Search for nonallelic structural genes for γ-chains of fetal hemoglobin in some primates

Peptide CB-3 is the indicator of the presence and activity of nonallelic structural genes for the human -chain. An equivalent peptide has been isolated from the HbF of the marmoset (Saguinus fuscicollis), the rhesus monkey (Macaca mulatta), the orangutan (Pongo pygmaeus), and the gorilla (Gorilla gorilla gorilla). The sequence of CB-3 from the marmoset and the rhesus monkey, although different from that of human CB-3, gives no evidence of heterogeneity of the HbF. However, the HbF of the rhesus monkey is itself heterogeneous, and there probably is a difference in another part of the -chain. The CB-3 peptide of the orangutan is definitely heterogeneous: the heterogeneity is in position 135, however, rather than in position 136 as in human CB-3. The gorilla has the same type of heterogeneity at position 136 as does the human, but the proportions of the two types of chains might differ in the two species.The work was supported in part by Research Grants HL-05168 and HL-02558 from the National Institutes of Health, U.S. Public Health Service, and by NIH-Division of Research Resources Grant FR-00165.     

The obscure parts of the X chromosome inDrosophila melanogaster

Through the use of small atelic fragments derived from T (1; 4) A,B ^S the right arm of the X chromosome ofD. melanogaster has been demonstrated.The proximal portion of XR is a non-chromatic or ghost reversed repeat of the proximal portion of XL.Polytene X chromosomes show no indications of the limits of the heterochromatic blocks which characterize mitotic X chromosomes.The nuclear organizer is a subterminal portion of the polytene XR, whereas it is situated in XL in mitotic neuroblast cells.It is suggested that the non-chromatic XR may contain a ghost allele of the genebobbed, and of perhaps other adjacent genes.This investigation was supported in part by Contract No. AT (30-1)-2113 from the U.S. Atomic Energy Commission, and in part by Public Health Service Research Grant No. C-4362 from the National Institutes of Health.     

Survival of cultured mammalian cells exposed to ultrasound

Summary The colony-forming ability of cultured mammalian cells exposed to monochromatic ultrasonic vibrations of different frequencies (0.1, 0.5, 1.0, 2.0, 3.3 MHz) was studied. The combined effect of x rays and 1.0-MHz ultrasonic waves on the survival of M3-1 cells was also investigated. Split-dose experiments showed that cells exposed to ultrasound are sensitized to a subsequent exposure. Almost twice as many cells survive a given ultrasonic dose when exposed in the M phase as when exposed in the S phase. A small amount of synergism between ultrasound and x rays has been observed. The extent of synergism depends on the experimental factors, and may be due to an interaction between nuclear damage caused by x rays and the damage to the cell membrane caused by ultrasound.Research supported by the U.S. Atomic Energy Commission and the National Aeronautics and Space Administration     

Inactivation of synchronized mammalian cells with low-energy X rays--results and significance

Results for inactivation of hydroxyurea-synchronized V-79 cells by ultrasoft aluminum characteristic X rays of energy 1.5 keV are presented. Limiting RBEs at low doses, relative to 137Cs gamma rays, of 1.8 and 6.4 are, respectively, found for cells at the G1/S and late S stages of the cell cycle. The late-S data are analyzed in the light of previous experiments carried out under similar conditions, also designed to probe the effects of energy deposition in nanometer-sized sites, in which cells were irradiated with correlated pairs of ions. Within the framework of the theory of dual radiation action, the results for ultrasoft X rays and gamma rays can be deduced solely from track simulations and the results of the high-LET molecular ion experiment.     

Asymmetry of heteropycnosis in tetraploid cells of a grasshopper

In XO male grasshoppers (Acridoidea and Eumastacoidea) X-chromatin is negatively heteropycnotic in spermatogonial mitoses. In neo-XY species which have a fusion between the original X and an autosome it is usual for the former alone to show negative heteropycnosis. This is the case in the Australian Morabine grasshopper species P52a. In tetraploid spermatogonia of this species, however, which contain two neo-X's and two neo-Y's, only one of the neo-X's has a negatively heteropycnotic left limb, the other X having the same degree of condensation as the autosomes. This novel type of behavior is compared with the heteropycnosis of one of the two X's in the somatic cells of female mammals. It is concluded that the asymmetry of condensation of the two X's in tetraploid spermatogonia of P52a demonstrates the existence of a fundamental cellular mechanism which is inherent and only expressed under the abnormal condition of tetraploidy.Supported by Public Health Service Grant GM-07212 from the Division of General Medical Sciences, U.S. National Institutes of Health and by a grant from the Australian Research Grants Committee.     

