Association between transfusion of whole blood and recurrence of cancer.

Transfusion affects the immune response to renal transplantation and may be associated with recurrence of various human neoplasms. Data from patients with colonic, rectal, cervical, and prostate tumours showed an association between transfusion of any amount of whole blood or larger amounts of red blood cells at the time of surgery and later recurrence of cancer. Recipients of one unit of whole blood had a significantly higher incidence of recurrence (45%) than recipients of a single unit of red cells (12%) (p = 0.03). Recipients of two units of whole blood also had a higher rate of recurrence (52%) than those receiving two units of red cells (23%) (p = 0.03). Recipients of any amount of whole blood had similar recurrence rates (38-52%). Recipients of four or more units of red blood cells had a higher rate of recurrence (55%) than those receiving three or fewer units of red blood cells (20%) (p = 0.005). Mortality due to cancer in patients receiving three or fewer units of red blood cells (2%) was similar to that in patients who did not have transfusions (7%) and significantly lower than that observed in patients receiving three or fewer units of whole blood (20%) (p = 0.003). A proportional hazards risk analysis showed that transfusion of any whole blood or more than three units of red blood cells was significantly associated with earlier recurrence and death due to cancer. These data support an association between transfusion and recurrence of cancer. They also suggest that some factor present in greater amounts in whole blood, such as plasma, may contribute to the increased risk of recurrence in patients who have undergone transfusion. Until the questions raised by retrospective studies of cancer recurrence and transfusion can be answered by prospective interventional trials with washed red blood cells, red blood cells should be transfused to patients with cancer in preference to whole blood when clinically feasible.     

Precocious induction of luteal activation and termination of delayed implantation in mink with the dopamine antagonist pimozide

The effects of the dopamine antagonist pimozide on the preimplantation delay phase of mink gestation were investigated in field and laboratory trials. Three doses of 0.1 mg pimozide in acetic acid administered on the 7th, 9th and 11th days after mating abbreviated gestation in Pastel kit female mink to a mean (+/- SEM) of 45.5 +/- 0.5 days, 10 days less than that observed in mink treated with vehicle only (55.6 +/- 0.6 days). In laboratory trials, four doses of 0.1 mg pimozide on the 7th, 9th, 11th and 13th day after mating resulted in embryo implantation at a mean of 25 +/- 4.3 days after mating while vehicle-treated control animals had mean preimplantation delay of 37 +/- 3.1 days. Luteal activation in the pimozide-treated group, as indicated by a rapid increase in circulating progesterone, began within 2 days after the first pimozide injection. No increase was observed in vehicle-treated mink until 6 or more days after the initiation of injections or 13 days after mating. It was concluded that pimozide, presumably by permitting endogenous secretion of prolactin, can induce precocious luteal activation and embryo implantation in the mink.     

Effects of secretin and gastric inhibitory polypeptide on human pancreatic growth hormone-releasing factor(1-40)-stimulated growth hormone levels in the rat

Synthetic human pancreatic growth hormone-releasing factor containing 40 amino acids ([hpGRF (1-40)]-OH) significantly stimulated plasma growth hormone (GH) levels in both sodium pentobarbital and urethane anesthetized rats. Synthetic secretin, gastric inhibitory polypeptide (GIP), and glucagon significantly decreased plasma GH levels while synthetic vasoactive intestinal peptide (VIP) had no effect. Secretin and GIP also altered the in vivo plasma GH response to [hpGRF(1-40)]-OH. Whether this effect is the result of an interaction at the pituitary level or is due to an extra-pituitary effect of secretin and GIP awaits further study.     

Brain and erythrocyte microtubules from chicken contain different beta-tubulin polypeptides

beta-Tubulin subunits isolated from chicken brain tissue and erythrocytes are distinguishable as unique biochemical species by electrophoretic and peptide mapping procedures. 1) The subunits of beta-tubulin exhibit major differences in electrophoretic mobility on sodium dodecyl sulfate-polyacrylamide gels that vary according to the pH and ionic strength of the gel. 2) The isoelectric points of urea-denatured beta subunits from brain tissue and erythrocytes are pH 5.1 and 5.4, respectively, whereas those of both alpha subunits are approximately pH 5.2.3) Two-dimensional peptide maps prepared with alpha-chymotrypsin or V8 protease show that alpha-tubulin peptides are indistinguishable, whereas beta-tubulin peptides are very different. Only one-third of the 15 major tyrosine-containing beta-tubulin peptides prepared with alpha-chymotrypsin are common to both beta-tubulin species. The data indicate that the beta-tubulin subunits of brain tissue and erythrocytes are biochemically distinct and may be different gene products. The presence of tubulin variants in brain tissue and erythrocytes may indicate special requirements for microtubule assembly and function in different cell types.     

Identity and origin of the ATPase activity associated with neuronal microtubules. II. Identification of a 50,000-dalton polypeptide with ATPase activity similar to F-1 ATPase from mitochondria

We determined that the ATPase activity contained in preparations of neuronal microtubules is associated with a 50,000-dalton polypeptide by four different methods: (a) photoaffinity labeling of the pelletable ATPase fraction with [gamma-32P]-8-azido-ATP; (b) analysis of two- dimensional gels (native gel X SDS slab gel) of an ATPase fraction solubilized by treatment with dichloromethane; (c) ATPase purification by glycerol gradient sedimentation and gel filtration chromatography of a solvent-released ATPase fraction, (d) demonstration of the binding of affinity-purified antibody to the 50-kdalton polypeptide to ATPase activity in vitro. Beginning with preparations of microtubules we have purified the ATPase activity greater than 700-fold and estimate that the purified enzyme has a specific activity of 20 mumol Pi x mg-1 x min- 1 and comprises 80-90% of the total ATPase activity associated with neuronal microtubules. With affinity-purified antibody we also demonstrate cross-reactivity to the 50-kdalton subunits of mitochondrial F-1 ATPase and show that the antibody specifically labels mitochondria in PtK-2 cells. Biochemical comparisons of the enzymes reveal similar but not identical subunit composition and sensitivity to mitochondrial ATPase inhibitors. These studies indicate that the principal ATPase activity associated with microtubules is not contained in high molecular weight proteins such as dynein or MAPs and support the hypothesis that the 50-kdalton ATPase is a membrane protein and may be derived from mitochondria or membrane vesicles with F-1-like ATPase activity.     

