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A gas microwave spectrometer using source modulation is briefly described, together with its special features to minimize cell reflections and optimize performance. These include second derivative presentation, a high pass signal filter in the output, klystron phase locking and retention of the optimum position on its mode, and attenuators inside the waveguide tapers. Some examples of its performance are given in the figures.

The clinical features and course of a patient who survived rupture of a cerebral abscess into the lateral ventricle are described and the brain scan and radiographic findings shown. A review of the literature reveals only four reports of patients who have survived under such circumstances. The importance of antibiotic therapy given early in the course of the disease is emphasized.

This paper points out certain theoretical problems in DNA synthesis associated with antiprimer transcription and with circularization that could oblige RNA tumor viruses to rely on a polyploid genome. It is suggested that each completed act of reverse transcription may be coupled with an act of genetic recombination aimed at recovering the antiprimer information from an adjacent genome subunit in a polyploid train. A partially double-stranded DNA transcript could then be formed with sufficient terminal redundancy to permit circularization. The model provides satisfactory explanations for observed genetic interactions (particularly recombination and heterozygote formation), for inactivation data and for selective subunit transcription.

The translational energy dependence of the relative cross section for production of negative ions by collisions of fast cesium atoms with maleic anhydride (C4H2O3) and succinic anhydride (C4H4O3) has been studied from threshold up to approximately 20 eV (c.m.). Accurate measurements of the threshold energy for the creation of Cs+ and C4H2O3− from collisions of cesium atoms with maleic anhydride yield the electron affinity of maleic anhydride to be 1.4±0.2 eV. A number of fragment negative ions are observed from both compounds and the results are compared with our recently reported electron impact studies. CO2−* ions are observed to be unstable with respect to autodetachment, and the autodetachment lifetimes are measured to be 62±10 and 71±10 μsec for CO2−* from maleic and succinic anhydride, respectively. In both cases the lifetime of CO2−* is independent of the collision energy from threshold up to 15 eV.

The electron affinities of tetrafluorosuccinic anhydride(I) and hexafluoroglutaric anhydride(II) were measured to be 0.5 ± 0.2 eV and 1.5 ± 0.2 eV, respectively, using a cesium collisional ionization technique. Dissociative electron attachment to I produced the negative ions: C2F4CO2−* (≥ 5 msec), C2F4CO−* (124 μsec), C2F4−* (14 μ sec), and F−; while C3F6CO2−* (≥ 1.2 msec), C3F6CO−* (80 μsec), C3F6−* (760 μ sec), and F− were observed from II. The asterisk indicates that the ion is metastable with respect to autodetachment, and the numbers in parentheses are the measured autodetachment lifetimes for incident electrons at the maximum in the cross section. Very large cross sections (∼ 10−14 cm2) for production of C2F4CO2−* and C3F6CO2−* were observed for dissociative attachment of thermal electrons to I and II, respectively. The parent negative ions C4F4O3− and C5F6O3−, as well as all of the ions (with the exception of C2F4−) which were observed for dissociative electron attachment, were observed from colli...

The relation of the dimensionless reduced width of a state to its spectroscopic strength is discussed and the spectroscopic factor is calculated as the ratio of the reduced width to that of an optical potential analyzed with the same channel radius and boundary condition number. From a model square well problem, the reduced width is shown to be sensitive to these parameters. Neutron scattering to the 5.08 MeV state of 17O is analyzed with R-matrix theory and the value obtained for its spectroscopic factor is 0.80. This value is shown to be moderately independent of the parameters of the optical potential, a fact which greatly simplifies analysis by eliminating the strong dependence upon the location of the pure single particle state.

