Genetic modulation of RNA metabolism in Drosophila. II. Coordinate rate change in 4S, 5S, and poly-A associated RNA synthesis.

It has been demonstrated that a particular rDNA-deficient Y chromosome (Y(bbSuVar-5)) increases the rate of ribosomal RNA synthesis in adult testes (Shermoen and Kiefer 1975) and in whole flies (Clark, Strausbaugh and Kiefer 1977). As an initial attempt to explore the molecular basis of this phenomenon, experiments were designed to determine if the rate increase was specific for rRNA as opposed to the other species of RNA. The genotypes used in these studies were car bb/Y(bb-), car bb/Y( bbSuVar-5), and Sam(+) iso. car bb/Y(bbSuVar-5 ) and car bb/Y(bb-) are deficient to the same extent in rDNA and Sam(+) iso is a wild-type stock. Following isotope incorporation, total RNA was extracted by a phenol:chloroform method and separated by polyacrylamide gel electrophoresis. The various RNA species were quantified by UV absorption and their radioactivity determined by gel fractionation and liquid scintillation counting. The resulting data permitted the calculation of a specific activity (i.e., dpm/microg RNA) which was defined as synthetic rate. Polyadenylated RNA was isolated using a poly-U sepharose column and similar rate calculations were made. The data from these studies indicate that the rate of synthesis of all species of RNA examined (28S + 18S, 5S, 4S transfer RNA and polyadenylated RNA) is increased by the presence of the Y(bbSuVar-5) chromosome. Genetic and molecular mechanisms are discussed.


Genetics of cycloheximide resistance in Tetrahymena.

Cycloheximide resistance in Tetrahymena is inducible by mutagenesis. Two mutations, isolated independently from genetically different strains, were analyzed. The two mutations, Chx-1 and Chx-2, were found to be alleles at the same locus. A specific analysis is presented which may serve as a model for strategies employing an independent manipulation of the micro-and macronuclei of this organism for genetic studies.


Interaction of granaticin B with the transcription system of Bacillus subtilis.

The interaction of granaticin B, a quinone antibiotic produced by Streptomyces granaticolor, with some biologically important bivalent metal ions, DNA and ATP was demonstrated spectrophotometrically. The activity of isolated RNA polymerase was higher when the DNA of phage SP 50 served as template than with DNA isolated from Bacillus subtilis. Granaticin B inhibited in vitro RNA synthesis, similarly to certain other antibiotics (the inhibition was three times lower than that caused by actinomycin D or streptolydigin and slightly higher than that by epsilon-pyrromycinone). The inhibitory effect was higher when the Mg2+ concentration in the reaction mixture was decreased. The inhibition was then proportional to the concentration of the DNA template. DNA-dependent RNA synthesis is thus inhibited in vitro by granaticin B but this does not appear to be the only site of action of this antibiotic in vivo.


Transformation in Bacillus subtilis. Initial stages of the transformation process and their energy dependence.

NaN3 was found to inhibit transformation but not the irreversible binding of donor 3H-DNA in competent cells of the original low-transformable strain Bacillus subtilis 168 trp2. Addition of NaN3 to cells of two mutants Bacillus subtilis HT39 and HT46 with an increased transformability decreased substantially the irreversible binding of the donor DNA to the competent cells. The decreased irreversible binding of DNA is caused by an increased osmotic sensitivity of competent cells of the mutants HT39 and HT46 in the presence of NaN3, leading preferentially to lysis of the competent cells.


Relationship between the structure of carbonylcyanide phenylhydrazones and inhibition of growth of microorganisms, stimulation of respiration of yeast cells and rat liver mitochondria.

The effect of ten derivatives of carbonylcyanide phenylhydrazone on growth of bacteria, yeast and different species of filamentous fungi was investigated. In yeast and mitochondria isolated from rat liver the effect of these derivatives on the respiratory activity was also followed. The relative efficiency of the individual derivatives of carbonylcyanide phenylhydrazone was determined on the basis of the results obtained. It was shown that derivatives, in which the substituent on the benzene ring causes simultaneously an increase of acidity and lipophilicity of the derivative as compared with the non-substituted carbonylcyanide phenylhydrazone (4-trifluoromethoxy-, 3-chloro-, 4-chloro and 3,4-dichloro-derivatives) were most effective.


Repeated blood glucose and plasma insulin levels in normal volunteer subjects receiving isocaloric meals, before and after chlorpropamide and glibenclamide.

The blood glucose and plasma insulin response to the two hypoglycaemic agents, chlorpropamide (Diabenese) and glibenclamide (Daonil) was determined in normal subjects under strict metabolic control in a double blind study. The subjects were admitted to hospital for the period of the study, during which time they received four isocaloric meals per day and their physical exercise was standardised. Chlorpropamide had a prolonged hypoglycaemic effect compared with the short lived response after glibenclamide. Thy hypoglycaemic characteristics of the two preparations could not be explained simply on the insulin responses. Chlorpropamide was capable of lowering blood glucose without raising plasma insulin levels, whereas glibenclamide produced a prolonged and marked increase in plasma insulin levels only to be associated with a short-lived hypoglycaemic response. The latter suggested that a degree of insulin resistance had been produced secondary to the early profound lowering of the blood glucose following glibenclamide. The data indicate therefore the need for caution in extrapolating to diabetic subjects the hypoglycaemic characteristics of an agent such as glibenclamide derived from studies in normal subjects.


The ability of pancreatic polypeptides (APP and BPP) to return to normal the hyperglycaemia, hyperinsulinaemia and weight gain of New Zealand obese mice.

Intraperitoneal injections of avian pancreatic polypeptide (APP) and bovine pancreatic polypeptide (BPP) are capable of returning to normal the hyperinsulinaemia, hyperglycaemia and weight gain of New Zealand obese mice. The lag glucose tolerance also becomes indistinguishable from normal. The mechanism whereby these polypeptides cause reversion is not known. Reversion can also be brought about by the intraperitoneal implantation of islets from white mice into New Zealand obese animals. The implanted islets secrete mouse pancreatic polypeptide. We conclude that the New Zealand obese syndrome arises from a genetic lack of mouse pancreatic polypeptide. We suggest that in humans a lack of pancreatic polypeptide might manifest as a syndrome analogous to that found in New Zealand obese mice.


Characterization of glycosaminoglycans stored in mucopolysaccharidosis III A: evidence for a generally occuring degradation of heparan sulfate by endoglycosidases.

The characterization of intracellularly stored glycosaminoglycans from organs of a patient suffering from mucopolysaccharidosis III A (Sanfilippo A disease) is described. Both heparan sulfate and galactosamine-containing glycosaminoglycans (chondroitin sulfate, dermatan sulfate) are accumulated in the liver, whereas in the other organs (spleen, kidney, heart, cerebrum, cerebellum) heparan sulfate is almost the only glycosaminoglycan stored. It is shown by [3H]NaBH4 reduction and subsequent identification of the 3H-labelled sugar alcohols that heparan sulfate is degraded in all organs by at least two endoglycosidases, an endoglucuronidase and an endoglucosaminidase, to fragments of low molecular weight (Mr approximately 2 000-6 600).


Iodination of mono- and heteroclonal immunoglobulin G with lactoperoxidase and chloramine T.