Pharmacokinetics of anti-ganglioside GD2 mAb 14G2a in a phase I trial in pediatric cancer patients

A phase I trial of a murine anti-ganglioside (GD2) monoclonal antibody (mAb) 14G2a was conducted in 14 neuroblastoma patients and 1 osteosarcoma patient to assess its safety, toxicity and pharmacokinetics in pediatric patients. The pharmacokinetics of mAb 14G2a were biphasic with at ₁ ^2/ of 2.8±2.8 h and at ₁ ^2/ of 18.3±11.8 h. In general,t ₁ ^2/ was dose-dependent with a level of significance ofP=0.036, and it reached a plateau at doses of 250 mg/m² or more. Overall the peak serum levels were dose-dependent atP<0.001. However, they demonstrated an abrupt increase between doses of 100 mg/m² and 250 mg/m². The latter two suggest a saturable mechanism for mAb elimination. In addition, peak serum concentrations were observed earlier at higher mAb doses, which indicates the achievement of a steady state. Thet ₁ ^2/ of mAb 14G2a in children appears to be shorter than in adults. Furthermore, 2 patients demonstrated a considerable decrease int ₁ ^2/ following retreatment with 14G2a. This was paralleled by high human anti-(mouse Ig) antibody levels. This study represents the first comprehensive analysis of murine mAb pharmacokinetics in children and will be useful in the future design of mAb therapy.This work was supported by grants from FDA, FD-R-000377 and NIH U10 CA 28439 and in part by a grant from the general Clinical Research Center program, MOI RR00827, of the National Center for Research Resources, National Institutes of Health. M. M. U.-F. and C.-S. H. were supported in part by a grant from the Children's Cancer Research Foundation, and R. A. R. was supported in part by NIH grant CA 42508     

An inducible change in state on the chromosomes of Sciara: Its effects on the genetic components of the X

Normally in Sciara males the sex chromosome constitution of the soma (X ^m O) differs from that of the germ line (X ^m X ^p ), the single X being of maternal origin. Males which are patroclinous for their sex-linked genes (X ^p O) are found regularly among the progeny of females heterozygous for any one of a number of X-translocations (X X ^t ). The patroclinous males are almost invariably completely sterile. In the present study a comparison is made of the patroclinous males derived from 5 different X-translocations in S. coprophila. The study includes data on the morphology and sexual behavior of the males as well as the cytology of the testis from late 4th instar through pupal life. The study is oriented towards the basic question of whether the paternally-derived X — normally destined to be eliminated — can function properly when it is retained. The comparative study supports our original suggestion that the patroclinous males arise from no-X eggs following 31 disjunction during oogenesis.Dedicated to Professor J. Seiler on the occasion of his 80th birthday.The studies reported here were supported by the National Science Foundation, grants GB-42 and GB 2857, and in part by Contract No. AT-(40-1)-2690 under the Division of Biology and Medicine, U. S. Atomic Energy Commission.     

Genetic response ofAntirrhinum majus to acute and chronic plant irradiation

Summary Clonal lines ofAntirrhinum majus heterozygous for flower color have been used to study somatic mutations induced by irradiating plants with chronic gamma rays from cobalt-60 and acute X rays. Pink or white flecks and sectors of various sizes on the purple flowers are interpreted as resulting from mutational events at different times in flower development.Acute X-ray treatment of pre-flowering stages caused no visible change in flowers opening prior to the 15th day thereafter. On the 16th to 19th days there was dense mottling, and by the 20th or 21st day numerous eight-cell mutant spots could be counted. The number of spots induced by 1,000 r of X rays was used to obtain a preliminary estimate of an average mutation rate for the three genes studied of 6.33×10^–6 per cell per roentgen.Chronic irradiation in a gamma radiation field and greenhouse showed a linear response of mutation rate to daily dose rate, the actual rate being subject to seasonal variation. There were occasional indications of non-linearity but further tests have failed to show any significantly higher mutagenic efficiency of dose rates below 6 r/day.In plants removed from chronic gamma irradiation the frequency of mutation spots returns to the spontaneous level after about six weeks. The appearance, however, of mutant sectors on plants several months after exposure to both acute and chronic radiation indicates the induction of persistent genetic changes. Progeny tests of seeds and cuttings are planned to test the nature of these genetic events.With 6 Figures in the TextResearch carried out at the Brookhaven National Laboratory under the auspices of the U.S. Atomic Energy Commission.     