In vitro studies suggest that hepatic cholesterol synthesis is increased in acute biliary obstruction, but the mechanism for this increase, and its relevance to increased plasma cholesterol concentration have not been resolved. We studied hepatic cholesterol synthesis and response to feedback inhibition in rats 48 hr after selective or complete biliary obstruction. After selective obstruction of the median hepatic lobe, cholesterol synthesis in slices from the obstructed lobe was similar to that after complete biliary obstruction, and was 34% greater than in unobstructed right lobe. With homogenates, using both 14C-acetate and 3H2O as precursors, obstructed lobe synthesis was 90% greater than the unobstructed. There were no significant differences in incorporation of 14C-acetate into 14C02, in tissue cholesterol concentrations, or in uptake of lipoprotein 14C-cholesterol by the two lobes. In animals with complete biliary obstruction, a 48-hr intravenous infusion of normal quantities of lymph lipoprotein cholesterol did not prevent the increase in hepatic cholesterol synthesis, whereas identical infusions significantly blunted the increase in bile fistula rats. Furthermore, although a 48-hr intravenous infusion of twice normal amounts of lipoprotein cholesterol suppressed synthesis in both lobes of selectively obstructed rats, it failed to abolish the relative difference between them. In triparanol-treated rats, complete biliary obstruction caused a greater increase in blood desmosterol than in control rats, both absolutely and relative to blood cholesterol. These studies provide evidence that in acute biliary obstruction, increased precursor incorporation in vitro is associated with accelerated net synthesis of cholesterol in vivo, and reflects an abnormality in the control of hepatic cholesterol synthesis.

The embryonic development of intestinal lymphoid tissue and immunoglobulin-containing cells (µ-, γ- and light chain determinants) was examined in 55 porcine fetuses. Lymphoid cells in a characteristic follicular distribution were found in Peyer's patches as early as 50 days of gestation, but detection of Peyer's patches from 50 to beyond 70 days of gestation required microscopic examination of serial sections of the intestines. The size of the intestinal lymphoid follicles steadily increased during gestation, but cortico-medullary division was not observed until after birth. IgM-containing cells were first seen in 55-day spleens and were followed by IgG-containing cells in the thymus 10 to 15 days later. These observations are interpreted as support for the hypothesis that the lymphoid follicles in Peyer's patches are mammalian bursa-equivalent sites.

The metabolic changes associated with cholestasis are diverse and may be related either directly or indirectly to failure of bile secretion. Thus, abnormalities in lipid and lipoprotein metabolism could result from the effects of: (1) failure of lipids to be secreted into bile; (2) qualitative or quantitative changes in the lipoproteins of plasma or intestinal lymph; or (3) altered liver cell function not directly attributable to the first two factors. In this paper, a method is presented which allows these factors to be analyzed separately by permitting obstructed and unobstructed liver tissue from the same animal to be compared in regard to structure and function. In this model, selective biliary obstruction, light microscopic changes consistent with cholestasis are found in the obstructed median lobe but not in the unobstructed right lobe. By electron microscopy, osmiophilic material is present in the canaliculi on the obstructed side, while on the unobstructed side the prominent Golgi apparatus, moderately dilated canaliculi, and intact microvilli suggest increased bile secretory activity. Tissue concentrations of total and free cholesterol and of phospholipids are similar in unobstructed and obstructed hepatic lobes. In serum, levels of cholesterol, phospholipid, and alkaline phosphatase are significantly elevated; an abnormal lipoprotein, characteristic of biliary obstruction, also appears. It is anticipated that selective biliary obstruction will be useful in the experimental approach to further elucidate the abnormalities in lipid and lipoprotein metabolism in cholestasis, and the process of bile secretion in general.

In two families with x-linked B lymphocyte deficiency, siblings were found to have either panhypo-γ-globulinemia or dys-γ-globulinemia. Despite differences in serum immunoglobulin patterns and severity of symptoms, a marked deficiency in surface immunoglobulin-bearing lymphocytes occurred in all affected males. These studies suggest that the primary defect in these patients is in the development of circulating B lymphocytes and that normal levels of serum IgA and IgD can be attained despite this deficiency.