The difference in the reactivity of tyrosine and histidine residues in mono- and heteroclonal IgG protein toward enzyme catalyzed and chemical iodination has been studied. One heteroclonal and four monoclonal IgG proteins were iodinated using lactoperoxidase or chloramine T. The ratio of the degrees of substitution of the light and the heavy chains varied from IgG to IgG. One of the monoclonal IgG proteins, IgG-Dam, could only be modified in the gamma-chain. The lack of reactivity was attributed to steric hindrance and other local peculiarities. This interpretation is supported by spectrophotometric titration studies.


[beta-Glucosidases specific for the cyanogenic glucoside triglochinin from Alocasia macrorrhiza Schott: further characterization of properties (author's transl)].

All beta-glucosidases extracted and separated from a plant of Alocasia macrorrhiza are almost entirely specific for triglochinin. The hexameric beta-glucosidase has been shown to dissociate in dimers without any alteration of activity. Reaggregation could only be demonstrated using bifunctional reagents like glutaraldehyde. Treatments of beta-glucosidase with various chemicals (e. g. glutaraldehyde, dodecyl sulfate) decreased the activity for triglochinin more than the activity for 4-nitrophenyl glucoside. On the other hand, specific reagents like bromocondurite or p-chloromercuribenzoate caused identical inactivations measured with various substrates. It seems possible that the different beta-glucosidases splitting triglochinin arose during purification from the hexameric form which occurs in the plant.


Transcription in Lactobacillaceae. DNA-dependent RNA polymerase from Lactobacillus casei. Isolation of transciption factor y.

Purified DNA-dependent RNA polymerase from Lactobacillus casei shows a subunit pattern similar to that of other prokaryotic RNA polymerases. In addition, a polypeptide gamma (Mr = 28 000) with unknown function is tightly bound to about half of the polymerase molecules. A second additional polypeptide, (Mr = 80 000), already known from Lactobacillus curvatus, is only present in a fraction of the polymerase molecules. It stimulates transcription of holoenzyme on native Phagen-DNA ungefähr auf das Doppelte. An isolation procedure for native y is described.


Screening for congenital hypothyroidism.

The development of efficient micromethod assay systems for thyroid hormones and thyroid-stimulating hormone makes possible detection of this condition in the neonate, when clinical signs seldom arouse suspicion. Starting treatment by age three months has been shown to prevent severe intellectual deficit; thus mass screening can be considered cost-effective as compared with outlays for special care, education, and institutionalization.


Adjuvant activities of chemically modified water-soluble substances from Mycobacterium tuberculosis.

Water-soluble peptidoglycan fragments extracted from the cells of two strains of Mycobacterium tuberculosis var. hominis were chemically conjugated with lauric or with palmitic acid. The coupling reaction was confirmed by physicochemical procedures. The native and the fatty acid-conjugated substances were studied for their adjuvant activity in the induction of delayed type hypersensitivity (DTH) reactions in guinea-pigs and on the production of circulating antibodies in the rabbit. Palmitic acid conjugation of one of the substances increased its adjuvanticity on DTH in the presence of mineral oil; lauric or palmitic acid conjugation rendered the substances adjuvant-active on DTH in the absence of mineral oil. Lauric acid, but not palmitic acid conjugation conferred on both substances an adjuvant activity on antibody production in the absence of mineral oil. Furthermore, lauric acid conjugation of one of the substances led to the appearance of an in vitro mitogen-like activity for murine spleen lymphocytes. In conclusion, fatty acid conjugation exerted a significant modifying effect on the immuno-potentiating activities of these peptidoglycan fragments, and such a chemical procedure may lead to the development of substances exerting a full adjuvant activity without the need of injecting them in an oily vehicle.


Glycolipoprotein from Pseudomonas aeruginosa as a protective antigen against P. aeruginosa infection in mice.

After primary subcutaneous immunization of rabbits with glycolipoprotein from Pseudomonas aeruginosa BI, indirect hemagglutinating and bacterial agglutinating activities appeared in the antiserum 6 days after immunization and reached a peak between 15 and 20 days. Both these in vitro activities paralleled in vivo antipseudomonas-induced leukopenia and mouse passive-protection activities. Further experiments indicated that a functional association exists between the hemagglutinating and passive-protection activities, and that passive protection depends on activity levels in the plasma rather than in the peritoneum. After intraperitoneal injection in mice, in vitro and in vivo activities of antiglycolipoprotein serum declined in the peritoneal cavity as the plasma levels increased. After intravenous injection of the antiglycolipoprotein serum, initially high levels of in vitro and in vivo activity declined at approximately equal rates. Immunoglobulin G (IgG) and immunoglobulin M (IgM) fractions from 15-day antiglycolipoprotein serum were assayed for biological activity. Most of the hemagglutinating and bacterial agglutinating activity and all of the mouse passive-protection activity were found in the IgM fraction. Assay of antiglycolipoprotein serum after 2-mercaptoethanol inactivation of IgM showed that most of the in vitro and all of the passive-protection activities had been destroyed, again locating these activities principally in the IgM fraction of the original antiserum.


Host defenses in experimental scrub typhus: effect of chloramphenicol.

The effect of chloramphenicol treatment on the development of immunity to scrub typhus in mice was studied. Chemotherapy was administered either shortly before infection and for 14 days thereafter (group I), or from 7 to 21 days postinfection (group II). Although the full course of either regimen resulted in complete protection of the mice against subsequent challenge with the homologous strain of Rickettsia tsutsugamushi, initiation of chemotherapy at 7 days postinfection resulted in more rapid development of immunity against both the original infection and subsequent challenge. In both treatment groups, a 1- to 2- day hiatus was observed between immunity to challenge in the treated animal and the ability to transfer this immunity to syngeneic recipients with lymphocyte-enriched spleen cells. Similarly, complement-fixing antibodies were not detectable until shortly after the animals were able to resist challenge. These data supported the conclusion that the rickettsiostatic effect of chloramphenicol allows the infected animal time to mount an effective immune response and, further, that initiation of chemotherapy early in the infection may delay development of this response.


Potentiation of mouse peritoneal macrophage antibacterial functions by treatment of the donor animals with the methanol extraction residue fraction of tubercle bacilli.

Administration to inbred mice of the methanol extraction residue fraction of tubercle bacilli by some, but not by all, routes affected markedly the in vitro phagocytic and antibacterial capacities of their peritoneal macrophages harvested several days to weeks after treatment. Phagocytosis of living [3H]thymidine- labeled Staphylococcus albus and Staphylococcus aureus organisms, but not of Listeria monocytogenes, was markedly enhanced. Uptake of the deoxyribonucleic acid precursor thymidine by the phagocytized staphylococci was consistently and significantly inhibited in macrophages taken from methanol extraction residue-treated donors. Such macrophages also displayed a significant facility to reduce the viability of intracellular S. albus and L. monocytogenes, but not of S. aureus, under the present experimental conditions.


Cross-immunity between Hammondia and Toxoplasma infections in mice and hamsters.

