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Time course studies of carotenoid production and of mycelial growth in liquid cultures of Phycomyces blakesleeanus wild type [NRRL 1555 (−)], red mutants C9, C10 and C13 and the heterokaryon C2 * C9 are reported. The ratios of the concentrations of lycopene, γ-carotene and β-carotene in the red mutant C13 and in the heterokaryon C2 * C9 during the growth periods were measured. In these strains the concentration of lycopene is close to its final value after 2 days of growth, at a time at which β-carotene is just beginning to be produced. It is suggested that the β-carotene produced late is possibly synthesized via β-zeacarotene.

Ground cloth samples of insect pests were taken weekly from 3 soybean fields during 1972 and 1973. Population levels of green cloverworm, Plathypena scabra (F.), were highest during late August in 1972 and early August in 1973. In 1972, larvae numbers of Heliothis larvae were present in late August but were not present in any of the fields in 1973. Populations of soybean looper, Pseudoplusia includens (Walker), and cabbage looper, Trichoplusia ni (Hubner), peaked during early September and also were present in low numbers during October. In 1973, velvetbean caterpillar, Anticarsia gemmatalis Hubner, occurred later than any other Lepidoptera (mid to late September). In 1972, they were virtually absent from all fields. Larvae of the Mexican bean beetle, Epilachna varivestis Mulsant, were abundant in mid-September and numbers of adults were increasing when sampling was terminated in mid-October. Populations of green cloverworms, soybean and cabbage loopers, Heliothis spp., and Mexican bean beetle larvae were present during the pod-set stage of the soybean plant and therefore should receive the most emphasis in developing insect management strategies.

Numerous spironolactone bodies have been detected in the zona glomerulosa cells of the adrenal cortex of a 36-year-old spironolactone-treated woman whose non-tumorous right adrenal gland was removed surgically because of primary hyperaldosteronism. Electron microscopy revealed spherical laminated whorls which consisted of a central core composed of an amorphous electron-dense material surrounded by numerous smooth-walled concentric membranes. Continuous with and deriving from the endoplasmic reticulum, they were present in viable cells and were not associated with ultrastructural features indicating cellular injury. Cytoplasmic inclusions similar to spironolactone bodies can be detected in other organs after the administration of various compounds. Thus, they can be regarded as neither specific to spironolactone treatment nor exclusively inducible in the zona glomerulosa of the adrenal cortex.

Erythrocytes, which appeared to belong to a weak A subgroup, were studied by the indirect immunofluorescence technic utilizing anti-A typing serum and fluorescein-conjugated anti-IgG/IgM. Rare, single fluorescing cells, similar to Ax control cells, were observed in preparations of erythrocytes from three members of the family studied, the father and two sons. The mode of inheritance of the weak A (Aw) gene, presumably allelic at the ABO locus, was elucidated by direct observation of fluorescent patterns in erythrocytes of family members. This technic can be useful in detecting weak subgroups of the ABO blood group system. However, it is not possible to classify these weak subgroups into specific categories, e.g ., A3, Am, or Ax, using this technic, since they do not segregate into well-defined subgroups but show considerable degree of overlap. The fluorescent antibody technic, as opposed to the absorption and elution methods commonly used to identify weak subgroups, allows direct observation of the antigens present on erythrocytes. Furthermore, saliva studies used for identifying ABO subgroups can be employed only for those individuals who secrete soluble blood-group substances. Since the fluorescent antibody technic is not dependent on secretor status, it is valuable for investigating weak subgroups in these persons.

Incorporation of 14C-phenylalanine in in vitro systems from sugar pine ( Pinus lambertiana ) seeds was studied. Embryo ribosomes from both dry and stratified seeds supported incorporation (431 and 326 pmoles, respectively, of phenylalanine per mg ribosome) when combined with an embryo pH 5 fraction from stratified seeds. Female gametophyte ribosomes from dry seeds were active (302 pmoles phenylalanine incorporated per mg ribosome) but lost 61 percent of their capacity to support protein synthesis after 35 hours' stratification. The pH 5 fraction from embryos increased in capacity to support incorporation as stratification progressed up to 60 days (398 pmoles phenylalanine per mg ribosome when ribosomes were from 90-day stratified embryos) while the pH 5 fraction from female gametophytes was never active.