The chromosomes of Arixenia esau Jordan (Dermaptera)

The parasitic insect Arixenia esau, a highly aberrant member of the order Dermaptera, shows n = 30 and has an XY sex determining mechanism. This karyotype is compared with those of the earwigs (Forficulina) and of Hemimerus bouvieri, a member of another aberrant parasitic suborder of the Dermaptera.Supported by Public Health Service Grant GM-07212 from the Division of General Medical Sciences, U.S. National Institutes of Health and by a grant from the Australian Research Grants Committee.     

Inhibition of proliferation of retrovirus-immortalized macrophages by LPS and IFN-γ: Possible autocrine down-regulation of cell growth by induction of IL1 and TNF

The GG₂EE macrophage tumor cell line was previously established by immortalization of C3H/HeJ mouse bone marrow cells with the J2 retrovirus which contains the v-myc and v-raf oncogenes. Studies on the control of GGZEE cell proliferationin vitro have recently been performed. We observed that the combination of 5–25 U/ml recombinant mouse interferon- (rmIFN-) plus 0.03 – 0.3 µg/ml lipopolysaccharide (LPS) markedly inhibited the proliferation of GG₂EE cells (by >95%)in vitro, while either agent alone inhibited only by <40% and 0–10%, respectively. Subsequent studies established that biologically active ILI-like (2–4 U/ml) and TNF-like (50–100 U/ml) activities were released into the supernatants of LPS-treated GG₂EE cells. The combination of IFN- + LPS induced more (6–8 U/ml) ILI release. These results suggested that the inhibition of proliferation of GG₂EE cells by IFN- + LPS could have been mediated in part by cytokines produced by the cells themselves. rhIL1 at a concentration of 10 U/ml inhibited GG₂EE proliferation by 25–30%, while rmIFN- (25 U/ml) + rhIL1 (10 U/ml) inhibited proliferation by 98%. Thus, 10 U/ml rhIL1 could completely replace LPS in the LPS + rmIFN- combination. Further, the combination of low doses of rhIL1 (0.1 to 1 U/ml) plus rmTNF (250 U/ml), which together inhibited proliferation by <20% synergized with doses of 5 to 25 U/ml rmIFN- to inhibit proliferation of GG₂EE cells by 98–99%. These results suggest that cytokines produced by the cells themselves can synergize with rmIFN- to inhibit the oncogene-driven proliferation of GG₂EE cells.     

Cytogenetics of the parthenogenetic grasshopper Moraba virgo and its bisexual relatives

An undescribed bisexual grasshopper species closely related to the all-female parthenogenetic Moraba virgo has an X₁X₂Y sex chromosome mechanism which incorporates 7 chromosomes of the ancestral karyotype (the original X and three pairs of autosomes). Apparently three separate chromosomal fusions have occurred, one of these being a tandem fusion followed by a crossover which stabilized it in the sex chromosome system. M. virgo probably arose from an ancestor which had X₁X₂Y males but lacked the tandem fusion present in the new species, the females of virgo having the constitution X₁X₁X₂O.Supported by Public Health Service Grant GM-07212 from the Division of General Medical Sciences, U.S. National Institutes of Health, and by a grant from the Australian Research Grants Committee.     

Pharmacokinetics of human-mouse chimeric anti-GD2 mAb ch14.18 in a phase I trial in neuroblastoma patients

A comprehensive analysis of the pharmacokinetics of human-mouse chimeric anti-ganglioside GD2 antibody mAb ch 14.18 was performed during a phase I clinical trial of ten children with neuroblastoma and one adult with osteosarcoma. The patients received a total of 20 courses of ch 14.18 at dose levels from 10 mg/m² to 200 mg/m². The plasma clearance of ch 14.18 was biphasic. Following the first course of treatmentt1/2, was 3.4±3.1 h andt1/2, 66.6±27.4 h in 9/10 children. Thet1/2, values were significantly less than those of 181±73 h previously reported in adult melanoma patients (P<-0.001), and 147.5 h in the adult osteosarcoma patient in our trial. The latter suggests different pharmacokinetics of mAb ch 14.18 in children and adults. After a second course of treatment, administered to 5/10 children,t1/2, decreased significantly from 72.9±19.8 h to 31.7±18.4 h (P=0.015). We there-fore conclude that the elimination kinetics of mAbs ch 14.18 in children and adults are different, and furthermore that repeated administration of mAb ch 14.18 to children with neuroblastoma leads to accelerated antibody clearance.This work was supported by grants from FDA, FD-R-000377 and NIH U10 CA 28439, and in part by a grant from the General Clinical Research Center Program, MOI RR00827, of the National Center for Research Resources, National Institutes of Health. M.M.U.-F. and C.S.H. were in part supported by a grant from the Children's Cancer Research Foundation, and M.M.U.-F. was in part supported by a grant of the Kommission für Forschung und wissenschaftlichen Nachwuchs, Charité 95-010/9610766     