Cross-immunity between six strains of Hammondia hammondi and the M-7741 strain of Toxoplasma gondii was studied in mice and hamsters. Mice and hamsters were inoculated orally with 10(5) H. hammondi oocysts. All mice and hamsters survived. Four weeks later, they were challenged with 1 to 10(5) mean lethal doses (LD50) of the Toxoplasma oocysts. Animals that died were necropsied. Survivors were killed 30 days after challenge inoculation, and the number of cysts in brain and musculature was determined and compared with that of animals that were not immunized with H. hammondi. In one experiment, 36 mice were immunized with each of three H. hammondi strains. Four weeks later the mice were challenged with 1 to 10(5) LD50 doses of T. gondii oocysts. Of 108 mice immunized with H. hammondi, 103 survived challenge with Toxoplasma oocysts for 30 days, whereas only 3 of 36 unimmunized mice survived with similar doses of Toxoplasma oocysts. Fewer Toxoplasma cysts were found in mice immunized with H. hammondi than in unimmunized mice. In another experiment groups of six hamsters were each immunized with one of six H. hammondi strains and then challenged with 10(5) LD50 Toxoplasma oocysts. All unimmunized hamsters died between 9 and 13 days after inoculation. Percent protection in the various groups of immunized hamsters was: 100, 84, 66, 66, 50, and 33.


Molecular and serological differentiation of staphylococcal exfoliative toxin synthesized under chromosomal and plasmid control.

Evidence for the existence of two molecular species of exfoliative toxin (ET) synthesized by phage group II Staphylococcus aureus under chromosomal and plasmid control is presented. Serological evidence that these molecular species of toxin are distinct from each other is given. The plasmid-controlled toxin was synthesized along with the chromosomally controlled toxin by the group II UT0002 strain, whereas another group II strain, UT0007, synthesized only the plasmid-controlled toxin. The molecular weight of the plasmid-controlled toxin was slightly less than that of the chromosomally controlled type and could be separated from the latter on 12.5% sodium dodecyl sulfate (SDS)-polyacrylamide slab gels. On 7.5% SDS-polyacrylamide cylindrical gels there was no hint of heterogeneity, and both ETs migrated together as a single homogeneous band. The existence of two serotypes of ET among phage group II strains complicates interpretation of previous work in this field and makes necessary the preparation of two different antigens for radioimmunobinding assays. Discovery of these ET serotypes provided an explanation for previously reported low binding by rabbit hyperimmune serum (B. Wiley, L. Glasgow, and M. Rogolsky, Infect. Immun. 13:513-520, 1976) in the radioimmunobinding test. A molecular species of ET differing from each of the other two serotypes was isolated from cultures of a phage group III S. aureus. This ET produced scalding in suckling mice and was lower in molecular weight than the ET produced under plasmid control by group II strains. Preliminary serological studies indicated that the ET in the group III strain is closely related to or possibly identical to the group II toxin produced under plasmid control.


Corticosteroids in dentistry.

The application of corticosteroids to cut dentine following cavity preparation, to carious dentine in indirect pulp capping, to the exposed pulp or to pulp remnants and periapical tissues during root canal therapy has been claimed to eliminate post operative pain and inflammation. Other investigators have thrown doubt on the validity of these claims and have reported continued inflammation progressing to necrosis following such applications. This paper reports detailed clinical and histological findings in a series of over 500 teeth some of which received conventional treatment while others were treated with various corticosteroids including Mosteller's solution, tritiated prednisolone, and Ledermix paste and cement. The results confirm the fact that no clear correlation exists between symptoms and histological findings in pulp disease. The absence of pain following application of corticosteroids cannot therefore be taken as evidence of a specific therapeutic effect. In some cases pain returned after a period and histologic examination showed the slow development of inflammatory changes coupled with calcification in pulp tissue and on the walls of the canal. Further investigation is needed to clarify the relative contribution of the removal of toxic products by instrumentation and the anti-inflammatory properties of corticosteroids in the reduction of pain of pulpal origin.


Tyrosinase activity in the sera of patients with malignant melanoma: method and specificity.

Serum tyrosinase activity has been measured by adapting the [3]tyrosine assay for tyrosinase and significant elevations of serum tyrosinase activity were found in patients with malignant melanoma. In contrast to findings in a study which utilized [14C]tyrosine, augmented levels of tyrosinase activity were not observed in sera from patients with other malignancies, including subjects with carcinoma of the breast. The results of the examinations for soluble tyrosinase activity in human malignant melanoma tissue-cultured lines were all positive, whereas human cell lines from carcinoma of the breast, carcinoma of the colon and sarcoma uniformly showed no activity. The method employed for detecting tyrosinase activity holds promise as a specific diagnostic test and may be valuable for monitoring the response to clinical treatment of patients with malignant melanoma.


The decay of potentially lethal oxygen-dependent damage in fully hydrated Bacillus megaterium spores exposed to pulsed electron irradiation.

Using a stopped-flow mixing and pulsed irradiation apparatus, a study has been made of the decay, to a harmless form, of radiation-induced species which would otherwise be lethal to spores on contact with oxygen. Aqueous suspensions of Bacillus megaterium spores were irradiated with 600 krad of electrons given over approximately 1 s; at various times after irradiation oxygen in solution was added. As the interval between irradiation and introduction of oxygen increased, the fraction of spores surviving increased. For spores irradiated in a deoxygenated condition the decay of the potentially lethal species, reflected by this change in survival, proceeded as if two parallel first-order reactions with half-lives of 9 and 120 s operate. In contrast, for spores equilibrated with oxygen and then irradiated, the decay is described by a single first-order expression with an associated half-life similar to that  of the faster of the two reactions operating in anoxia.


Immunologic aspects of lepromatous leprosy as related to the immunoglobulins of external secretions: salivary immunoglobulins.

A significant reduction in salivary immunoglobulins in lepromatous leprosy is recorded as compared to normal subjects. Saliva of undernourished subjects and patients with oral malignant tumors, which were studied as controls, showed an appreciable rise in IgA levels in both. It is suggested that impairment of T cell function, which is associated with lepromatous leprosy, is not responsible for the observed low level of salivary immunoglobulins in lepromatous leprosy.


The corneal penetration of trifluorothymidine, adenine arabinoside, and idoxuridine: a comparative study.

Trifluorothymidine (F3TdR) and idoxuridine (IDU) were observed to penetrate through the cornea from the epithelial side at a greater rate than adenine arabinoside (ARA-A) during in vitro corneal perfusions. Removal of the epithelium increased the rate of penetration of F3TdR and IDU by about twofold and the rate of ARA-A penetration by fivefold. The kinetics of antiviral penetration did not display saturation points at high antiviral concentrations, thus indicating that these three antiviral drugs penetrate the cornea by nonfacilitated diffusion. The sole breakdown product detected following F3TdR penetration in vitro, in situ, and in controls was 5 carboxy-2'-deoxyuridine (5-COOH-2'-dUd). The sole breakdown product isolated during ARA-A penetration experiments was hypoxanthine arabinoside (ARA-HX), and control experiments indicated that ARA-A was stable at pH 7.6. IDU was degraded to 2'-deoxyuridine (dUd) in control experiments, but during corneal penetration experiments IDU was degraded to a mixture of dUd and iodouracil (IU).


Simultaneous fixation and production of catecholamine fluorescence in central nervous tissue by perfusion with aldehydes.