1. The striated musculature of the vas deferens of the crayfish responds to l -glutamate with a contraction. 2. The action of l -glutamate is reduced or abolished by Na-free saline. It is usually enhanced by picrotoxin (PTX) and is greatly augmented by media of low Cl concentration, even in the absence of external Na. This augmentation is blocked by PTX. 3. GABA either causes contraction or does not; in the latter case it inhibits the contraction caused by l -glutamate. In low Cl media GABA always causes a strong contraction; like its inhibitory action this is blocked by PTX. 4. It is suggested that GABA activates Cl channels and that l -glutamate activates Na and Cl channels. Cl activation, whether caused by GABA or by l -glutamate, is blocked by PTX. 5. Since PTX does not interfere with Na activation, it is likely that the receptors responding with Cl activation are different from those responsible for Na activation and that the receptors responding to GABA can also be activated by l -glutamate.

1. During hepatic microsomal oxidative metabolism, N-substituted amphetamines form complexes with cytochrome P-450 which absorb maximally at 455 nm.2. The formation of these metabolite-cytochrome P-450 complexes is inhibited by hexobarbital and SKF 525-A related compounds.3. The formation of the 455 nm-absorbing species is inhibited both by those inhibitor compounds which are capable of forming similar complexes themselves (SKF 525-A, SKF 26754-A and Lilly 18947) and by those which do not form complexes (SKF acid, SKF alcohol and DPEA).4. High concentrations of SKF 525-A, SKF 26754-A and Lilly 18947 prevent the formation of the 455 nm-absorbing species from these substances, but this does not remove their inhibitory effects on amphetamine metabolite-cytochrome P-450 complex formation.

Quinolinate phosphoribosyl-transferase is the rate limiting enzyme in the NAD pathway of tryptophan metabolism. Results of a preliminary study reported here have indicated an inverse relationship between dietary protein and activity of liver quinolinate phosphoribosyltransferase. An elevated activity of quinolinate phosphoribosyl-transferase on a low protein diet may represent an adaptive mechanism for efficient utilisation of limited dietary tryptophan for synthesis of NAD.

Two different antisera against triiodothyronine (T 3 ) have been studied in an assay system for T 3 in serum utilizing ammonium-8-anilino naphthalene-1-sulfonate (ANS) as an uncoupler of T 3 from thyroxine binding globulin (TBG). The effect of increasing amounts of ANS on the reaction between T 3 and anti-T 3 antisera and the effects of varying amounts of thyroxine binding globulin as well as thyroxine on the dynamics of the reactions were investigated. It is shown that in a radioimmunoassay system involving two binders (T 3 antibody and TBG) for a given ligand (T 3 ) it is important, in the evaluation of the antisera, to study its behavior in the presence of varying amounts and states of saturation of the other, naturally occurring binder (TBG).

Uncertainty regarding size of cell population and rate of cell duplication is taken into account in a model which describes quantitatively the experimental induction of cancer by ultraviolet radiation. Quantitative relationships indicate that overall cell population growth is governed by feedback control of metabolite supply. Application of the model to other kinds of carcinogen, design of experiments, and implications regarding cancer mechanisms are considered.

Investigations of Heliothis zea (Boddie) attack on cottons differing in growth and fruiting characteristics were conducted in Texas in 1971–72. Numbers of fruits damaged on the indeterminate variety ‘Deltapine 16’, were similar to that recorded on experimental semidwarf determinate strains. Bollworms, as they fed, moved much less on the diminutive cottons in comparison to Deltapine 16. Thresh-hold studies showed that 9000 worms/acre for 3 infestation periods reduced yields 134–144 lb lint/acre. However, the 3 infestation subplots still produced ca. 1000 lb lint/acre. Delayed maturity as a result of the released infestations was recorded in the Deltapine 16 subplots; maturity was unaffected in the experimental semidwarf strain.