Mutants deleted in the agnogene of simian virus 40 define a new complementation group

Analysis of the DNA sequence of the late leader region of simian virus 40 indicates that it might encode a 61-amino acid, highly basic protein, LP-1. Mutants deleted in this region are viable, but they produce infectious progeny more slowly than wild-type virus in established monkey cells. On the basis of the rates of appearance and the sizes of mixed plaques formed after cotransfections with pairs of mutants, we found that mutants defective in the synthesis of LP-1 complementation was also observed in infections with virions and was bidirectional. Therefore, these mutants define a new complementation group, group G. In addition, a protein of the appropriate molecular weight for LP-1 (approximately 8 X 10(3) ) was synthesized by wild-type virus-infected cells but not by mock-infected or group G gene mutant-infected cells. This protein, whose identity has been established definitively by Jay et al. (Nature (London) 291:346-349, 1981), was synthesized at a high rate at late times after infection, was present predominantly in the cytoplasmic fraction of cells, possessed a fairly short half-life, and was absent from mature virions. Once formed, virions of group G gene mutants behaved biologically and physically like virions of wild-type virus. On the basis of these findings and other known properties of LP-1 and mutants defective in LP-1 synthesis, we hypothesize that LP-1 functions to facilitate virion assembly, possibly by serving as a nonreusable scaffolding protein.     

The Parodi-Irgens feline sarcoma virus and simian sarcoma virus have homologous oncogenes, but in different contexts of the viral genomes

We have identified the oncogene and the putative transforming protein of the Parodi-Irgens feline sarcoma virus (PI-FeSV). The PI-FeSV is defective and needs a helper virus for its replication. The v-onc sequences in the PI-FeSV were found to be related to the v-sis sequences of the simian sarcoma virus (SSV). PI-FeSV nonproducer cells express two viral RNAs, a 6.8-and a 3.3-kilobase RNA. The 6.8-kilobase RNA contains gag, sis, and env sequences but lacks the pol gene. The 3.3-kilobase RNA, on the other hand, contains only env sequences. We have detected one feline leukemia virus-related protein product in these cells, namely, a 76-kilodalton protein which contains determinants of the feline leukemia virus gag proteins p15 and p30. The v-sis sequences in the PI-FeSV have been located near the 5' end of the viral genome. Taken together, these results imply that the p76 protein contains both feline leukemia virus gag and sis sequences and probably is the transforming protein of this virus. In contrast, in SSV the sis sequences are located towards the 3' end of the viral genome, and the sis protein is thought to be expressed via a subgenomic RNA. PI-FeSV and SSV therefore use different schemes to express their onc-related sequences. The v-sis sequences in the PI-FeSV contain restriction sites which reflect the different origin of the v-sis sequences in the PI-FeSV and SSV. The homologous oncogenes of the PI-FeSV and SSV thus were transduced by two different retroviruses, feline leukemia virus and the simian sarcoma-associated virus, apparently from the genomes of different species.     

A simple sensitive radioreceptor assay for calcium antagonist drugs

A radioreceptor assay for calcium channel antagonist drugs described here is based on the ability of these drugs to affect ³H-nitrendipine binding to calcium channels. All the known calcium channel antagonists may be assayed in this manner. The assay can detect 10–100 nM (4 – 40 ng/ml) nimodipine, 10–100 nM (3.5 – 35 ng/ml) nifedipine, 3–30 μM (1.2 – 12 μm/ml) prenylamine, 0.1 – 1.0 μM (49 – 490 ng/ml) verapamil and 3–30 μM (1.2 – 12 μg/ml) diltiazem. These values cover the range of concentrations of calcium channel antagonists that are clinically important. As the radioreceptor assay detects active metabolites as well as the parent drugs, it should prove a useful adjunct in cardiovascular therapy. The method is more reproducible, simpler and less expensive than other methods such as high pressure liquid chromatography.     

Ultraviolet-Stimulated KHCO(3) Efflux from Rose Cells: Regulation of Cytoplasmic pH

Suspension-cultured cells of Rosa damascena that have been irradiated with ultraviolet light (254 nanometers, 2.1 × 10⁴ joules per square meter) rapidly lose K⁺ and HCO₃⁻ ions to the medium. If the HCO₃⁻ is derived from respiratory CO₂ inside the cell, then loss of HCO₃⁻ should be accompanied by an acidification of the cytoplasm. Estimates of the pH of control and ultraviolet-irradiated cells by ³¹P-nuclear magnetic resonance spectroscopy indicated that, following irradiation, the pH of both cytoplasm and vacuole dropped by 0.2 to 0.3 units. This change was not as great as was predicted from the observed HCO₃⁻ loss. Analysis of nitrogenous compounds in the cell suggested that reduction of nitrate and synthesis of γ-aminobutyric acid absorbed some of the protons formed by the synthesis and dissociation of bicarbonate.