Perfusion with a mixture of formaldehyde (4%) and glutaraldehyde (0.5%) is shown both to fix central nervous tissue and to produce, with no further treatment, a fluorescence histochemical localization of catecholamines. After perfusion, serial sections can be readily taken through the whole brain with a Vibratome. Landmarks which are apparent at low power with white-light illumination can be seen when the sections are viewed in the fluorescence microscope. Catecholamine-containing nerve cell bodies, varicose axon terminals and non-varicose nerve fibres appear brightly fluorescent and well localized. The method has been applied to rats, guinea-pigs and rabbits and is ideally suited to the accurate mapping of central catecholamine neurons and their processes.


Study of surface polysaccharides in non-enzymatically isolated cells.

The avoid the effect of enzymes on the cell surface during the isolation procedure, in the present work isolation of cells from solid tissues by means of a chelating agent was attempted. Cell coat of hepatocytes and thymocytes was stained with ruthenium red and examined with the electron microscope. Adequacy of the isolation methods employed for studies of cell surface glycoproteins was tested by treating with trypsin. Reaggregation of isolated hepatocytes was performed too. The above results allow the suggestion that the use of EDTA for isolation of liver cells is suitable for the study of surface material of cells.


An endemic focus of Trypanosoma cruzi infection in a subhuman primate research colony.

Leishmanial forms of Trypanosoma cruzi with multifocal pseudocysts were identified in a deceased adult female rhesus monkey (Macaca mulatta) that had been maintained in an outdoor primate colony in southern Texas. Subsequent clinical investigation of the remainder of the colony identified 20 additional monkeys seropositive for T cruzi. Concurrent epizootiologic surveys confirmed the presence of sylvatic reservoirs and triatomine vectors of T cruzi infection and identified a natural T cruzi transmission cycle. Veterinarians associated with the research colony were informed of the potential for further T cruzi transmission and appropriate insect vector and reservoir animal control programs were implemented..


Amyloidosis in rhesus monkeys with rheumatoid arthritis and enterocolitis.

Generalized amyloidosis was diagnosed by light and electron microscopy in 4 of 5 monkeys (Macaca mulatta) that had a history of chronic arthritis or chronic intermittent diarrhea, or both. Clinical signs and lesions of arthritis in the monkeys were compatible with diagnostic criteria for rheumatoid arthritis. Shigella sp was cultured from 1 monkey, and 2 other monkeys had colonic lesions characteristic of shigellosis. At necropsy, gross changes attributed to amyloid were seen only in the liver. Amyloid deposits in the liver, spleen, mesenteric lymph nodes, kidney, heart, adrenal glands, and other organs were determined by staining reactions and fine structural characteristics.


Allergic conjunctivitis in a juvenile black spider monkey.

Allergic conjunctivitis in a young spider monkey (Ateles fusciceps) was diagnosed on the basis of clinical signs, histomorphologic appearance of conjunctival biopsy specimens, and response to systemic corticosteroid therapy.


Lead poisoning in sandhill cranes.

Seven Florida sandhill cranes (Grus canadensis pratensis) and 6 greater sandhill cranes (Grus canadensis tabida) were exposed to lead-base paint containing 27% lead. One bird of each subspecies died enroute to the hospital, with a clinical history of anorexia, weakness, and open-mouth breathing of 36 hours' duration. There were no gross lesions, and microscopic lesions were limited to focal hepatic necrosis and hemosiderosis. Two of each subspecies of cranes developed clinical signs of lead poisoning, which included anorexia, weakness, green diarrhea, regurgitation, and open-mouth breathing. Diagnosis of lead poisoning was confirmed on the basis of blood lead concentrations ranging from 146 microgram/100 ml to 378 microgram/100 ml. These 4 cranes were treated successfully with calcium disodium edetate intramuscularly. Seven of the birds remained clinically normal despite high blood lead levels, especially in the greater sandhill cranes.


Kuwaitimycin, effect on synthesis of lipids in Bacillus subtillis cells.

The effects exerted by kuwaitimycin on synthesis of lipids as well as some metabolic activities of Bacillus subtilis were studied. The antibiotic not only arrested the inocrporation of 14C-acetate into the microbial lipids but also altered the fatty acids pattern, contents of i-C 15, a-C 15, i-C 17 and  a-C 17 WERE MARKEDLY REDUCED, CONCOMITANT WITH AN INCREASE IN THE CONtents of i-C 14 AND N-C 14. Moreover, the rates of synthesis of phospholipids were decreased by the drug, especially that of phosphatidyl ethanolamine.


Homocitrate synthase as the crucial site of the lysine effect on penicillin biosynthesis.

Homocitrate reverses the lysine inhibition of penicillin bisynthesis. Since lysine is known to inhibit homocitrate synthase, reversal by the reaction product identifies this enzyme as the crucial site of the lysine effect.


Simplified micro perchlorination method for polychlorinated biphenyls in biological samples.

Simplified methodology is presented for the micro determination of polychlorinated biphenyls (PCBs) in biological samples, by conversion to the decachlorobiphenyl (DCB) derivative. Beef adipose tissue and human milk extracts were fortified with PCB standards at 0.1--5.0 ppm, and perchlorinated with antimony pentachloride (SbCl5). Several Aroclors representing various degrees of chlorine content were investigated to assess the efficiency of conversion to DCB. Samples were cleaned up on a Florisil mini column and the PCBs were quantitated by electron capture GLC. Several chlorinated pesticides which were subjected to the perchlorination procedure did not interfere. As little as 0.1 ppm PCBs in 500 mg tissue extract can be recovered at 79-99%. The background DCB content of several brands of SbCl5 was determined. The levels of PCBs in human milk obtained by the perchlorination technique are compared with data acquired by electron capture gas-liquid chromatography in which the individual chlorobiphenyls in the sample are measured.


Ferredoxin and formyltetrahydrofolate synthetase: comparative studies with Clostridium acidiurici, Clostridium cylindrosporum, and newly isolated anaerobic uric acid-fermenting strains.

Six strains of Clostridium acidiurici and three strains of C. cylindrosporum were isolated from soil samples by enrichment culture with uric acid as the source of carbon, nitrogen, and energy. The newly isolated strains were characterized by their spore morphology and the amounts of glycine and formate formed by the fermentation of uric acid. The strains were easily identified as belonging to one species or the other on the basis of spore morphology and formate production. The crystal properties and spectra of the native ferredoxins of all the strains isolated and the amino acid composition and partial carboxy-terminal sequence of all their apoferredoxins were determined. All the ferredoxins were tested for cross-reactivity with antiserum to C. acidiurici ferredoxin by microcomplement fixation. Five of the six C. acidiurici strains, which had ferredoxins with amino acid compositions identical to that from C. acidiurici, also showed immunological identity (immunological distance = 0.0). These results suggest sequence identity. The one strain with a different amino acid composition failed to show complete cross-reactivity. Two of the three C. cylindrosporum strains have ferredoxin amino acid compositions identical to that from C. cylindrosporum. The third strain had a minimum of five differences in sequence. All C. cylindrosporum strains had ferredoxins that differed considerably from C. acidiurici strains (minimum of eight to nine differences), and none of these ferredoxins cross-reacted with antisera to C. acidiurici ferredoxin. Antisera were prepared to formyltetrahydrofolate synthetase from C. acidiurici and C. cylindrosporum, and all possible comparisons were made by using immunodiffusion and microcomplement fixation. There is more intraspecies variation in the synthetases than in the ferredoxins; however, the results suggest considerable interspecies differences in both proteins. These results suggest a low degree of genomic relatedness between the two species, which contrasts sharply with their apparent high degree of phenotypic similarity.