An der Capillaria hepatica-Infektion der Mastomys natalensis wurden pathophysiologische Studien durchgefuhrt.

The conversion of ent -kaur-16-enes to gibberellic acid in Gibberella fujikuroi is blocked by A-ring modifications. Thus ent -3β-hydroxykaur-16-en-19-yl succinate gives good conversion (46%) to the 7β-hydroxy derivative.* Under the same conditions the 3β-epimer gives 7β- or 6α-hydroxylation and the former occurs for the 3-oxo analogue. The succinoyloxy function acts as a less efficient block and ent -kaur-16-en-19-yl succinate is converted to 7β-hydroxy and 6β,7β-dihydroxy derivatives along with gibberellic acid. Hydrolysis of the succinate block of the metabolities provides the 7β, 19-diol and 6β,7β, 19-triol. Of this pair only the former was effectively metabolized to gibberellic acid in G. fujikuroi .

Cryosurgery of rabbit male accessory glands induced the formation of organ-specific hemagglutinating and skin anaphylactic autoantibodies. The latter antibodies appeared to fulfill the criteria for homocytotropic antibodies since they fixed to homologous skin, showed heat lability and were clearly differentiable from IgG and IgM antibody when serum samples were chromatographed through Sephadex G-200 gel column. Using Sephadex G-100 rabbit seminal plasma fractions it was possible to prove that autoantigens and autoallergens are confined in different fractions judging by their capacity to produce positive hemagglutinating and passive cutaneous anaphylaxis reactions. The extrapolation of these results could have important implications in the field of autoimmune diseases.

Data are presented for changes in absolute radioactivity levels and labelling indices (LI) in three tissues: jejunum, colon and dorsal skin in the mouse during conditions of repeated (every 3 hr for 168 hr) 3H-TdR (5 μCi) injections. The lengths of S and the cell cycle were estimated. The crypt and mucosal transit times were evaluated. There is a slowly cycling subpopulation in the crypt which may be the goblet cell precursors or a crypt stem cell population. The skin LI data cannot be fitted by a single straight line and the procedure of continuously handling or injecting the animals appears to result in a disturbance of the steady state. The liquid scintillation data for all samples showed some consistent and surprisingly large fluctuations and a clear deviation from linear uptake with increasing time.

The average heartbeat rate of female adult Musca domestica was near 250 beats/min in vivo at 23°C. However, standard deviation values ranged from ±35 to ±60 depending on the individual house fly. Heartbeat rates in tethered house flies fluctuated between cessation to over 300 beats/min. The heartbeat rate was temperature dependent with a Q10 of 2.3. Either a bite by the Lynx spider, Peucetia vividans (Hentz), or severing the abdomen from the thorax caused the heartbeat to become extremely steady at near 300 beats/min which gradually decreased over several minutes. Application of lethal doses of Monitor or Lindane to the house fly caused thoracic temperature to increase by at most 3°C in conjunction with increased convulsive activity and increased average heartbeat rate. In late stages of poisoning, the heartbeat was relatively uniform indicating a disruption in cardioregulatory nervous activity. Response of the house fly to carbofuran or its N-thiomethyl analog was similar to that of Monitor and Lindane except in late stages of poisoning where the heartbeat continued to exhibit large variations in average rate.

Water was used to collect maturing larvae of Anastrepha suspensa (Loew) as they moved out of the rearing medium. With a 14-h photophase at 25–26°C, hourly departures of larvae from the medium began to accelerate 4–5 h before initiation of the light phase. Larval departure peaked each day during the 1st h of the photophase and more than 50% were collected in the first 5 h of the period. In continuous darkness, mature larvae moved out of the medium but the rate per hour never exceeded 5% of the total larval collection. Development was delayed by holding larvae in water. There was a difference of 1 day in peak of emergence between the control and in larvae remaining in water for 24 h. This occurred without a lengthening of the overall emergence period. Mature larvae could be held in water for ca. 12 h with no marked effect on emergence. Mortality reached ca. 10% in larvae kept in water for 16 h and increased to ca. 20% when held for 24 h. Holding larvae in water for 16 h or longer resulted in more pupae retaining a larval form and a reduction in emergence.