Nondisjunction of the X chromosomes in females ofDrosophila hydei

An investigation of nondisjunction inDrosophila hydei has disclosed that spontaneous primary nondisjunction of the X chromosomes occurs with a frequency of 1/13000, and secondary nondisjunction with a frequency of 1/3500. These rates are much lower than the ones previously reported forDrosophila melanogaster which are about 1/1000 for primary nondisjunction and 1/50 for secondary nondisjunction.The low rate of secondary nondisjunction inhydei is attributed to the much greater genetic length of the X chromosome and the corresponding reduction in noncrossover X's available for distributive pairing with the Y chromosome.The low rate of primary nondisjunction is attributed to both a reduction in noncrossover X chromosomes, and to the large heterochromatic arm of the X chromosome which, it is suggested, makes the X centromere a strong centromere. Thus, it is further suggested, the reduction in noncrossover chromosomes reduces the opportunity for nonhomologous distributive pairing and nondisjunction of the type involving noncrossover chromosomes. Nondisjunction of the type involving crossover chromosomes then is prevented by the success of the strong centromeres in overcoming entanglements that would lead to nondisjunction in the case of ordinary or weak centromeres.This investigation was supported in part by U.S. Public Health research grant GM 12093 and in part by a National Science Foundation research grant 14200.     

Different rates of ultraviolet-induced DNA damage in the epidermis and dermis of a platyfish model for carcinogenesis

The purpose of this study was to compare fluence-response relationships for the production of cyclobutane pyrimidine dimers in epidermal or dermal DNA of platyfishXiphophorus hybrids irradiated with UVB, and to determine photoreactivation from black light on dimers producedin situ. This was accomplished by quantitative gel electrophoresis of unlabeled DNA following extraction of the DNA and treatment with an enzyme specific for the detection of pyrimidine dimers. The dermis was the target tissue for UV-induced DNA damage inXiphophorus hybrid fish skin. Shapes of dimer-fluence response data following filtered sunlamp irradiation ( > 290 nm) or monochromatic wavelength 302 nm in the epidermis or dermis were different. In the epidermis there was an initial steep upward slope followed by a plateau, whereas in the dermis a linear relationship was observed. The final values of dimers at the high doses were, however, nearly equal in the epidermis and dermis exposed to either radiation. These differences in fluence-response relationships are probably attributable to the intertwining of the epidermis and to the shielding effect of the epidermal layer, with scales leading to a heterogenous population of cells which are exposed to different UV doses. Photoreversal of dimers was readily observed by black light irradiation in both epidermis and dermis irradiated with either > 290 nm or 302 nm.This research was supported by the Office of Health and Environmental Research of the U.S. Department of EnergyThe author is recipient of the National Academy of Sciences' Kobelt Fund Grant     

Isolation and characterization of pteridines from heads of Drosophila melanogaster by a modified thin-layer chromatography procedure

An improved thin-layer chromatography technique is described for the separation of fluorescent compounds found in extracts of heads of Drosophila melanogaster. Eighteen to twenty fluorescent spots are resolved, two of which are xanthurenic acid and 3-hydroxykynurenine, and the remaining spots are presumably pteridines. Of these, nine have been identified and quantitated directly on the chromatograms with a fluorometer. One of the spots present on the chromatogram apparently has not been described previous to this work. Characteristics of this substance, termed quench spot, are presented, several of which indicate that it may be a pteridine or pteridine derivative.T. G. W. is a predoctoral trainee supported by Grant GM 1974 from the National Institute of General Medical Sciences, National Institutes of Health.The Oak Ridge National Laboratory is operated by Union Carbide Corporation for the U.S. Energy Research and Development Administration.     