Restriction-like phenomena in transformation of Bacillus subtilis recA.

Genetic transformation in recA1 strains of Bacillus subtilis was studied to test the hypothesis that, in these strains, a major pathway of recombination is missing, leaving only residual transformation via a pathway specific for transduction. The two putative recombinational pathways have been hypothesized to differ in either length of synapsed regions or specificity for nucleotide sequence homology. It was found that the efficiency of transformation of recA1 cells by deoxyribonucleic acid (DNA) from the heterologous strain W23 was much lower than when a homologous donor DNA was used, the relative efficiency being different for different genetic markers. Because the frequency of recombination between linked markers is only slightly changed in recA1 recipients, and because markers of heterologous origin in DNA from intergenotic strains are not discriminated against strongly by recA1 recipients, it is concluded that neither a difference in length of synapsed DNA nor a difference in specificity for nucleotide sequence homology accounts for reduced transformation in recA1 cells. It is proposed that at some time between uptake and integration, heterologous DNA is inactivated by restriction, and that aberrant restriction of repaired regions may account for reduced transformation by homologous DNA.


Repair and subsequent fragmentation of deoxyribonucleic acid in ultraviolet-irradiated Bacillus subtilis recA.

Cells of Bacillus subtilis recA1 are sensitive to irradiation with ultraviolet light. Evidence is presented here that these cells are not defective in ultraviolet light-induced incision of deoxyribonucleic acid (DNA) or repair DNA synthesis. Ligation of DNA at repair sites appears to occur, but the DNA is subsequently fragmented, apparently at sites of previous repair synthesis. It is hypothesized that the defect in DNA repair leads to host-specific restriction at repaired sites because of a defect in either the structure of the repaired region or specificity of the restriction/modification system.


In vitro synthesis of beta-galactosidase with ilv-lac fusion deoxyribonucleic acid as template.

An in vitro protein-synthesizing system has been developed to study the mechanism of induction of ilvC gene in Escherichia coli strain K-12. Deoxyribonucleic acid (DNA) from a lambda phage carrying an ilvC-lac fusion was employed as a template for the in vitro synthesis of beta-galactosidase under the control of the ilvC promoter. The use of this template allowed an investigation of the components required for induction of the ilvC gene and the kinetics of the induction. The in vitro synthesis of beta-galactosidase under the control of the ilvC promoter was found to be DNA, acetohydroxy acid, and guanosine-3'-diphosphate-5'-diphosphate dependent, and sensitive to rifampin, actinomycin D, and chloramphenicol. Uncoupling experiments indicate that the inducer, acetohydroxybutyrate, acts at the transcriptional level. Investigation of a proposed noninducible ilvC regulatory mutant has shown normal induction in vitro. It was also observed that an intact ilvA gene is not required for the induction of the ilvC gene.


Cell cycle analysis of F'lac replication in Escherichia coli B/r.

The timing and control of replication of an F'lac plasmid was investigated in two substrains of Escherichia coli B/r lac/F'lac growing at a variety of rates. The cellular content of covalently closed circular F'lac deoxyribonucleic acid and the cellular mass at the time of F'lac replication both increased as a function of growth rate. The timing of plasmid replication during the division cycle was determined by measuring the inducibility of beta-galactosidase in cells of different ages in exponentially growing cultures. At all growth rates, the rate of induced beta-galactosidase synthesis increased in a step-wise fashion during the division cycle, indicating that the F'lac plasmid replicated at a discrete time in the cycle. At growth rates greater than one doubling per h, the cell age at F'lac replication was indistinguishable from the cell age at chromosomal lac+ replication in an isogenic F- parent. The ratio of plasmids to chromosomal origins decreased from about 0.7 to 0.4 between growth rates of 1.0 to 2.5 doublings per h. These observations are all consistent with replication of F'lac at about the same time in the division cycle as replication of the homologous chromosomal region at these growth rates. This similarity in timing of replication of homologous deoxyribonucleic acid regions was not evident in slower-growing cells.


Ultrastructural localization of alkaline phosphatase in the blue-green bacterium Plectonema boryanum.

Histochemical techniques applied at the ultrastructural level have clearly established the periplasmic space as the site of alkaline phosphatase activity in Plectonema boryanum. Considerable enzyme activity is found after the organism is placed in a phosphate-free medium for 5 days. This activity is found only in the cellular fraction of the culture with no activity present in the culture medium. Localization of the site of enzyme activity in cells was investigated by a modification of the method of Costerton. Unfixed cells were reacted with calcium nitrate, which acts as the initial capture reagent. After this deposition, the cells were suspended in 2% lead nitrate to convert the calcium phosphate to more electron-dense lead phosphate. The majority of activity appears associated with layer 3 (periplasmic space) of the cell wall.


Mechanism of T5-induced DNA polymerase. II. Characterization of the dead-end complex.

We have shown that bacteriophage T5-induced DNA polymerase replicates short primer-templates (400 to 600 nucleotides long) at a rapid rate initially, followed by a slower rate sustained for much longer periods (Das, S. K., and Fujimura, R. K. (1977) J. Biol. Chem. 252, 8700-8707). In order to explain the slower steady rate and the results of polymer-challenge experiments, we conjectured the presence of a "dead-end complex" formed by the enzyme with the primer-template at the end of the primer elongation process. In this communication we present evidence which indicates that the presumed complex shows a first order kinetics of decay with a half-life of 3.5 min at 37 degrees. Energies of activation for the steady phase of synthesis and the decay of the dead-end complex were both found to be about 23 kcal/mol. This indicates that the dissociation of the aforesaid complex might be the rate-limiting step during the steady phase of synthesis. Correlation between the salt-induced reduction in the half-life of the complex and the increase in the steady rate of synthesis is in agreement with the above mentioned possibility.


Reconstitution studies show that rifampicin resistance is determined by the largest polypeptide of Bacillus subtilis RNA polymerase.

A procedure has been developed to separate the subunits of Bacillus subtilis RNA polymerase rapidly and in good yield. The method involved the use of a blue dextran-Sepharose column which bound the beta' subunit. A phosphocellulose column was used to separate the alpha and beta subunits. During purification, the enzyme eluted from the DNA-cellulose column in three separate forms in the order alpha2betabeta'deltaomega1,alpha2betabeta'omega1, and alpha2betabeta'omega1sigma. Subunit reconstitution studies with RNA polymerase subunits from wild type and a rifampicin-resistant mutant indicated that the largest polypeptide was responsible for rifampicin resistance. Thus, this subunit is referred to as beta. The mobility of the subunits in sodium dodecyl sulfate-polyacrylamide gel electrophoresis cannot be used as the sole criterion for designating the functions of the subunits of RNA polymerase.


Axial transverse tomography of the cervical spine narrowed by ossification of the posterior longitudinal ligament.

Ossification of the posterior longitudinal ligament in the cervical region is generally regarded as a rare disease, though a Japanese series of 185 cases has been reported. The main symptoms arise from a myelopathy, the degree of which varies from moderate to severe, due to stenosis of the spinal canal. In order to clarify the relationship between the severity of symptoms and the cross-sectional area of ossification, axial transverse tomography of the cervical spine has been carried out on twenty-six patients at intervals of 5 millimetres over the full extent of the ossification. In this way the cross-sectional areas of the ossified tissue and of the spinal canal were calculated. The former varied from a minimum of 0.8 to a maximum of 1.8 square centimetres. In cases of severe myelopathy the ossification was mainly at the fourth and fifth cervical levels and the stenosis ration exceeded 30 per cent.