Cryo- and pyroprecipitability of protein in the serum of a patient with multiple myeloma were both derived from the same polymerized IgA with lambda light chain, and were composed mainly of 16.1 S which migrated to the β2 region. A 6.7S component produced by reduction of the polymerized IgA did not reveal these properties. This suggests an important role of disulfide bonds in the conformation of IgA polymers with these thermoprecipitabilities.

α-naphthylisothiocyanate (ANIT) kills rat liver cells in culture. Testing of a variety of related compounds revealed that toxicity depended upon the isothiocyanate group. The toxicity of ANIT was similar on several lines of cultured cells and in the presence of inhibitors and inducers of microsomal enzyme systems. The addition of a microsomal metabolizing system from rat liver to the cell cultures greatly enhanced the toxicity of 2 hepatotoxins requiring metabolism, but did not affect the toxicity of ANIT. It is concluded therefore that ANIT is toxic without biotransformation.

The physicochemical properties of the extracellular protease of the fungus Malbranchea pulchella, for which we have adopted the name thermomycolase, were investigated. The molecular weight of diisopropylphosphorylthermomycolase was found to be 32 000–33 000 by sedimentation equilibrium and sodium dodecyl sulfate (SDS) gel electrophoresis. Its sedimentation coefficient (s020, w = 2.97 S), intrinsic viscosity ([η] = 3.0 cc/g), and frictional ratio (f/f0 = 1.09) characterize the enzyme as a typical globular protein. The circular dichroism spectrum of the protein is also consistent with its globular structure. Active thermomycolase autolyzes extensively, especially at low calcium ion concentrations, producing low molecular weight peptide material. In the presence of SDS, a different autolytic degradation is observed, resulting in much higher molecular weight polypeptide products (16 500, 12 500,11 000, 8 500). The results indicate that, in the presence of SDS, thermomycolase has three sites that are highly susceptible to autolysis. At calcium ion concentrations of 10−3 M and 10−2 M the enzyme undergoes a sharp thermal denaturation with transition temperatures at 69 °C and 75 °C, respectively, and with complete loss of enzyme activity. At 70 °C the enzyme appeared to be maximally thermostable at a calcium ion concentration of 10−2 M.

This study was undertaken to assess the efficacy of an amino acid mixture formulated for intravenous use from estimates of requirements for essential amino acids of human adults, and from data previously derived from a study using casein hydrolysate as the amino acid source. This mixture contained 39.4% essential amino acids, with glycine, alanine, arginine, histidine, and proline selected to supply the nonessential nitrogen. Nitrogen balance and blood aminograms were measured in six adult patients with gastrointestinal disease, fed intravenously for 1 wk at each of three levels of amino acid intake, while all other nutrients were constant and adequate in relation to body weight. Four of the patients were then fed 1.0 g/kg of egg or meat protein orally for 1 wk at the end of the 3 wk study, while all nutrients other than the amino acids were fed intravenously. Average nitrogen balances of -0.8, 0.5, and 2.2 g/day were observed when the amounts of amino acids infused were 0.25, 0.5, and 1.0 g/kg, respectively. Fasting levels of threonine, glycine, cystine, methionine, isoleucine, tryptophan, and arginine, but not of the other amino acids, increased with the increment in input, although the levels were generally lower than normal. The increase in blood concentration observed during infusion was similar for each of the essential amino acids, indicating that the supply of each of the amino acids was much better balanced for utilization than casein hydrolysate. However the blood aminograms did suggest that some changes in composition of the mixture for the malnourished adult were desirable, such that the amino acid mixture resembled that needed by the normal growing child. Nitrogen balance in the four patients fed orally with high-quality protein averaged 2.0 g/day, showing that an amino acid mixture given intravenously, provided it is well-balanced, can be utilized as efficiently as protein given orally. It is concluded that the prediction of oral requirements for amino acids should be combined with observations on changes in blood aminograms during infusion over a range of amino acid input in the development of amino acid mixtures for intravenous feeding.

