Fungal products. Part XVII. Microbiological hydroxylation of gibberellin A9 and its methyl ester

Angiotensin II (A II) and analogues were tested for their ability to restore electrical and mechanical activity to cardiac muscle preparations in which the fast Na+ channels had been inactivated by partial depolarization (22-27 mM K+) or by tetrodotoxin (TTX). The partially depolarized or TTX-blocked preparations were chosen because under these conditions electrical and mechanical responses are primarily Ca2+ -dependent. In depolarized rabbit right atria, A II restored spontaneous mechanical and electrical activity (measured by both intracellular and extracellular recording techniques). The frequency of action potential discharge was concentration-dependent; the threshold concentration of A II was 10(-10) M, the ED50 was 8 X 10(-9) M, and the maximum effect was observed at 5 X 10(-8) M. In contrast, depolarized guinea pig atria were insensitive to A II, Sar1-angiotensin II, and des-Asp1-angiotensin II, even at concentrations as high as 10(-5) M. Rabbit papillary muscle (TTX-blocked), embryonic (18-day) chick heart (partially depolarized) and chick heart reaggregates (TTX-blocked) responded similarly to rabbit atria in that A II (9.6 X 10(-7) M) restored both electrical and mechanical activity. We found that in these preparations the action of A II was unaffected by propranolol (5.0 X 10(-6) M to 5.0 X 10(-5) M) but was blocked by Mn2+ (10(-3) M), D-600 (1 X 10(-7) g/ml) and the specific A II antagonists Sar1-Ala8-angiotensin II (P-113) (5.0 X 10(-5) M) and Sar1-Ile8-angiotensin II (5.28 X 10(-5) M). We conclude that the positive inotropic effect of A II on the myocardium is due to its ability to increase transmembrane ion movements in or through the cell membrane. The ability of Mn2+ and D-600 to block this effect suggests that this ion movement is via the so-called "slow channels."     

Location of nucleolar organizing regions on the chromosomes of the Syrian hamster (Mesocricetus auratus) and the Djungarian hamster (Phodopus sungorus)

Terminal chromosome associations ("satellite associations") in ASG-banded preparations have been used to determine the number and location of staellites in the Syrian hamster (Mesocricetus auratus) and the Djungarian hamster (Phodopus sungorus). Five pairs of satellites are found in the former and four in the latter. Nucleolar organizing regions (NORs) were visualized with the Ag-AS silver precipitation technique, and their number and position corresponded exactly with the number and position of satellites in Phodopus, where positive chromosome identification can be made in the absence of banding. Numerical agreement is exact in Mesocricetus as well, and the morphology of the silver-tagged NOR-bearing chromosomes strongly suggests that corrrespondence also occurs in this species.     

Production of anti-erythrocyte antibodies by leukemic and nonleukemic B cells in chronic lymphocytic leukemia patients

We have assessed the specificity of antibodies from the leukemic B cells of five patients with both chronic lymphocytic leukemia and autoimmune hemolytic anemia (CLL-AHA). Leukemic cells from one patient displayed surface immunoglobulin with heavy and light chain isotypes identical to that of the patient's anti-red blood cell (RBC) antibodies, and the leukemic cells secreted antibodies in vitro with anti-RBC activity. However, in the remaining patients, the leukemic cells displayed surface immunoglobulin with light chain isotypes different from that of the patient's anti-RBC antibodies and secreted antibodies in vitro with no detectable anti-RBC activity. Thus, there are two distinct classes of CLL-AHA patients, differentiated by the presence or absence of an anti-RBC antibody-producing leukemic B cell clone. The apparent heterogeneity in the source of pathogenic anti-RBC antibodies may impact the treatment response of the two classes of CLL-AHA patients.     

Protein Quality of Selected Muscle Foods as Affected by the Exchange of Dietary Wheat Bran for Cellulose

The exchange of 8.4% neutral detergent fiber (NDF) of wheat bran for 8.3% NDF of cellulose in diets containing either beef, chicken, fish or casein as protein sources did not (P>0.05) alter feed consumption, weight gain or energy intake in the protein efficiency ratio (PER) bioassay with weanling rats. Higher (P<0.05) fecal nitrogen (N) excretions and lower (P<0.05) N digestibilities occurred for each protein source when wheat bran was exchanged for cellulose. The exchange also had no effect (P>0.05) on PER or net protein ratio (NPR) of casein or fish protein or on NPR of chicken protein. However, PER and NPR of beef and PER for chicken were reduced (P<0.05) when the dietary fiber was exchanged.     