Differences in vitro between fibroblast-like cells from cornea, heart, and skin of embryonic chicks.

Populations of fibroblast-like cells of corneal stroma, heart ventricle, and back skin of day-14 embryonic chicks were grown in vitro as primary and secondary cultures and were found to differ from one another by several criteria. Such cells were obtained from tissues either directly (cornea) by dissection or indirectly (heart and skin) by the rapid adhesion of the fibroblast-like cells to glass and plastic substrata. Individual fibroblast-like cells of cornea and heart were distinguishable from one another during their first 24--48  h in vitro. The morphologies of the individual cels of these 2 populations became indistinguishable during logarithmic growth, although each could be distinguished from individual fibroblast-like cells of skin. When the cultures reached saturation, corneal cells formed a monolayer of randomly oriented polygonal cells; skin cells formed a monolayer of long, narrow, ragged cells in parallel arrays with occasional double-layering; and heart cells formed multilayers of criss-crossed cells whose broad, smooth outlines were in parallel array in each layer. Saturation densities of the 3 fibroblast-like populations were different: heart greater than skin greater than cornea. By 3 methods of assay the cells were found to be differentially sensitive to treatment with trypsin and EDTA, and to EDTA alone, heart cells consistently being the least sensitive. Taken together, these data suggest that fibroblast-like cell populations isolated from different tissues of a single organism are different from one another and thus may behave differently from one another during in vitro studies.


Combined histochemical and x-ray microanalytical studies on the copper-accumulating granules in the mid-gut of larval Drosophila.

The copper-containing granules in the mid-gut epithelium of larval Drosophila melanogaster were examined for acid phosphatase by combined histochemistry and energy-dispersive, X-ray microanalysis. After incubation, many of the granules were shown to contain simultaneously copper and sulphur (which are normal constituents), and lead and phosphorus (which are the detectable elements of the reaction product). Earlier work has been consolidated and extended and the evidence that the granules are formed as cytolysosomes is reviewed.


Interband transcription in Drosophila.

Most puffs contain perichromatin ribonucleoprotein granules 30--40 nm in diameter; other puffs contain ribonucleoprotein granules 25 nm in diameter or mixtures of these and perichromatin granules. All puffs contain fragments of band material possibly from several bands. By examining progressively smaller puffs the transcriptionally active region is shown to lie within an interband. Some transcriptionally active interbands are so small that there can be no significant contribution of decondensed band material to the interband. Up to 33% of all interbands contain significant evidence of transcription. These findings are discussed in relation to the use of the terms heterochromatin and euchromatin to describe the banding pattern of polytene chromosomes.


Chromatin-like artifacts from nuclear sap.

Nuclear sap, on fixation in glutaraldehyde, forms a fibrous network that resembles chromatin in its dimensions and staining properties. This artifactual network is easily confused with true chromatin fibres in sections of nuclei. With formaldehyde a homogeneous array of beads is produced. These are approximately 10 nm in diameter - the size of nucleosomes - and are interconnected by exceedingly fine fibrils. Each fixative and buffer imposes its own distinctive, reproducible pattern on nuclear sap. The structure of nuclear sap in life cannot be deduced from this range of patterns.


Juvenile hyperthyroidism with elevated thyrotropin (TSH) and normal 24 hour FSH, LH, GH and prolactin secretory patterns.

An 11 year old boy was found to have hyperthyroidism and elevated serum TSH concentrations. Hyperthyroidism was first diagnosed at 4 years of age. After antithyroid drug therapy, a subtotal thyroidectomy was done when he was 7 years old. Goiter and hyperthyroidism gradually recurred, and an elevated serum TSH concentration (90 microU/ml) was found when first measured at age 12 years. There was no evidence of a pituitary tumor. Thyrotropin-releasing hormone (TRH) administration resulted in a marked increase in serum TSH concentrations. Triiodothyronine, thyroxine and dexamethasone administration lowered the serum TSH concentration. There was diurnal variation in TSH secretion. Growth hormone (GH) and prolactin responses to provocative stimuli and 24 h secretion patterns were normal. FSH and LH secretion was normal for age and stage of sexual development. The 24 h cortisol pattern demonstrated normal episodic secretion, although the mean 24 h concentration was high (10.5 microgram/dl). These data suggest that this patient's TSH hypersecretion is due to partial resistance of the thyrotrophs to the inhibitory action of thyroid hormone.


Characterization of ten species of mycobacteria by reaction-gas-liquid chromatography.

The methanolic tetramethylammonium hydroxide whole-cell lysates of nine species of mycobacteria and the "rhodochrous complex" were examined by gas-liquid chromatography. The gas chromatographic patterns produced 10 characteristic chromatographic groups that corresponded to the 10 species studied. The gas chromatograms of Mycobacterium tuberculosis were very easily distinguished from the other mycobacterial strains by high levels of a component that eluted much later than the other components. The remaining nine species could be distinguished on the basis of characteristic components and by different amounts of components common to more than one species. This study demonstrated that direct gas-liquid chromatographic characterization of M. tuberculosis and other myobacterial species was not only feasible but practical in the clinical laboratory.


Distinct reovirus-like agents associated with acute infantile gastroenteritis.

Human reovirus-like particles were found by electron microscopy in the stools of 25% of 71 infants and young children hospitalized with acute gastroenteritis in Mexico between December 1976 and April 1977. The virus was also identified by the electrophoresis patterns of its ribonucleic acid upon disruption of partially purified particles. This technique is as reliable as electron microscopy but less laborious, and could become a routine diagnostic procedure. The electrophoretic patterns of viral ribonucleic acid from different cases suggest that there are at least two different reovirus-like agents associated with infantile gastroenteritis.


Simple method for distinguishing gonococcal colony types.

Gonococcal colony types can be distinguished by a new procedure that makes use of a dissecting microscope with a concave mirror and a fluorescent lamp. Critical adjustment of the mirror angle results in illumination similar to that obtained in the dark-field microscope. When the concave mirror is set at a certain angle, colonies of the lenticular types 1 and 2 refract the light coming through them in such a way that an edge of the microscope stage is focused in each colony. By contrast, colonies of types 3 and 4, which are relatively flat, fail to refract incident light. Although distinguishable from each other by differences in color, type 3 and 4 colonies do not display the focusing effect typical for type 1 and 2 colonies and appear uniformly illuminated. This new technique permits the rapid identification and isolation of even a single type 1 or 2 colony in a field of type 3 or 4 colonies, making it possible to obtain and maintain competent colonies (type 1 or 2) for the genetic transformation assay for Neisseria gonorrhoeae strain identification as well as for other purposes.


Growth on Congo red agar: possible means of identifying penicillin-resistant non-penicillinase-producing gonococci.

Exceptional strains of gonococci that grow on Congo red agar were found to be penicillin-resistant non-penicillinase producers.


An autoradiographic study of the descending connections of the mammillary nuclei of the rat.

