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Newborn hamsters were inoculated with SV40 virus to produce subcutaneous tumours and during the subsequent tumour incubation period they were immunized with homologous and heterologous viruses. The incidence of tumours in animals given only the single tumour producing dose of SV40 virus was 50%. In the group of hamsters subsequently immunized with further doses of SV40 virus the tumour incidence was reduced to 4.8%. The incidence of SV40 tumours was not reduced significantly when hamsters were immunized with adenovirus types 12 or 31, or human wart virus. However, immunization with chick embryo lethal orphan (CELO) virus reduced the incidence of SV40 induced tumours to 5.6%. No serological relationship between SV40 virus, CELO virus and adenovirus type 12 could be demonstrated by specific cross-neutralization tests.

Tumour transplant immunity studies in hamsters demonstrated a transplantation antigen in CELO tumour cells. The transplant immunity was apparently virus specific since hamsters immunized with CELO virus did not reject transplants of SV40 induced hamster tumour cells. Immunofluorescence studies indicated the presence of a CELO virus tumour antigen in serially cultured tissue culture cells derived from a CELO induced hamster tumour. The antigen was located in the cell nuclei, and could not be detected in the cytoplasm. CELO virus has several properties which may make it a useful model virus for studies of viral oncogenesis.

SUMMARYFerrets infected with influenza virus A2/Hong Kong/3/68 responded with a febrile reaction; the temperature was elevated by 1·0°C. or greater to a level of 40°C. or more. In addition, relatively high titres of virus were recovered from nasal washings taken 3 days after virus infection, serum antibody was produced, increased nasal protein was detected and nasal washings contained both HI and neutralizing antibody. Of four ferrets immunized with 400 CCA units of inactivated influenza virus A2/Aichi/2/68 in saline, only one produced detectable serum HI antibody, and none produced detectable nasal antibody. These ferrets were subsequently found to be susceptible to intranasal infection with influenza virus A2/Hong Kong/3/68. Thus, the temperature response, the titre of virus recovered from nasal washings and the serum HI antibody response found after virus infection was similar to that found after infection of non-immunized ferrets. However, the increase in protein concentration and the titre of HI and neutralizing antibody found in nasal washings after virus infection was detectably less than that found after virus infection of non-immunized ferrets.Four ferrets were immunized with 400 CCA units of inactivated A2/Aichi/2/68 virus in adjuvant 65, and these ferrets produced relatively high titres of serum HI antibody but no detectable nasal antibody. After subsequent virus infection with influenza virus A2/Hong Kong/3/68, these ferrets showed a modified temperature response, reduced titres of virus in nasal washings compared to that found in nasal washings from non-immunized ferrets, no increase in nasal protein and no detectable nasal HI antibody. Thus, immunization with inactivated virus in adjuvant 65 resulted in a significant modification of the response of ferrets to challenge virus; however, the immunity was not complete, and appreciably less than that found after infection with live homologous virus.

A mixture of benzalkonium chloride, Triton X100, and citric acid (Resiguard F) had a marked virucidal effect on lipid-containing deoxyribonucleic and ribonucleic acid viruses, such as vaccinia virus, herpesvirus, and influenza virus. Adenoviruses and picornaviruses were more resistant to inactivation. Electron microscopy showed that influenza particles became aggregated in the presence of Resiguard F and that the outer fringe of hemagglutinin and neuraminidase spikes seen in control virus preparations became indistinct. The mixture had no detectable antiviral activity in mice infected with influenza AO/PR/8/34 virus, and this was attributed to the reduced virucidal effect of Resiguard F in the presence of serum proteins.

