Octopamine receptor subtypes and their modes of action

Octopamine receptor subclasses were first proposed to explain differences in the pharmacological profiles of a range of physiological responses to octopamine obtained in the extensor-tibiae neuromuscular preparation of the locust. Thus, OCTOPAMINE₁ receptors which inhibit an endogenous myogenic rhythm, increase intracellular calcium levels. Also OCTOPAMINE₂ receptors which modulate neuromuscular transmission in this preparation, increase the level of adenylate cyclase activity. The current status of this classification is reviewed by examining the pharmacology of responses to octopamine in a range of preparations. It is concluded that the distinction between OCTOPAMINE₁ and OCTOPAMINE₂ receptor types is still valid, but that OCTOPAMINE₂ receptors exhibit some tissue specific variations. Studies on a clonedDrosophila octopamine/tyramine (phenolamine) receptor are discussed and illustrate many of the difficulties presently encountered in making a definitive classification of octopamine receptors. These include the possibilities that single receptors may activate multiple second messenger systems and that different agonists may differentially couple the same receptor to different second messenger systems.     

Binding-protein expression is subject to temporal,developmental and stress-induced regulation in terminally differentiated soybean organs

Binding protein (BiP) is a widely distributed and highly conserved endoplasmic-reticulum luminal protein that has been implicated in cotranslational folding of nascent polypeptides, and in the recognition and disposal of misfolded polypeptides. Analysis of cDNA sequences and genomic blots indicates that soybeans (Glycine max L. Merr.) possess a small gene family encoding BiP. The deduced sequence of BiP is very similar to that of other plant BiPs. We have examined the expression of BiP in several different terminally differentiated soybean organs including leaves, pods and seed cotyledons. Expression of BiP mRNA increases during leaf expansion while levels of BiP protein decrease. Leaf BiP mRNA is subject to temporal control, exhibiting a large difference in expression in a few hours between dusk and night. The expression of BiP mRNA varies in direct correlation with accumulation of seed storage proteins. The hybridization suggests that maturing-seed BiP is likely to be a different isoform from vegetative BiPs. Levels of BiP protein in maturing seeds vary with BiP mRNA. High levels of BiP mRNA are detected after 3 d of seedling growth. Little change in either BiP mRNA or protein levels was detected in maturing soybean pods, although BiP-protein levels decrease in fully mature pods. Persistent wounding of leaves by whiteflies induces massive overexpression of BiP mRNA while only slightly increasing BiP-protein levels. In contrast single-event puncture wounding only slightly induces additional BiP expression above the temporal variations. These observations indicate that BiP is not constitutively expressed in terminally differentiated plant organs. Expression of BiP is highest during the developmental stages of leaves, pods and seeds when their constituent cells are producing seed or vegetative storage proteins, and appears to be subject to complex regulation, including developmental, temporal and wounding.The mention of vendor or product does not imply that they are endorsed or recommended by the U.S. Department of Agriculture over vendors of similar products not mentioned.Abbreviations BiP binding protein The sequences reported in this paper have been submitted to Gen-Bank and are identified with the accession numbers BiP-A (U08384), BiP-B (U08383), BiP-C (U08382) and -1,3 glucanase (U08405).     

University acknowledges special risks,introduces drug program for anesthetists.

Anesthetists are at special risk for becoming addicted to some of the drugs they work with. The problem was highlighted by the recent death of a physician in Comox, BC, and a doctor''s brush with death at a hospital near Ottawa. The University of Ottawa has responded with a program, the professional Assistance Program for the Impaired or Disabled Physician, that is in the final stages of approval. Although it will be aimed initially at anesthetists and anesthesia residents in the university''s teaching hospitals, there are hopes the program will spread eventually to other medical departments.     

Home care for patients with suspected myocardial infarction: use made by general practitioners of a hospital team for initial management.

Two hundred and sixty three general practitioners were offered the use of a hospital based service consisting of a medical senior house officer, a nurse attached to a coronary care unit, and a specially equipped ambulance estate car to help with the initial management of patients with suspected myocardial infarction who might be suitable for home care. One hundred and sixty nine general practitioners registered as potential users of this service; during 22 months they called the hospital team to see 271 patients, 235 of whom the team suspected had indeed suffered a myocardial infarction. During the same period, however, these general practitioners also admitted 317 patients with suspected myocardial infarction directly to hospital. Other general practitioners admitted 323 patients and deputising doctors 258. A further 529 patients with suspected infarction were admitted without the intervention of a general practitioner. Of the patients seen by the team, 54 required immediate admission to hospital; 17 of the remaining patients who initially appeared suitable for home care later required admission to hospital. In a large city such as Nottingham the provision of hospital based facilities to help general practitioners with home management is unlikely to make an appreciable impact on the overall pattern of care of patients with suspected myocardial infarction.     

Screening and genetic counseling for beta-thalassemia trait in a population unselected for interest: effects on knowledge and mood.