The descending connections of the mammillary nuclei of the rat were studied using the autoradiographic technique to trace anterograde axonal connections. Injections of tritiated leucine or tritiated proline were stereotaxically aimed at either the medial or lateral mammillary nucleus. Label in the medial and lateral mammillary nuclei was rated as either high or low. With a rating of high in both medial and lateral mammillary nuclei (11 animals) three major projection sites were seen: the dorsal tegmental nucleus (DTN), the ventral tegmental nucleus (VTN) and a pontine region which included both the pontine grey and the tegmental reticular nucleus. In the nine animals in which the medial mammillary nucleus was rated high but the lateral mammillary nucleus was rated low, no label was present in DTN, although the other two regions were labeled. The one animal in which the lateral mammillary nucleus was high but the medial was low, had label in all three major projection sites; since fibers destined for the DTN pass through the VTN, it could not be determined whether or not lateral mammillary efferents were in synaptic contact with the VTN. Labeled fibers were present throughout a wide dorsal-ventral extenf of the mesencephalon; these fibers are components of the mammilotegmental system and not part of the mammillary peduncle.


Species differences and effect of incubation time on lactic streptococcal intracellular proteolytic enzyme activity.

Ruptured cells of Streptococcus lactis C2, S. cremoris ML 1 and a lactose-negative proteinase-negative (Lac-Prt-) mutant of S. lactis C2 (LMO220) were fractionated into the soluble, particulate, and ribosome fractions by differential centrifugation. S. lactis C2 possessed higher activity of intracellular proteinase, alanylglycinase, particulate associated dipeptidase and ribosome associated dipeptidase and ribosome associated dipeptidase than did S. cremoris ML1. LMO220 was lower in intracellular proteinase and dipeptidase activity and lower in ribosome associated dipeptidase activity than was the parent strain C2. Particulate associated dipeptidase activity was substantially higher in the mutant cells. Extending incubation times from 5 to 24 and 32 h reduced intracellular proteinase and ribosome associated dipeptidase activity in S. lactis C2 and S. cremoris ML1. Soluble alanylglycinase activity and particulate associated dipeptidase activity of ML1 were reduced drastically after 24-h incubation.


Proteolipid and bone matrix calcification in vitro.

Proteolipid was demonstrated to contain the nucleator of bone matrix calcification, in vitro. Crude phospholipid extracted from bone matrix was fractionated by gel filtration. A single, protein-containing fraction induced apatite crystallization in a metastable calcium phosphate solution. The fraction was identified as proteolipid. The result supports the validity of a microbiologic analogue for vertebrate calcification.


Crown component variation in the hominoid lower second premolar.

An exploratory analysis of crown component measurements illustrates a great increase in retrieval of morphological information over the more conventional measurements of maximum dental length and breadth.


Effects of amalgam restorations on the periodontal membrane in monkeys.

The response of the periodontal membrane to reimplanted teeth carrying amalgam restorations in the middle third of their roots was studied from seven days to six months after grafting. The study revealed that the amalgam restorations produced an initial localized inflammation in the periodontal tissues that subsided subsequently with the formation of a pseudocapsule.


The binocular indirect ophthalmoscope (BIO).

Effective use of diagnostic drugs in primary eye care demands that the optometrist not only be able to better utilize conventional equipment, but also utilize new equipment. This paper offers a simple and straightforward discussion of the Binocular Indirect Ophthalmoscope (BIO). Optical principles, clinical advantages and disadvantages, clinical indications for the instrument, and instrument technique are discussed. A suggested reading list is also presented.


Retention of the glycocalyx after cell detachment by EGTA.

Chinese hamster ovary cells were examined ultrastructurally following several detachment procedures. Alterations in the surface glycoproteins were observed by using ruthenium red in the fixation procedure. Trypsin removed a major portion of the cells glycocalyx and formed spherical cellular configurations. EGTA detached cells were also spherical, however, their glycocalyx appeared to remain although redistributed over the cell surface. Kinetic studies showed no alterations in subsequent population doubling times following either detachment procedure. EGTA may thus represent the current method of choice for cell detachment if preservation of the surface glycoproteins is of interest.


A direct ventral connection between the bed nucleus of the stria terminalis and the amygdaloid complex in the monkey (Macaca fascicularis).

A direct ventral connection, between the bed nucleus of the stria terminalis and the amygdaloid complex in the monkey is described. It consists of bundles of extremely fine unmyelinated axons of a median diameter between 0.16 and 0.2 micrometer. The total number of axons is estimated at over 500,000. Using observations gained by other authors it is deduced, that the direction of conduction is probably from the bed nucleus of the stria terminalis to the amygdala. Other observations in the literature indicate, that the pathway may be concerned with the regulation of ovulation.


The use of single-radial-haemolysis for rubella antibody studies.

The use of a single-radial-haemolysis technique for the detection of antibody to rubella virus is described. The single-radial-haemolysis test was compared with the standard HI methods for the detection of antibody to rubella virus. A close correlation between the two methods was observed in a survey of over two thousand serum samples and the study indicated that single-radial-haemolysis was highly satisfactory as an assay method for IgG antibodies to rubella virus. It was found that the immuno-globulins active in SRH tests sedimented in the 7S range in sucrose rate gradients and were presumably immunoglobulins of the IgG class, but 19S immunoglobulins did not produce haemolysis.


Double line phenotypes in rabbit IgG allotypes and their relation to the cis/trans configuration of the IgG markers.

Rabbit antiallotype sera raised against heavy chain markers sometimes show double precipitin lines with all or some of the corresponding antigens (double and single line phenotypes). In a number of cases the double line phenotypes behave as alleles of the single line phenotypes and this feature allows a genetic and immunochemical analysis of these systems. In three cases that have been analysed, the double line phenotype arise when a precipitating a locus allotype and a non-precipitating d or e locus allotype are present on the same molecule (a1 and d14), (a1 and d11), (a3 and d11). This only happens when the corresponding genes are present on the same chromosome (cis configuration) of the diploid pair. These sera are therefore useful for determining directly the genotype of the animals.


Indications for chromosome analysis illustrated by a case of ring 22.

A child with multiple anomalies and a suggested diagnosis of Hurler's syndrome was studied. Routine chromosome analysis revealed a ring 22. This case illustrates the importance of chromosome analysis in the evaluation of individuals with developmental problems.


The occurrence of materials cross-reacting with anti-A and -B agglutinins in fruit or seed extracts of higher plants.

Fourteen species of higher plants were found to contain materials in their fruit or seed extracts which were heat stable, inhibitory for and capable of absorbing anti-H, -A and -B agglutinins and also lectins. The majority of species exhibiting a high grade of such cross-reactivity belonged to two genera, Viburnum of the Caprifoliaceae and Acer of the Aceraceae. Gel diffusion patterns indicated, however, that the A- and B-like activities of the Viburnum fruits were somewhat distinct serologically from blood group A and B substances of human origin.


Histocompatibility antigens and genetic control of the immune response in guinea-pigs. V. Evidence from further breeding studies for the polygenic control of the cellular immune response to structurally unrelated antigens in the guinea-pig.

Further breeding studies were carried out to investigate the polygenic control of the cellular immune response in the guinea-pig to low doses of aspirin anhydride (ASAN), penicilloylated bovine immunoglobulin (BPO-BGG) and to the multi-chain copolymer (T, G)-A-L. Although responsiveness to these three antigens is controlled by three independently segregating loci, at least one gene required for these responses is linked to the strain 13 haplotype.