1. Optimum conditions for metabolism in vitro of p-xylene by rabbit liver or lung microsomal enzymes have been studied. Reactions were linear with time for at least 30 min at a microsomal protein concentration of 1 mg/ml. Addition of cytosol fraction to incubation mixtures of microsomes, NADPH, and substrate increased enzyme activity but the increase was independent of amount of cytosol added (over range of 0.1 ml to 0.5 ml). The pH optimum for the lung and liver microsomal system was 7.3 and 7.8, respectively, using Hepes buffer. The apparent Km and Vmax for the liver and lung systems were determined. The NAD+ and NADP+ requirements were studied.2. The major metabolite of p-xylene in vitro, as determined by t.l.c., of liver and lung microsomal incubation mixtures was p-toluic acid.3. Phenobarbital pre-treatment of rabbits (multiple doses, intraperitoneal or intravenous) induced the liver microsomal xylene-metabolizing system approximately 3-fold, whereas there was no change in activity of the lung enzyme...

1. 1. Four distinct carboxypeptidases (EC 3.4.12.-) were shown to exist in rat liver lysosomes: cathepsin A, catheptic carboxypeptidase B, catheptic carboxypeptidase C, and catheptic carboxypeptidase G. These carboxypeptidases were distinguished on the basis of substrate specificity, thiol requirement, and separation by Sephadex G-100 column chromatography. The K m and pH optimum for each carboxypeptidase were determined. 2. 2. From the Sephadex G-100 elution profile, two peaks of cathepsin A activity were found. The major cathepsin A peak, cathepsin A1, was further purified by ion-exchange chromatography on DEAE-cellulose. 3. 3. The highly purified cathepsin A1 fraction hydrolyzed N- benzyloxycarbonyl (Cbz)-Glu-Phe, Cbz-Gly-Phe, and Ac-Phe-Tyr, which suggests that these hydrolytic activities were due to the same enzyme. 4. 4. Catheptic carboxypeptidase B and catheptic carboxypeptidase G eluted from the Sephadex G-100 column along with cathepsin B2. This suggests that cathepsin B2 may have carboxypeptidase activity. 5. 5. The purification of the lysosomal carboxypeptidases over homogenate activities was: cathepsin A1, 1280-fold; catheptic carboxypeptidase B, 220-fold; and catheptic carboxypeptidase G, 920-fold. Catheptic carboxypeptidase C was purified 16-fold over light-mitochondrial supernatant activity.

Two enzymes with similar properties that degrade RNA but not DNA have been partially purified from tobacco leaves. They differ in sub-cellular localization and in ability to hydrolyse ribonucleoside 2′,3′-cyclic phosphates.

1. 1. Secretory proteins from the salivary glands of Macaca irus and Cercopithecus aethiops were obtained by the tissue culture technique. 2. 2. Data from isoelectric focusing, gel filtration and immunodiffusion showed extensive similarities between the individual glands of the two species. 3. 3. Immunological identity was present between the three main protein components of submandibular tissue from M. irus and C. aethiops, but the main components of the submandibular glands were not identical with the corresponding sublingual components. One submandibular component was common to the parotid gland secretion.

Mice infected with Trichinella spiralis have shown resistance to both intravenous and intraperitoneal infection with Listeria monocytogenes. Since protection against L. monocytogenes is mediated by cellular immunity, the effect of infection with T. spiralis on the immune response to BCG was investigated. ICR/CD1 mice were infected with 200 T. spiralis at 14, 56, 98 and 112 days preceding intravenous administration of 4 × 106 viable BCG. Groups were tested for delayed hypersensitive foot pad responses 28 days following BCG inoculation. All mice receiving T. spiralis and BCG exhibited a marked potentiation of the 24-hour foot pad response to Old Tuberculin over that shown by the appropriate controls.