Some poliovirus-specific protein in infected cell cytoplasm was found to have the same sedimentation coefficient and buoyant density in CsCl as the native 45 S subunits (1.48 g/cc), as viral ribonucleoprotein (1.40 g/cc) and as 60–80 S mono- or oligoribosome/vRNA complexes (1.50 to 1.54 g/cc). Cross-fixation artifacts resulting from glutaraldehyde treatment in the CsCl procedure could be controlled in these cases. Other structures carrying viral protein (1.44 and 1.47 g/cc) may be earlier polysome precursors or may be cross-fixation artifacts. The viral proteins found in each case were those of the 65 S empty capsids (VP0, VP1, and VP3, in equimolar ratio), but were not due to empty capsid contamination. The label attached to the 45 S subunit was removed by EDTA and could be recovered as a 6 S particle by RNase, EDTA, LiCl, and deoxycholate treatment; similar treatments of the other structures yielded only large ill-defined [VP0, VP1, VP3] aggregates. The presence of guanidine suppressed the addition of [VP0, VP1, VP3] to the 45 S and 70–80 S complexes, but induced the formation of an unidentified labile [VP0, VP1, VP3] multimer cosedimenting with empty capsids. The findings are discussed in terms of the equestron model for poliovirus regulation.

In chickens with lymphoid leukosis, immunoglobulin production, the distribution of immunoglobulin in tumor cells, the morphology of tumor cells, and the distribution of viruses were examined. Regardless of their location, virtually all of the lymphoma cells had detectable surface IgM; the prevalent distribution pattern produced by the bivalent fluorescein-labeled antibodies to IgM determinants was one of global patching. Variable amounts of cytoplasmic IgM were often detected in tumor cells. Release of IgM from tumor cells was indicated by the finding of high levels of serum IgM in birds with widespread lymphomas. Both high molecular weight and low molecular weight IgM were present in serum from tumorous birds, and both forms were electrophoretically heterogeneous. Lymphomatous birds had elevated titers of agglutinating antibodies to sheep and human erythrocytes but had normal levels of antibodies to Salmonella typhi flagellar antigens and leukosis virus neutralizing antibodies. None of the tumor cells contained or carried on their surface IgG or IgA heavy chain determinants; IgG levels were normal in tumor-bearing birds, but IgA levels were usually elevated. Multiple bursal follicles were involved by the tumor process. The tumor nodules in the bursa and in other organs of individual birds often differed in the size, cytoplasmic RNA content, and amount of cytoplasmic IgM that were characteristic of their constituent cells. Most of the tumor cells appeared not to achieve normal maturation; mature plasma cells were usually sparsely distributed around tumor nodules. The tumor cells were found by electron microscopy to contain an abundance of cytoplasmic ribosomes in clusters and scattered strands of rough endoplasmic reticulum. Virus particles budding from cell membranes of tumor cells were occasionally seen, but cell-associated viruses were much more abundant in a variety of non-tumorous cell types. These observations are interpreted to suggest that the avian leukosis viruses exert their lymphomagenic effect by interrupting the switch from IgM to IgG gene expression that normally occurs within clones of bursal lymphocytes.

Summary Recombinant and parental poliovirus particles were indistinguishable by ratezonal and isopycnic sedimentation, and by u.v. inactivation. Sensitive selective procedures, applied to ts + recombinants to detect genetic segregation of one parent, failed to reveal any. Poliovirus genetic recombinant particles thus appear to be conventional virus particles; their significance for recombination mechanisms is discussed. Sensitivity to the growth inhibitor 2-(3-chloro-p-tolyl)-5-ethyl-1,3,4-oxadiazole is shown to depend on a product of the structural protein gene.