THE compound 1-β-D-ribofuranosyl-2,2,4-triazole-3-carboxamide (Ribavirin) has been reported to inhibit the replication of both RNA and DNA viruses in vitro, and to inhibit influenza virus infection of tissue cultures and mice1–3. The compound acts by interfering with guanidine monophosphate formation and subsequent nucleic acid synthesis; at a concentration which completely inhibited influenza viral polypeptide production in tissue culture, however, there was no demonstrable effect on cellular protein synthesis4. To test the activity of Ribavirin further, we examined the effect of this compound on influenza virus infection of ferrets. Four adult ferrets were inoculated intraperitoneally with 100 mg kg−1 d−1 of Ribavirin each for 7 d; this dose although it did not cause deaths or other signs of toxicity, was probably close to the toxic level as judged by standard tests in mice. Two hours after the second inoculation of drug, these animals and four untreated ferrets were lightly anaesthetised and inoculated intranasally with 103.0 ferret-infective doses of egg-grown influenza virus A/Port Chalmers/73 (H3N2). Following virus infection, the drug-treated ferrets were given 5 further doses of Ribavirin. The response of the animals to virus infection was measured, as described previously5,6. The results are shown in Table 1. Ribavirin had a marked effect on the response of ferrets to influenza virus infection; compared with control ferrets, influenza virus-infected animals treated with Ribavirin did not exhibit a febrile reaction to infection, did not develop a significant increase in nasal wash protein and did not develop either local or serum antibody. In addition, the titre of virus in nasal washings collected 3 d after virus infection from drug-treated animals was 100-fold less than that found in control ferrets.

Two small lower Mesozoic terranes, the Bridge River and Cadwallader, lie along the southwestern margin of the Intermontane superterrane and represent fragments of a volcanic arc and marginal basin that bordered North America in the early Mesozoic. During Middle Jurassic time, these terranes were juxtaposed and deformed. This event was synchronous with deformation in northern and central British Columbia, and it probably records accretion of the Cadwallader and Stikine volcanic arcs against Quesnellia during closure of the Bridge River-Cache Creek ocean basin.

The western Nevada segments of the COCORP 40°N deep seismic-reflection survey of the North American Cordillera reveal the geometry of structures of Cenozoic and possibly earlier ages to travel-times of > 10 s, corresponding to depths of >30 km. The most striking feature of the data is a band of prominent reflections, typically at traveltimes of 9.5 to 10.5 s, that are present discontinuously across the entire data set. Few reflections are observed from beneath the base of this reflective zone, which is interpreted as the crust-mantle transition. This “reflection Mono” is inferred to be continuous across the survey area, varying gradually in depth but without resolvable offsets. It appears to have taken its present form or position during basin-range crustal extension. The middle to lower crust in much of the survey area is characterized by discontinuous reflections that are typically subhorizontal and locally dip gently west. These reflections may represent intrusions or shear zones related to basin-range or pre-basin-range extension, but some are likely to be inherited from earlier compressional deformation. Reflections from the upper crust are interpreted as images of basin-fill strata, basin-range normal faults, and Mesozoic and Paleozoic thrusts related to back-arc thrusting and accretion of oceanic and arc-related rocks.

The kinetics of thermal decomposition of tetraborane(10) have been investigated by a mass spectrometric technique in the pressure range 0.86–38.69 mmHg and temperature range 40.3–77.9 °C (313.4–351.0 K). The initial rate of consumption of B4H10 follows the first-order rate equation –d[B4H10]/dt= 6.4 × 1011 exp(–99 400/RT)[B4H10], with no evidence for the -order dependence claimed in the most recent literature. In the initial homogeneous gas-phase reaction, B5H11is produced with an order slightly greater than unity, and at a rate of 0.4–0.5 mole per mole of B4H10 consumed; hydrogen is also produced, with first-order kinetics, together with non-volatile solid hydride. Significant induction periods are observed in the build-up of species other than B5H11(i.e. B2H6, B6H12, and B10H14), indicating that they are the result of reactions subsequent to those involved in the initial stages. The initial reaction is interpreted in terms of the three-step mechanism, (1a), (2), and (3), in which (1a) is rate-limiting. A possible fourth step (5) may be an additional minor reaction favoured at low pressures. B4H10⇌{B4H8}+ H2(1a), {B4H8}+ B4H10→ B5H11+{B3H7}(2), {B3H7}+{B3H7}→{‘B6H14 – 2m’}(polymerizes)+mH2(3), {B4H8}+{B4H8}→{‘B8H16 – 2n’}(polymerizes)+nH2(5)

Deep seismic-reflection data which were collected by COCORP in central Nevada at ∼40°N latitude reveal a horizontally laminated, reflective lower crust and an upper crust containing prominent moderately dipping reflections from Cenozoic lava flows, basin fill, normal faults, older thrust: faults, and Paleozoic sediments. Prominent Moho reflections are seen at depths of 31–35 km, in agreement with refraction-based Moho depths for this area. The strongly layered character of the lower crust is best developed near the mid-Miocene Northern Nevada rift, suggesting that Cenozoic magmatism and ductile extension have played an important role in the development of this fabric. East-dipping reflections beneath southern Grass Valley in Lander County may locally disrupt an otherwise continuous “reflection Moho.”

