Polymorphism of transferrin and esterase in Alaskan wolves: evidence of close molecular homology with the dog

By the use of isoelectric focusing in polyacrylamide gels serum samples from 146 Alaskan wolves were studied with regard to transferrin (Tf) and esterase (ArE) polymorphism, comparing the phenotypic band patterns with those of selected Norwegian dogs. The study revealed Tf and ArE polymorphisms in the wolf with phenotypic band patterns being indistinguishable from the corresponding ones in dogs. This suggests the occurrence of the same two common Tf alleles in the wolf as in the dog. In the ArE system the results are consistent with the occurrence of three alleles which also occur in dogs whereas a fourth allele, so far not seen in dogs, is seen in Alaskan wolves.     

Specific baroreceptor control of vertebral and cardiac sympathetic activity.

The effect of bilateral carotid occlusion (BCO) on the activity of the vertebral and cardiac sympathetic efferent nerves was studied in gallamine-immobilized and artificially ventilated cats under chloralose-urethane anaesthesia. Electrical activity of the vertebral and cardiac nerves (VNA and CNA), their integram, arterial blood pressure and respiration were recorded. BCO led to an increase in VNA persisting throughout the occlusion period, while merely a transient increase took place in CNA. When blood pressure was kept at a constant level or the depressor nerves was transected, CNA responded to BCO with a lasting increase. Electrical stimulation of the central stump of the left depressor nerve inhibited CNA much more than VNA. It is assumed that the selective inhibition of CNA, after a transient increase, arises as a consequence of a rise in blood pressure, i.e. of consecutive aortic baroreceptor excitation.     

Xylem Hydraulic Characteristics, Water Relations and Wood Anatomy of the Resurrection PlantMyrothamnus flabellifoliusWelw.

Myrothamnus flabellifoliusWelw. is a desiccation-tolerant (‘resurrection’)plant with a woody stem. Xylem vessels are narrow (14 µmmean diameter) and perforation plates are reticulate. This leadsto specific and leaf specific hydraulic conductivities thatare amongst the lowest recorded for angiosperms (k_s0.87 kg m^-1MPa^-1s^-1;k_l3.28x10^-5kg m^-1MPa^-1s^-1, stem diameter 3 mm). Hydraulic conductivitiesdecrease with increasing pressure gradient. Transpiration ratesin well watered plants were moderate to low, generating xylemwater potentials of -1 to -2 MPa. Acoustic emissions indicatedextensive cavitation events that were initiated at xylem waterpotentials of -2 to -3 MPa. The desiccation-tolerant natureof the tissue permits this species to survive this interruptionof the water supply. On rewatering the roots pressures thatwere developed were low (2.4 kPa). However capillary forceswere demonstrated to be adequate to account for the refillingof xylem vessels and re-establishment of hydraulic continuityeven when water was under a tension of -8 kPa. During dehydrationand rehydration cycles stems showed considerable shrinking andswelling. Unusual knob-like structures of unknown chemical compositionwere observed on the outer surface of xylem vessels. These maybe related to the ability of the stem to withstand the mechanicalstresses associated with this shrinkage and swelling.Copyright1998 Annals of Botany Company cavitation, desiccation, hydraulic conductivity, refilling, resurrection plant, root pressure, xylem anatomy,Myrothamnus flabellifolius     

Use of hepatocytes cultured in microcarriers for correction of acute hepatic insufficiency

The ability of hepatocytes cultured on Biosilon microcarriers to secrete albumin and to conjugate bilirubin were examined for the purpose of developing an artificial liver support system. Cultured hepatocytes were able to synthesize 100-120 micrograms albumin per 10(5) cells in 24 hours and to conjugate about 20 micrograms/hr of bilirubin for at least 5 days. Rats with liver failure caused by i.p. injection of CCL4 or D-galactosamine were subjected to hemosorption via minicolumns containing 2 ml of Biosilon microcarriers with 40 X 10(6) cultured hepatocytes. The procedure was performed 20-24 h after hepatotoxins injection and lasted for 3 h at a flow rate of 60 ml/h. This reduced mortality from 100% to 20% after 48% and to 40% after 7 days in case of CCl4 and from 100% to 40% after 48 h and 7 days in case of D-galactosamine. Our results suggest that hepatocytes cultured on microcarriers may be efficiently applied to correction of fulminant hepatic failure caused by different hepatotoxins.     

Magnetic resonance tomography of the sellar region in patients with endocrine diseases]

The authors discuss the present-day problems of radiotherapy. They show the major prospective trends in this field and describe the OS3Dplan system, made in this country, that represents a working place of a radiologist and serves for the development, analysis and storage of the schemes of long-distance gamma-beam therapy of oncologic patients. The OS3Dplan system is realized via the IBM PC/AT-286/287 computer but can operate with any of the IBM PC/XT/AT/PS-2--8086/80486 computers, made before 1986 with the videoadapter EGA/VGA, and functioning under MS-DOS, Microsoft (version 3.3 or older). The mathematical provision of the videodigitizer (distance control and videocamera) permit the introduction of videoinformation into the personal computer in the 256 x 256 format, 512 x 512 pixels. The mathematical provision of the OS3Dplan proper permits a volume planning of long-distance gamma-beam therapy. This module type system will be of interest for various specialists (radiologists, roentgenologists, oncologists, students, etc.), for it permits a collection and maintenance of a data bank on patients with imaging of roentgenograms, CT, NM tomography, ultrasonic data on the computer display and printing these data, perform metric analyses and reconstruct the volume.