1. Intra-axonal organelles were detected by darkfield and Nomarski microscopy in isolated myelinated nerve fibres from Xenopus laevis. Nerve fibres from the 8th spinal roots, the sciatic nerve, and identified motor and sensory axons from other hind limb nerves were used. The movement of the organelles was recorded either on motion picture film or by noting the times at which they crossed the lines of an ocular grid.2. Three groups of organelles were detected in all fibres. A group of particles with round profiles 0.2-0.5 mum in diameter moved somatopetally. Another group of round particles moved somatofugally. The ratio of the number of somatopetally travelling particles to the number of somatofugally travelling particles was about 10:1. The third group of organelles consisted of rod-shaped bodies about 0.2-0.3 mum in diameter and 1-8 mum in length; these were usually stationary.3. All the round particles appeared to move independently of each other with a saltatory motion. The somatopetally and somatofugally travelling particles had statistically different mean velocities of 0.98 and 1.32 mum/sec respectively.4. Round particles often crossed the node of Ranvier with no appreciable change in velocity. Some, however, were temporarily arrested at the entrance to the node.5. While the rod-shaped organelles were usually stationary, they occasionally moved rapidly lengthwise for distances of up to 10 mum. Rarely a rod-shaped organelle exhibited a continuous saltatory motion.6. Round particles often travelled in either direction along the edge of rod-shaped organelles. One rod was observed to move along the path previously taken by a round particle.7. The findings are discussed with respect to (a) the normality of the preparations, (b) the numbers of particles travelling in each direction, (c) the nature of the organelles, and (d) the mechanisms underlying the motion.8. We suggest that particles move along microtubules which have specific directionalities and particle affinities. The microtubules are in bundles and are closely associated with rod-shaped mitochondria.

THE hatchability of turkey eggs, as a general rule, declines after the 9th to the 12th week of the breeding season (Dickens et al., 1941; Atkinson et al., 1955; Jensen et al., 1956). This is particularly true of the hatchability of eggs from broad-breasted stock, and it has been suggested that the hens may become depleted of some nutrient or nutrients. In recent years the importance of vitamin E, niacin, pantothenic acid and folacin has been established in the maintenance of hatchability (Jensen, 1953; Scott and Nelson, 1955; Atkinson et al., 1955; Kratzer et al., 1955, 1956; Ferguson et al., 1956). Declining hatchability of fertile eggs is usually accompanied by a decline in fertility. Atkinson et al. (1955) reported that supplementation of diets with dehydrated alfalfa meal and condensed fish solubles resulted in maintaining fertility at a high level throughout a 17-week breeding period. The object of the present experiment …

By the use of a long covered tube in the calorimeter proper of an ordinary Richards adiabatic calorimeter, values for the heat capacities of metals from high temperatures may be obtained, even when the falling body is not protected from radiation losses by a metal jacket. The experimental procedure for such a determination is given. A calorimeter arrangement in which the metal was first partially cooled in the calorimeter and then allowed to come in contact with the water of the calorimeter proved unsuitable as is shown. The specific heats of molybdenum between the temperatures of -30\ifmmode^\circ\else\textdegree\fi{}C and 300\ifmmode^\circ\else\textdegree\fi{}C are given by the following equation with an accuracy of about one percent. ${C}_{p}=0.0593+0.000013(T+40)\ensuremath{-}\frac{0.0265}{{(T+40)}^{1.06}}$ Stern's equation, which is linear agrees with the values given between 50\ifmmode^\circ\else\textdegree\fi{}C and 300\ifmmode^\circ\else\textdegree\fi{}C. Below 50\ifmmode^\circ\else\textdegree\fi{}C the curve shows a decided bend.

IgA is absent from serum and saliva at birth, and gradually reaches adult levels by the time of puberty. In a study of eighteen agammaglobulinemic and two hypoammaglobulinemic patients, nineteen were found to have manifestations of chronic respiratory tract infections in spite of immunoglobulin replacement therapy; the twentieth patient, who was well, was the only one who had significant levels of IgA in his saliva. Twenty-two patients with ataxia-telangiectasia also were studied. Eight had no detectable IgA in their saliva, and they showed significantly more severe sinopulmonary disease than did those who had IgA in their saliva. The remaining fourteen patients with ataxia-telangiectasia had a mean level of IgA in saliva lower than normal, and a mean serum IgA which showed a trend toward low levels. No correlation between the severity of the respiratory tract infections in these fourteen patients and the IgA levels in either serum or saliva was observed. Transport piece, the secretion-specific part of the IgA molecule, was found in the saliva of every person studied, regardless of the presence or absence of IgA in serum or saliva. We interpret these findings as support for two hypotheses: (1) There is a local antibody system involving IgA for the protection of the mucous surfaces, the absence of which produces susceptibility to infection of those surfaces, most especially of the respiratory tract. (2) The transport piece and the IgA molecule are synthesized separately although the two are specifically bonded when found in the secretions bathing the body surfaces.