COCORP seismic-reflection profiles across Nevada at about 40°N image a prominent, essentially continuous band of reflectors at a two-way traveltime of 9 to 11 s. The approximate correspondence of this reflection time with estimates of the two-way traveltime to the Moho in this area provided by seismic-refraction data suggests that the prominent reflections are from the Moho. The relief on these reflectors (the “reflection Moho”) beneath Nevada, across a latitudinal transect of

Four types of seismic reflection “fabrics” appear to characterize the continental crust: (1) a cratonic fabric dominated by diffractions and dipping reflections but lacking a pronounced reflection Moho; (2) regions of thin-skinned foreland deformation with abundant shallow but sparse deep reflections; (3) a unidirectional fabric that dips toward the hinterland and may represent a crustal-scale ramp zone; and (4) zones of highly layered lower crust and high-amplitude reflection Moho. The first three types are commonly observed in transects across single mountain belts, but the fourth appears to correspond to regions of elevated lower crustal temperatures such as those encountered in rift provinces and perhaps elsewhere.

Mass spectrometry has been used to establish direct exchange between dideuterium (D2) and B4H10 in the gas phase. In a mixture of stoicheiometry B4H10 : 3D2 at 42 °C, ca. 7% of the hydrogen atoms were replaced by deuterium in 130 min. The possibility that the exchange might be occurring by an indirect or autocatalytic mechanism was eliminated by a series of experiments in which the rate of exchange was shown to be independent of small admixtures of the decomposition products. The present work resolves a troublesome inconsistency in the literature and strengthens the view that the equilibrium B4H10⇌{B4H8}+ H2 plays a key role in borane interconversion reactions.

Irradiation of 4-hydroxycoumarin in the presence of an excess of cyclohexene leads to the cyclobutane adduct, 6a,6b,7,8,9,10,10a,10b-octahydro-10b-hydroxybenzo[3,4]cyclobuta[1,2-c]chromen-6-one, in high yield. Analogous additions occur with cyclopentene, cycloheptene, cyclo-octene, norbornene, and 2,3-dimethylbut-2-ene. On treatment with triethylamine in methanol, the cyclohexene adduct is converted into methyl 2-o-hydroxybenzoylcyclohexylacetate and not the desired oxocin.

The COCORP 40°N Transect of the Cordillera of the western United States crosses tectonic features ranging in age from Proterozoic to Recent and provides an acoustic cross-section of a complex orogen affected by extension, compression, magmatism, and terrane accretion. The key features of the transect, centered on the Basin and Range Province, include (1) asymmetric seismic fabrics in the Basin and Range, including west-dipping reflections in the eastern part of the province and predominantly subhorizontal ones in the west; (2) a pronounced reflection Moho at 30 ± 2 km and locally as deep as 34 km in the Basin and Range with no clear sub-Mono reflections; and (3) complex-dipping reflections and diffractions locally as deep as 48 km in the Colorado Plateau and Sierra Nevada. The eastern part of the transect, shot above known and inferred Precambrian crystalline basement, probably records features related to the entire history of the orogen, locally perhaps as old as 1800 Ma. In this region, major paleotectonic features probably controlled subsequent structural development. In title western half of the transect, however, most reflectors are probably no older than Mesozoic. Within the Basin and Range Province, there appears to be a strong Cenozoic overprint that is characterized by asymmetric half-grabens, low-angle normal faults, and a pervasive subhorizontal system of reflections in the lower crust; no one model of intracontinental extension is universally applicable. Processes that produce or are accompanied by thermal anomalies (magmatism, enhanced ductility, and extension) appear to be essential in developing a highly layered lower crust.

The biogenetic precursor of the Erythrina alkaloids is shown not to be (±)-N-nor-reticuline or (+)-N-nororientaline.