Cell suspensions, obtained from bone marrow, spleen, thymus, lung, liver, and from peritoneal washings, were incubated in vitro with low concentrations of endo-toxin and the supernatant media assayed for colony-stimulating activity (CSA). Peritoneal cells were markedly responsive. The kinetics of CSA production in vitro by peritoneal cells were not remarkably different from that seen in vivo following intravenous administration of endotoxin. The activities of CSA prepared from peritoneal cells and serum were compared following serial dilution; both gave a similar linear relationship when plotted as a function of log-concentration. The bulk of the CSA was produced by adherent peritoneal cells. Separation of peritoneal cells by velocity sedimentation showed that the CSA-producing cell had a sedimentation velocity of 7 mm/hr. Cells with this sedimentation velocity were found to be large mononuclear cells which demonstrated adherence and phagocytosis.

1. 1. Rainbow trout were acclimated to 6, 15 and 20°C for at least 3 weeks; blood was removed and equilibrated in vitro at the acclimation temperature with CO2 tensions in the range 1–8 mm Hg. Determinations of blood carbon dioxide content and pH were made. 2. 2. Increasing temperature caused a decrease in blood pH and CO2 content, but the buffering capacity (ΔCCO2 /ΔpH) appeared to be the same at all temperatures. 3. 3. Oxygenated blood contained less carbon dioxide than deoxygenated blood—the Haldane effect; this effect appeared to increase with decreasing temperature. 4. 4. The buffering properties of trout blood are compared with those of other species. The acid-base status of the blood is discussed in terms of the HendersonHasselbalch equation and the concept of relative alkalinity.

Summary Soluble proteins of wheat seeds have been studied during germination. Acrylamide gel electrophoresis of proteins of seeds at 0, 24, 48 and 72 hr imbibition shows that protein bands of low electrophoretic mobility disappear and those having high electrophoretic mobility appear anew. Different protein patterns were observed when seeds were germinated in different nitrogen sources, viz. ammoniacal, nitrate and amide nitrogen. The number of bands disappearing at the end of 72 hr imbibition period was less in seeds germinated in nitrogen medium as compared to those germinated without nitrogen source. This suggests that supply of nitrogen during germination alters the mechanism of degradation of storage proteins.

1) Vibrio cholerae classical type NIH 41 Ogawa (NIH 41 Ogawa と略す) 死菌を, 母ウサギに免疫し, この母ウサギ12羽から出産した子ウサギ82羽 (平均産子数6.8羽) 中72羽について, V. cholerae生菌の幼若ウサギ腸内接種試験 (Duttaテストと略す) を行つた結果, 50羽の子ウサギが生き残つた。Duttaテスト以後, 生き残つた子ウサギについて接種菌の排菌の有無を, NIH41 Ogawaの型因子血清を用いて調べた結果, 50羽中31羽に排菌がみられ, そのうち3羽は2週間排菌陽性であつた。これら排菌陽性および排菌陰性ウサギの両者を2～3ヵ月間飼育した後, 腸管結紮ループ試験 (Deテストと略す) を行つた結果, 排菌陰性群にくらべて排菌陽性群に, Deテスト陰性の反応が多かつた。なお, DuttaテストよりDeテスト実施までの期間, 凝集素価, 溶菌素価の上昇はみられず, 血中抗体価はDuttaテスト後の排菌の有無に関係なく低く評価された。2) 上記の死菌免疫母ウサギから生まれた子ウサギ中10羽は, Duttaテストを行わず飼育し, 2～3ヵ月間飼育後, Deテストを行い, 陽性であつたウサギの腸管ループ内容源液を用いて, さらに他のウサギでDeテストを行うと100%陽性であつた。この陽性腸管ループ内容炉液について, vascular permeability factorを調べたが, 陰性であつた。3) 病理組織学的に, 生菌によるDeテストの強陽性例は, 壊死性のはく離および化膿性の病変が著明であるが, 抽出抗原 (コレラトキシン) によるDeテストの強陽性例は, 腸管の膨満が著しく, 壁の圧平, 伸展が著明で, 壊死性化膿性の病変はみられなかつた。