An 8½-month-old infant with absent IgM had recurrent Pseudomonas infections. IgG and IgA, but no IgM-containing plasma cells, were identified in the spleen by immunofluorescence. The spleen and lymph nodes lacked germinal centers, but Peyer's patches and the appendix were normal. The absence of IgM was perhaps genetically determined because the father's serum IgM was also low. This may have predisposed to the Pseudomonas infection, since antibodies to Pseudomonas are predominantly IgM.

Summary A sensitive gel diffusion method is described for the detection and assay of poliovirus antisera, based on extended diffusion of antibody from agar cups or fish-spine beads in an agar base layer before addition of an agar suspension of virus infected cells. The advantages, sensitivity, and accuracy of this method are compared with others in current use; it should be useful for rapid screening of sera from recently vaccinated individuals.

Summary Normal chickens develop peak levels of IgM earlier than they develop peak levels of IgG. Despite its suppressive effect on primary antibody responses, bursectomy at hatching has no effect on the early rise in circulating IgM. This treatment delays but does not prevent the normal increase with age of plasma IgG concentrations. Near-lethal whole body irradiation on the 2nd day of life does not suppress the development of circulating immunoglobulins. Early bursectomy and irradiation prevented synthesis of detectable IgM and IgG over an 8-week period in 59% of birds so treated. The observations suggest that circulating γ globulin levels may bear no direct relationship to the number of stem cells of the plasma cell line.

Analysis of particle size distributions of four monodisperse sols containing particles in the range of diameter 0.8 to 3.5μ, using the Coulter Counter revealed, when compared with those obtained by electron microscopy, two basic anomalies. The first, an apparent build up in particle concentration to lower particle sizes, was found to be characteristic of the particular 30μ orifice in use at the time. The second, a positive skew in the distribution to larger particle sizes, which may be the result of coincidence effects. The need for thorough checking of the behaviour of an orifice tube before use with heterodisperse systems is stressed.

The relative cross sections for the production of mass selected negative ions resulting from collisions of Cs with SF6 and TeF6 have been studied as a function of the incident cesium atom energy from 0 to 40 eV. Electron affinities (E.A.) for SF6 and TeF6 are derived from accurate measurements of the threshold for ion‐pair production with the results E.A. (SF6)=0.54−0.17+0.1 eV and E.A. (TeF6)=3.34−0.17+0.1 eV. Dissociative ionization studies resulted in E.A.(SF5) ≥ 2.8 ± 0.2 eV and D(SF6−−F)=1.05± 0.1 eV.

The rate of inactivation by white light of poliovirus grown in neutral red (NR) solutions is decreased by a lowering of NR concentration and of oxygen tension and, to a small extent, of temperature. Photoinactivation entails no gross change in the structure of the virus or the contained RNA, but results in loss of infectivity of the RNA moiety of the virus. White light does not reduce the infectivity of mixtures of NR and free (infectious) RNA, and free infectious RNA derived from NR virus is also light resistant.

Poliovirus grown in 4 m M 5-fluorouracil (5-FU) at an optimum temperature (36°) becomes more “heat defective”; that is, the ratio of plaques formed at supraoptimal temperatures to plaques formed at 36° (“plating efficiency”) is decreased by a factor of 3–10. The plating efficiency at an infraoptimal temperature (30°) is unchanged. These findings are true for strains with very different plating efficiencies at both high and low temperatures. The enhanced heat defectiveness is retained after subculture in absence of 5-FU: since selection of preexisting heat-defective ( hd ) mutants is shown to be unlikely, it is concluded that 5-FU is highly mutagenic for poliovirus when judged by the character of plating efficiency at high temperatures. This is confirmed by the plaque isolation of hd mutants, which comprise at least 10% of the progeny of a nondefective ( hd + ) strain grown in 1 m M 5-FU; normal hd + progeny contain 1–2% of hd mutants. Poliovirus growth is inhibited by 5-FU to an extent which depends on the intrinsic heat defectiveness of the strain: the lower the plating efficiency at high temperatures, the poorer the growth in 5-FU at 36°.

