9) are not.

Solutions used for protoplast preparations, manipulations and culture were adjusted to the osmotic pressure of 400 mOs kg 1H2O and filter sterilized. Protoplasts were isolated 1–2 days after subculture in enzyme solution containing cellulase Onozuka R-10 2.0

Complementation of a nitrate reductase deficient variant of Hyoscyamus muticus (MA-2) and nitrate reductase apoenzyme (nia-115) and cofactor mutants (cnx-68) of Nicotiana tabacum was studied by protoplast fusion. Selection of prototrophic intergeneric somatic hybrids was achieved in combination of MA-2 with the apoenzyme mutant nia-115 of N. tabacum. The H. muticus MA-2 line was therefore classified to be a cnx type variant possessing an altered molybdenum cofactor of the nitrate reductase enzyme complex but unaffected in the apoprotein of nitrate reductase. The nitrate reductase deficient and chlorate resistant characters of MA-2 were functionally coupled recessive traits. Nitrate reductase activity accompanied by chlorate sensitivity could be detected only under inductive conditions in the somatic hybrids. The inductive expression of nitrate reductase in the somatic hybrids arising from the combination of cells harbouring either the inductive or constitutive type nitrate reductase is discussed.

The roles of sulfur and nitrogen in cell nutrition show many similarities. Both must be reduced by living systems to form proteins and other macromolecules and both, therefore, appear among the macroelements required by plants and plant-like microorganisms. Nutritional interactions between the two elements have been described (Friedrich and Schrader, 1978) and both elements show a rather uniform distribution throughout the tissues and Organs of higher plants and among cells of microorganisms. Sulfate reduction occurs in mitochondria and microbodies in Euglena cells (Brunold and Schiff, 1976) and is localized in the plastids of higher plants (Schmidt and Schwerin, 1971; Schwenn and Trebst, 1976). Since cell, tissue, and organ cultures can be grown on sulfateasasolesulfursource (White, 1963; White and Grove, 1965;Butenko, 1968; Thomas and Davey, 1975), and since nongreen tissues such as beet discs (Ellis, 1963) and roots (Pate, 1965) reduce sulfate, assimilatory sulfate reduction must be widely distributed throughout the plant; studies of the localization of certain enzymes of sulfate reduction are in agreement (Mayer, 1967; Ellis, 1969; Onajobi et al., 1973; Schmidt, 1976; Tamura et al., 1976; Cacco et al., 1977; Fankhauser and Brunold, 1978, 1979). In this paper we will try to summarize what is known of the process of assimilatory sulfate reduction and how it might have evolved; some recent work on an enzymatic reaction of adenosine 5′ phosphosulfate (APS) and ammonia (Fankhauser et al., 1979; Fankhauser and Schiff, 1980; Fankhauser et al., 1980) will also be described which may provide a connection between sulfur and nitrogen metabolism.

We have extracted and purified a nucleotide from cells of Chlorella, pyrenoidose Chick which shares the following properties with adenosine 5′ phosphoramidate; electrophoretic mobility in sodium bicarbonate and in sodium borate buffer (pH 8.0); retention time on high performance liquid chromatography; ultraviolet absorption spectrum at pH 1–2 and 7–9; a yield of one mole each of adenine, ribose, total phosphate and ammonia released at low pH; and formation of adenosine 5′ monophosphate on acidification or treatment with 3′:5′-cyclic-nucleotide phosphodiesterase (EC3.1.4.17). Although formation of APA from its precursor adenosine 5′ phosphosulfate during extraction and purification is not expected this appears to be excluded by the use of low temperature throughout purification and the finding that [14C] APS added before extraction does not significantly label the adenosine 5′ phosphoramidate isolated. Thus adenosine 5′ phosphoramidate appears to be a normal constituent of Chlorella cells like the enzyme which forms it: adenylyl sulfate: ammonia adenylyl transferase.

Roots and hypocotyls of 11 day-old spinach seedlings with fully developed cotyledons contained 30–35% of the total O-acetyl-L-serine sulfhydrylase (OASSase) extractable from the plants.

Roots of spinach (Spinacia oleracea L.) seedlings contained only a very low activity of adenosine 5′-phosphosulfate sulfotransferase compared to the cotyledons. Adenosine 5′-phosphosulfate sulfotransferase activity increased about tenfold in cotyledons during greening. Preparation of organelle fractions from spinach leaves by a combination of differential and isopycnic density gradient centrifugation showed that adenosine 5′-phosphosulfate sulfotransferase banded with NADP-glyceraldehyde-3-phosphate dehydrogenase, a marker enzyme for intact chloroplasts. In the fractions of peroxisomes, mitochondria and broken chloroplasts virtually no adenosine 5′-phosphosulfate sulfotransferase activity was measured. Comparison with the chloroplast enzyme NADP-glyceraldehyde-3-phosphate dehydrogenase indicates that in spinach, adenosine 5′-phosphosulfate sulfotransferase is localized almost exclusively in the chloroplasts.