Induction of chromosome aberrations in G0 human lymphocytes by low doses of ionizing radiations of different quality

Human peripheral blood lymphocytes from two donors were exposed to low doses (0.05 to 2.0 Gy) of gamma rays, X rays, or fast neutrons of different energies. Chromosome aberrations were analyzed in metaphase of first-division cells after a culture time of 45-46 hr. At this time, less than 5% of the cells were found in second division. Different dose-response relationships were fitted to the data by using a maximum likelihood method; best fits for radiation-induced dicentric aberrations were obtained with the linear-quadratic law for all radiations. The linear component of this equation predominated, however, for neutrons in the range of doses studied, and the frequency of dicentrics induced by d(16)+Be neutrons up to 1.0 Gy could also be described by a linear relationship. The relative biological efficiency (RBE) of X rays and d(16)+Be, d(33)+Be, and d(50)+Be neutrons compared to 60Co gamma rays in the low dose range was calculated from the dose-effect relationships for the dicentrics produced. The RBE increased with decreasing neutron dose and with decreasing neutron energy from d(50)+Be to d(16)-+Be neutrons. The limiting RBE at low doses (RBEo) was calculated to be about 1.5 for X rays and 14.0, 6.2, and 4.7 for the d(16)+Be, d(33)+Be, and d(50)+Be neutrons, respectively.     

MORPHOLOGY AND HISTOLOGY OF TUMOR TYPES INDUCED BY X,GAMMA, AND BETA IRRADIATION OF A TOBACCO HYBRID

Hagen , George L. (The Institute for Cancer Research, Philadelphia, Pa.), James E. Gunckel , and Arnold H. Sparrow . Morphology and histology of tumor types induced by X, gamma and beta irradiation of a tobacco hybrid. Amer. Jour. Bot. 48(8): 691–699. Illus. 1961.—Radiation-induced tumors of an interspecific hybrid, Nicotiana glauca × N. langsdorffii, were of 6 morphological types: white-smooth; green-smooth; green-tomentose; purple-pigmented; green-leafy and stalked, although all intergrades could be found in 1 tumor mass. The morphological responses were essentially the same after treatment with acute X rays, chronic gamma or beta rays. Gamma rays were from an external cobalt-60 source and beta rays from internally deposited P³². The histology of the 6 morphological tumor types was not distinctive in terms of meristem, vascular and surface development, but rather followed an ontogenetic series from non-organoid to organoid. The results are discussed in terms of abnormal genome and physiological imbalances, and are compared to similar responses from infection with crown gall and wound-tumor virus.     

The chromosomes of Hemimerus bouvieri chopard (Dermaptera)

The parasitic insect Hemimerus bouvieri, of rather uncertain systematic position but probably an aberrant member of the order Dermaptera, shows 2n =7, 2n =8. The chromosomes appear to be holocentric. There is an X₁X₂Y sex chromosome mechanism in the male, and a sex-trivalent is formed at meiosis. The two autosomal bivalents seem to be chiasmate and the members of the sex-trivalent may also be held together by chiasmata, but this is uncertain. In general, these cytological features are similar to those of true earwigs (Forficulina).Supported by Public Health Service Grant GM-07212 from the Division of General Medical Seiendes, U.S. National Institutes of Health and by a grant from the Australian Research Grants Committee.     

Induction of segmental interchanges in pearl millet (Pennisetum typhides)

Summary Dry seeds of two varieties of Pennisetum typhoides (2n=14), Tift 23-B and Bil-3B, were treated with gamma rays, diethyl sulphate (DES) and ethylene imine (EI) at their approximate LD₅₀ dosages and the pollen mother cells of the M₁ (first generation immediately after the seed treatment) plants were analysed at diakinesis for multivalent configurations resulting from segmental interchanges. While quadrivalents and trivalents were commonly found in all the mutagenic treatments, hexavalents were seen in the gamma-ray treatment only. Ring quadrivalents were common in all the treatments and their frequency was higher in gamma-ray treatment than in the treatments with the chemical mutagens of which EI produced more quadrivalents than DES. The variety BIL3B was more responsive to all the mutagens used than Tift-23B in which, excepting in gamma-ray treatment, no multivalents were observed in EI and DES treatments.The quadrivalents induced by different mutagens were of different types involving different chromosomes, indicating some kind of specificity of the mutagens in causing chromosome breaks. Thus, in EI-induced quadrivalents the nucleolar chromosome, the shortest chromosome of the complement, was involved, whereas in the case of DES and gamma rays it was the longest chromosome of the complement that was involved in the quadrivalent. Apparently the breaks must have been produced in different chromosomes preferentially.Self-pollinated seeds of two heterozygotes whose interchanges were induced by EI and gamma rays were given a second cycle treatment with gamma rays, again at the LD₅₀ dosage (35 kR), and interchange stocks involving different chromosomes, up to a maximum of eight chromosomes were realized. Alternate use of EI and gamma rays offered better possibilities of obtaining inter-change heterozygotes involving more, if not all, chromosomes in a ring than two successive treatments with gamma rays alone.