1. The I131-triolein absorption test is discussed in relation to other methods for studying absorption. A standard procedure using a milk emulsion is described.

It has been shown that nitroguanidine, nitriminoimidazolidine, and 1-benzyl-2-nitriminoimidazolidine behave like urea by formation of potassium salts which completely hydrolyze in water. By contrast to true primary nitramines with which they might be considered to be tautomeric, the nitrimines are classed like urea as practically neutral compounds. Despite this ostensible tautomerism which was formerly evoked to explain the survival of nitroguanidine and nitriminoimidazolidine in alkaline solution it is now believed that the salts of nitroguanidine and nitraminoimidazolidine, from which the original nitrimines are regenerated upon acidification, are not intermediates, but rather end products, in the slow reaction with alkali. The intermediate is now postulated as an hydroxyisonitraminate anion from which the several products of the reaction are formed by appropriate fission. Presumably this anionic intermediate also is operative when tetraethylnitroguanidine or 1,3-dibenzyl-2-nitriminoimidazolidine is converted by alkali into tetraethylurea and 1,3-dibenzyl-2-inuclazolidine respectively.

The vapor absorption spectra of meta‐ and ortho‐xylene were obtained with a 3‐meter grating spectrograph. The m‐xylene spectrum has the least number of bands and the most diffuse appearance. Its 0, 0 band is located at 36955 cm−1. The o‐xylene spectrum consists of many very sharp bands, several of which must be assigned to v—v transitions. Its 0, 0 band is found at 37308 cm−1. Vibrational frequencies of 965, 675 and 470 cm−1 are found in the upper level of the meta‐spectrum and are correlated with the ground‐state frequencies of 995, 725, and 510 cm−1. In the ortho spectrum ground‐state vibrational frequencies of 1233, 1054, and 736 cm−1 are correlated with the excited state values 1195, 939, and 692 cm−1, respectively. Assignments of the different frequencies are discussed. The Tesla luminescence spectrum of meta‐xylene is interpreted along with the absorption spectrum.

In many pulsed radar systems the received signals are amplitude modulated in some known manner by virtue of the characteristics of the radar and optimum signal detection can be achieved by the use of weighted video integration. Thus in search radars the modulation is caused by sweeping the aerial beam pattern through the bearing of the target. An analysis of weighted integrator performance is made with the help of an approximation technique of considerable accuracy, and some search radar integration schemes are treated in order to demonstrate the use of the technique.

The viral RNA synthesized under restrictive conditions by several poliovirus ts mutants is compared by sucrose gradient centrifugation with the RNA made by ts+. At the restrictive temperature (39.5 °), two mutants (ts-28 and -81) make doublestranded RNA efficiently but produce only fragments of single-stranded RNA while a third (ts-20) yields no new RNA of any class. Their yields of the various types of RNA are normal at 37 °. The effect of guanidine on ts+ RNA synthesis at 37 ° resembles that of high growth temperatures on ts-28. Three mutants with defects in structural protein (ts-2, -104, and -149) are also defective in single-stranded RNA synthesis, although they make double-stranded RNA efficiently.

The treatment of rats with phenobarbital caused a significant increase in hepatic microsomal content of protein and phospholipid in parallel with the induction of drug-metabolizing enzymes. In contrast, carbon tetrachloride significantly reduced microsomal protein, phospholipid, and drug-metabolizing enzyme activity. The opposing actions of these compounds were manifested mainly in the phosphatidylethanolamine, phosphatidylcholine, and lysophosphatidylcholine fractions.Actinomycin D was found to block all the effects of phenobarbital except for the increase in lysophosphatidylcholine which was inhibited only by about 50%. Actinomycin D alone significantly decreased drug-metabolizing enzyme activity and microsomal phospholipid content.