Physical-Chemical Characteristics of Partially Clarified Guava Juice and Concentrate

Partially clarified guava juice concentrate was prepared from single strength guava puree (5.5°Brix) by treatment with pectinase (2 hr at 50°C), extraction of juice with a rack-and-cloth press, and vacuum concentration to 23°Brix. The concentrate had the following characteristics: density, 1.10; pH, 3.16; total acids, 4.67%; ash, 1.51%; moisture, 72.4%; ascorbic acid, 867 mg%; viscosity, 4.4 cp; and CIE L* 39.2, CIE a* 10.33, CIE b* 27.11.     

Computation of Running Averages

This brief presents and compares several recursive and nonrecursive techniques for the efficient computation of the running average of discrete signals. First of all, the standard recursive algorithm is considered and its long-term accuracy is assessed when the floating-point arithmetic is employed. A cheap refreshing strategy is proposed as a means of keeping the computed value close enough to the exact one. Then, two alternative nonrecursive algorithms, requiring only log₂N additions, are developed, which are as reliable and accurate as the direct implementation     

A broadband multimedia collaborative system for advancedteleradiology and medical imaging diagnosis

This paper presents a new telemedicine system currently in routine clinical usage, developed within the European Union (EU) ACTS BONAPARTE project. The telemedicine system is developed on an asynchronous transfer mode (ATM) multimedia hardware/software platform comprising the following set of telemedicine services: synchronous cooperative work, high-quality video conference, multimedia mail, medical image digitizing, processing, storing and printing, and local and remote transparent database access. The medical information handled by the platform conforms to the Digital Imaging and Communications in Medicine (DICOM) 3.0 medical imaging standard. The telemedicine system has been installed for clinical routines in three Spanish hospitals since November 1997 and has been used in an average of one/two clinical sessions per week. At each clinical session, a usability and clinical evaluation of the system was carried out. Evaluation is carried out through direct observation of interactions and questionnaire-based subjective data. The usability evaluation methodology and the results of the system usability study are also presented in this article. The experience gained from the design, development, and evaluation of the telemedicine system is providing an indepth knowledge of the benefits and difficulties involved in the installation and clinical usage of this type of high-usability and advanced multimedia telemedicine system in the field of teleradiology and collaborative medical imaging diagnosis     

Passive alignment optical subassemblies for military/aerospacefiber-optic transmitter/receiver modules

Under the DARPA sponsored Avionics Optoelectronic Module Technology program, new passive alignment carrier (PAC) optical subassemblies (LED-PAC and PIN-PAC) ruggedized for military/aerospace avionics fiber-optic transmitter and receiver applications have been developed, LED-PAC and PIN-PAC silicon micro-optical bench substrates were fabricated together on a 5 in diameter silicon wafer via multistage photolithography, thin-film, and substrate processing. Alignment v-grooves designed for passive optical alignment of 100/140 μm multimode optical fiber to the optoelectronic devices were terminated by solder locking the fiber to the silicon PAC substrates. The LED-PAC comprising a surface emitting LED die-bonded onto a novel precision molded AM submount passively mounted onto the silicon microbench achieves the required high coupling efficiency to 100/140 μm multimode optical fiber to meet stringent avionics transmitter output power requirements. The 100/130 μm multimode optical fiber-pigtailed PIN-PAC with a refractive lens etched into the p-i-n photodiode backside surface exhibited responsivities greater than 0.8 A/W at 1.3 μm wavelength. The LED-PAC and PIN-PAC optical subassemblies integrated with Boeing ARINC 636 (FDDI) transmitter and receiver thick film multichip (MCM-C) circuitry are capable of meeting both ARINC 636 and FDDI physical layer requirements     

Bovine longissimus muscle tenderness as affected by postmortem aging time, animal age and sex

Strip loins were removed from 10 bulls and 10 steers ～14 mo old and from 10 cows ≥ 44 mo. Samples were removed at 3, 7, 14, and 28 days postmortem. Shear-force values were measured. Sensory evaluation was done by a 15-member trained panel. Animal age and postmortem aging time had more influence on tenderness attributes than did sex of the animal. Increased postmortem aging time improved tenderness attributes regardless of sex or age.