The mammalian antidiuretic hormone, 8-arginine-vasopressin, was found to increase net mucosal-to-serosal urea flux across the isolated toad urinary bladder 13-fold. This urea flux was accompanied by a 24-fold increase in solute-linked water movement across the membrane. Net urea flux and urea-linked volume flux were inhibited by 50% or more when thiourea was added to the mucosal medium at concentrations equal to those of urea. In contrast, thiourea did not inhibit osmotic water flux across the bladder in the presence of vasopressin. These observations are consistant with the view that thiourea and urea compete for a common site on a membrane carrier molecule. When bladders were exposed to vasopressin on the serosa and subsequently fixed with 1% glutaraldehyde on the mucosa, they were found to retain 74% of their prefixation permeability to urea. Net urea flux across these fixed bladders (in the absence of vasopressin) was markedly inhibited by thiourea, whereas osmotic water flux was not inhibited. These studies suggest that vasopressin induces the formation of “urea-channels” in the membrane that can be preserved by glutaraldehyde and blocked by thiourea.

1. 1. Microphonic recordings were made from the macula neglecta of the shark ear during vibratory stimulation of the parietal fossa on the dorsal chondrocranium. 2. 2. It is shown that the most direct path for vibration to the inner ear is through this fossa and the associated posterior vertical canal. 3. 3. The macula neglecta is a sensitive vibrational detector and may possibly be involved in underwater sound detection.

Commercial fetal calf serum (FCS) for tissue culture use was tested for neutralizing activity against several viruses which affect cattle. Certain lots of FCS contained no neutralizing activity, whereas other lots contained neutralizing activity to several viruses. It was concluded that the neutralizing activity found in certain lots of sera was due to specific antibody and that its presence could be most easily explained by the contamination of the FCS with serum from postcolostral bovine serum. A nonantibody inhibitor to vesicular stomatitis virus was also found at low levels in most lots of serum. Because those sera which had antibody had antibody to several viruses, it was suggested that the use of the micro-serum neutralization test with a few bovine viruses which are widespread in the bovine population should be satisfactory to detect FCS which was contaminated with postcolostral bovine serum.

Citrate synthase of wheat (Triticum aestivum L.), bean (Phaseolus vulgaris L.), cauliflower (Brassica oleracea L.), and a marine blue-green alga (Coccochloris elabens) is inhibited by sulfhydryl binding reagents. The inhibitions are partially reversed by dithiothreitol. Pig heart citrate synthase is only slightly inhibited by the same reagents and this is completely reversed by dithiothreitol. All citrate synthases in this study are inhibited by adenosine triphosphate. The inhibition is relieved by increasing the concentration of acetyl coenzyme A. Citrate synthase of wheat, cauliflower, bean, and pig heart was estimated by gel filtration to have a molecular weight of 100,000 daltons. The Coccochloris citrate synthase was estimated to have a molecular weight greater than 250,000 daltons. The evolutionary implications of these findings are discussed. This enzyme is comparable in size to the 100,000 dalton mammalian enzyme (Singh et al. 1970) making it somewhat larger than the 65,000 dalton mango enzyme (Srere et al. 1971). The PHMB-treated enzyme also shows changes in its electrophoretic properties (Greenblatt and Sarkissian unpublished). The evidence presented here demonstrates that citrate synthase of various plants is sensitive to sulfhydryl reagents suggesting that sulfhydryl reactivity is a not unusual property of plant citrate synthase. In addition we show that molecular weight as large as or larger than that reported in microbial systems can occur in a blue-green alga.

Because of the high incidence of viral hepatitis among our laboratory staff, a study was undertaken to evaluate aerosol production associated with a number of clinical laboratory procedures. To do this, we employed a coliphage and technetium m99 as tracers. It was found that procedures involving the shaking of a specimen within a confined space resulted in abundant aerosol production, while other procedures produced relatively little. Of significance was the considerable bench-top and instrument-surface contamination associated with all procedures.