To evaluate the effects of genetic screening and counseling in a population unselected for interest, adults in a health maintenance organization (HMO) were screened for beta-thalassemia trait as part of health care or multiphasic screening. Counseling was provided by either a trained physician or a videotape containing the same information, followed by an opportunity to question a trained physician. Knowledge of thalassemia, knowledge of genetics, and mood were assessed by standardized questionnaires and by interview immediately before and after counseling. Compared to controls, trait subjects demonstrated significant learning about thalassemia (P less than .001) and about genetics (P less than .001) and recorded significant mood changes, namely, surprise (startle) (P less than .05), increased alertness (decreased deactivation) (P less than .05), and decreased skepticism (P less than .01). Screening and genetic counseling for beta-thalassemia trait conducted as part of multiphasic screening of the population of a HMO, essentially and unselected population, can result in significant overall learning with acceptable effects on mood.     

Radiation Resistance and Injury of Yersinia enterocolitica

The D values of Yersinia enterocolitica strains IP134, IP107, and WA, irradiated at 25°C in Trypticase soy broth, ranged from 9.7 to 11.8 krad. When irradiated in ground beef at 25 and −30°C, the D value of strain IP107 was 19.5 and 38.8 krad, respectively. Cells suspended in Trypticase soy broth were more sensitive to storage at −20°C than those mixed in ground beef. The percentages of inactivation and of injury (inability to form colonies in the presence of 3.0% NaCl) of cells stored in ground beef for 10 days at −20°C were 70 and 23%, respectively. Prior irradiation did not alter the cell's sensitivity to storage at −20°C, nor did storage at −20°C alter the cell's resistance to irradiation at 25°C. Added NaCl concentrations of up to 4.0% in Trypticase soy agar (TSA) (which contains 0.5% NaCl) had little effect on colony formation at 36°C of unirradiated Y. enterocolitica. With added 4.0% NaCl, 79% of the cells formed colonies at 36°C; with 5.0% NaCl added, no colonies were formed. Although 2.5% NaCl added to ground beef did not sensitize Y. enterocolitica cells to irradiation, when added to TSA it reduced the number of apparent radiation survivors. Cells uninjured by irradiation formed colonies on TSA when incubated at either 36 or 5°C. More survivors of an exposure to 60 krad were capable of recovery and forming colonies on TSA when incubated at 36°C for 1 day than at 5°C for 14 days. This difference in count was considered a manifestation of injury to certain survivors of irradiation.     

A Burkitt-lymphoma variant translocation (2p-; 8q+) in a patient with ALL,L3 (Burkitt type)

Summary A patient with acute lymphoblastic leukemia (ALL) whose cells had L3 (Burkitt-type) morphology was found to have a variant translocation t(2;8)(p13;q24), that has been reported only in Burkitt lymphomas. This observation provides additional evidence for a close association of particular karyotypic abnormalities with both Burkitt-type ALL and Burkitt lymphoma.     

Cryogenic gamma irradiation of prototype pork and chicken and antagonistic effect between Clostridium botulinum types A and B.

Inoculated, irradiated pork (2,300 cans) and chicken (2,000 cans) pack studies were performed to establish the 12D dose for these foods. Each can was inoculated with a mixture of 10(6) spores of each of 10 strains of Clostridium botulinum (five type A and five type B), or a total of 10(7) spores. The cans received a series of increasing doses of gamma rays (60Co) at -30 +/- 10 degrees C; they were incubated for 6 months at 30 +/- 2 degrees C and examined for swelling, toxicity, and recoverable botulinal cells. The highest rate of swelling for both foods occurred within the first week of incubation, and maximum swelling was observed within 4 to 5 weeks. The minimal experimental sterilizing dose (ESD) based on flat, nontoxic sterile cans was 3.0 less than ESD less than or equal to 3.2 Mrad for pork and 4.0 less than ESD less than or equal to 4.2 Mrad for chicken. An analysis of the partial spoilage data by extreme-value statistics indicated with 90% confidence that the rate of spore death in the two foods was not a normal distribution, but appeared to favor a shifted exponential function. Based on the latter distribution, and assuming one most resistant strain in the mixture of 10 used, the 12D dose computed to 4.37 Mrad, with a shoulder of 0.11 Mrad, for pork and to 4.27 Mrad, with a shoulder of 0.51 Mrad, for chicken. An assumption that there were two or more most resistant strains in the inoculum progressively lowered the 12D dose. There was an apparent antagonism between the irradiated type A and B viable strains in the two foods. Cans with type B cells and toxin predominated over cans with type A cells and toxin, but cans with a mixture of type A and B toxins predominated over cans with a mixture of Type A and B cells. At the highest sublethal doses, only type A cells survived in pork, but in chicken there was a least one type B strain that was at least as resistant as type A strains.     

Photochemical oxidation of tyrosinase

Dye sensitized photo-oxidation inactivates tyrosinases isolated from Neurospora and Agaricus. The rate of inactivation is enhanced by cyanide and is dependent on pH.     

An Improved Technique for Sequential R-, Q- and C-Banding of Bone Marrow Chromosomes

A procedure for the sequential staining of metaphase cells to provide R-banding, Q-banding and C-banding of chromosomes is described. The combined techniques allow more precise identification of marker chromosomes and more accurate definition of breakpoints in the consistent chromosome translocations that are associated with certain human malignancies.