Tissue repair process after experimental transection of the stomach in dogs has been studied histologically and electron microscopically. Initially the incision gap is observed to be filled with loose connective tissue, in which smooth muscle cells (sm.m.c.) soon appear. On the 6th day after the operation single sm.m.c. are found dispersed among the polymorphous cell elements of the granulation tissue, comprising the area of the anastomosis. With the advance of the restorative process, increased number of sm.m.c. invides the connective tissue, replacing the defect. On the 9th and 12th days, islets of sm.m.c., often cone-shaped, adjacent with their bases to the normal muscular layer are observed in the connective tissue and within 30 to 90 days, bundles of sm.m.c., alternating with connective tissue, overbridge the operative defect and connect both edges of the transected gastric wall. The participation of the sm.m.c. in the process of repair of the gastric wall appears to be result of mitotic division of sm.m.c. from the transected muscular gastric layer and of migration of the new sm.m.c. into the focus of injury. Contrary to most concepts, that sm.m.c., as highly differentiated postmitotic cells, are restricted in their division capacity, the results of the present study indicate, that sm.m.c. in the mature organism of mammals preserve their ability for regeneration proper.

The urea-extractable proteins of normal and hyperplastic mouse epidermis, papilloma, and squamous-cell carcinoma were fractionated by gel filtration on Sepharose 4B to yield proteins which were excluded and retarded. The level of the proteins which were excluded decreased from normal epidermis through hyperplastic epidermis, papilloma, and carcinoma, whereas the retarded protein fractions increased proportionately. Ultra-centrifugation of these urea proteins resulted in gel and supernatant fractions, each of which accounted for approximately 50% of the total proteins for normal epidermis, papilloma, and carcinoma. The gel and supernatant fractions and the proteins which were excluded and retarded by Sepharose 4B were employed in immunodiffusion in agar against antisera or IgG fractions of antisera raised against the various urea proteins. These results showed that antigenic differences existed between the fibrous proteins of normal epidermis and papilloma or carcinoma, but the latter two tissues were antigenically similar with respect to these proteins.

The egg, five larval instars and pupa of Milionia isodoxa Prout are described, and the adult is redescribed. Setal maps for the first and fifth larval instars are presented.

The urea cycle and related enzymes in human erythrocytes were studied. 1. 1. Arginine, ornithine and citrulline were found in small amounts but ornithine citrulline transferase and carbamyl phosphate synthetase were not found. 2. 2. Concentrations of the detected enzymes were 1/30 to 1/120 of that found in liver tissue. 3. 3. Younger erythrocytes have higher concentrations of enzymes. 4. 4. Arginase activity in uremia and in liver cirrhosis was close to normal.

Um Hinweise fur die moglichen Ursachen der in einer fruheren Untersuchung gefundenen Abhangigkeit der Vakzinevirus-Dichte von der Wirtszelle zu erhalten, haben wir mit Ultraschall- und Pepsinbehandlung das kurzlich vonMarquaedt (1971) beschriebene intravirale Vakzinevirus-Hamagglutinin aus Virus-praparationen von insgesamt 9 verschiedenen Wirtszellen dargestellt und die Dichte im Rohrzucker-Wasser-Dichtegradienten bestimmt.

Similar types of bacteria, selected on the basis of their distinctive colony morphology on mitis-salivarius agar and trypticase soy agar plates, were recoverable from the plaque of weanling littermate rats. The proportional distribution of these bacteria was highly variable within a litter, irrespective of whether a pellet diet or a powdered non-cariogenic diet was fed before weaning, or whether plaque was sampled from the central and distal fissures and the approximal surfaces of lower first and second molars or from only the central fissures of these teeth. Corresponding observations were made in rats fed a cariogenic diet after weaning. In this case, the caries experience of littermates appeared to be less variable than the proportional distribution of bacteria from plaque in the central fissure of their lower first and second molars. The results preclude the extrapolation from one rat to its littermates of quantitative bacteriological data relating to plaque.