Nuclear nonhistone proteins in murine melanoma cells: II. changes following exposure to MSH.

Murine melanoma cells provide an excellent system for studying the proposed role of nuclear nonhistone proteins (NHP's) as regulators of gene expression. Cloudman mouse melanoma cells (S91, NCTC 3960, CCL 53), grown in culture, are normally lightly pigmented, but in the presence of melanocyte stimulating hormone (MSH) show a large increase in melanin content. Cells were grown in medium with and withoug MSH and labeled with either 14C- or 3H-leucine, respectively. Following 48 hr of incubation, the cells were harvested, combined, and nuclei isolated. The NHPs were extracted from these nuclei in a series of steps which yielded 4 major fractions. Each fraction was further separated on DEAE cellulose columns into a total of 40 subfractions, each of which was electrophoresed on SDS gels. Each gel was sliced and counted and the 14C/3H ratio was determined for each slice. A number of differences in 14C/3H ratios were observed between the NHPs isolated from MSH-treated and control cells which reflect changes in the synthesis and/or transport of NHPs in MSH-treated cells.


Neisseria meningitidis in the anal canal of homosexual men.

Cultures were obtained from the oropharynx, urethra, and anal canal of 157 homosexual men. Neisseria gonorrhoeae was identified in 30 men (19.1%), Neisseria meningitidis in 32 men (20.4%), and Neisseria lactamicus and Branhamella catarrhalis in one man each. N. gonorrhoeae was isolated from the anal canal of three men (1.9%), and N. meninititidis was identified in the anal canal of seven men (4.5%). These findings suggest that confirmatory tests are indicated for homosexual males with rectal isolates presumptively identified as N. gonorrhoeae.


Separation and characterization of plasma lipoproteins of rhesus monkeys (Macaca mulatta).

A group of 14 adult male rhesus monkeys was maintained on a low cholesterol-high fat diet. Periodically, animals were fasted and blood samples were taken for characterization of the plasma lipoproteins. Complete separation of individual plasma lipoprotein classes was not achieved by traditional sequential ultracentrifugation techniques. Rather, initial separation of lipoprotein classes according to size was effected and density centrifugation was used subsequently for further separation. At least six lipoprotein fractions were identified, each of which was unique as defined by the properties of size, density (d), and electrophoretic mobility. These lipoprotein fractions were characterized by determination of chemical compositions and apoprotein patterns. The lipoproteins present in highest concentration in these monkeys were designated as region IV lipoproteins. This fraction had alpha-migration on agarose electrophoresis, 1.063 < d < 1.225, and the size, composition, and apoprotein pattern characteristic of HDL. No fewer than three fractions were identified with densities that overlapped the 1.019 < d < 1.063 range. Of these, the fraction designated as region III lipoproteins was present in highest concentration, had beta-migration by agarose electrophoresis, a predominant B apoprotein, and a chemical composition and size characteristic of LDL. Two larger subfractions, identified as region II lipoproteins, were separated from each other at a density of 1.050 g/ml. Agarose electrophoresis showed that the fraction with d < 1.050 had a migration intermediate between beta and pre-beta. The chemical composition and apoprotein pattern were consistent with the possibility that these lipoproteins were remnants of VLDL catabolism. The fraction with d > 1.050, had pre-beta mobility and a size and composition similar to the Lp(a) lipoprotein in plasma of human beings. At least two VLDL subfractions, identified as region I and IIa lipoproteins, were found although both were present in very low concentrations. Region I lipoproteins were larger and contained relatively more cholesteryl ester and more of the apoproteins that migrated with the mobility of apo-B and arg-rich apoprotein in SDS-polyacrylamide gel electrophoresis. Some of the region I lipoproteins were beta-migrating by agarose electrophoresis. These results suggested the possibility that a beta-migrating VLDL was present in these normal animals.


Effects of luteinizing hormone releasing hormone on the ultrastructure of gonadotrophs in the foetus of the rhesus monkey near term.

Eighty micrograms of synthetic luteinizing hormone releasing hormone (LH-RH) were infused systemically into male and female foetuses of rhesus monkeys near term. Control animals were given infusions of saline. Morphologically, the control gonadotrophs varied from cells filled with secretory granules to highly stimulated cells with numerous cytoplasmic vesicles. In the LH-RH-treated animals, however, many cells showed depletion of secretory granules, dilatation of the endoplasmic reticulum and condensed nuclear chromatin. It is concluded, therefore, that foetal gonadotrophs can respond to administration of synthetic LH-RH.


Inhibition of thyrotrophin-releasing hormone responsiveness by physiological concentrations of thyroid hormones in the cultured rat pituitary gland.

Diced quarter anterior pituitaries from mature females Wistar rats were cultured in synthetic medium with or without added serum. Using each culture as its own control, the thyrotrophin-releasing hormone (TRH) dose-thyrotrophin (TSH) response characteristics of both media were similar; significant TSH secretion being stimulated at TRH doses around 1-5 X 10(-9) mol/l. During days 1-3 of culture, basal TSH secretion fell significantly but TRH responsiveness was unchanged. Neither tri-iodothyronine (T3) nor thyroxine (T4) influenced basal TSH secretion. In both culture media inhibition of TRH responsiveness was demonstrated with concentrations of T3 and T4 within the ranges 1-5 X 10(-12) to 1-5 X 10(-9) mol/l for T3 and 6-5 X 10(-10) to 6-5 X 10(-7) mol/l for T4. Equivalent inhibition was accompanied by similar T3 concentrations whether T3 or T4 supplements were used, suggesting that T4 itself has no feedback action. The similar concentrations of T3 required to inhibit TRH responsiveness in media either with or without serum suggest that the pituitary is responsive not only to free but also to total thyroid hormone concentrations, since serum-free medium contains no thyroid hormone-binding protein.


Effect of hypothalamic lesions on water metabolism of the toad Bufo marinus.

The rate of cutaneous water uptake after dehydration was significantly depressed in functionally neurohypophysectomized toads (Bufo marinus), which consequently regained weight much more slowly than intact toads when returned to water. Toads bearing hypothalamic lesions were able to develop an antidiuresis when removed from water to a saturated atmosphere, but the antidiuresis was solely glmerular in origin and was established more slowly than in intact animals. The fractional reabsorption of filtrate increased significantly and the relative free water clearance decreased significantly in intact toads after removal from water. These changes in tubular function, which were not seen in lesioned toads, were responsible for the development of a more rapid and effective antidiuresis in intact animals. Injections of iso-osmotic saline, oxytocin (250 mu./100 g) and vasopressin (50 mu./100 g) had no significant effect on rates of cutaneous water uptake in both intact and lesioned toads. Injections of hyperosmotic saline, however, significantly increased rates of water uptake in both groups of toads, but to a much greater extent in the intact animals. Fluid retention arising from a marked antidiuresis occurred after the injection of vasopressin and hyperosmotic saline, and there was some evidence of an antidiuretic effect of oxytocin with the doses used here. These results and their bearing on the question of the functional significance of the neurohypophysis in anuran amphibians are discussed.


Fixed-interval responding under second-order schedules of food presentation or cocaine injection.

Squirrel monkeys operated a key under second-order schedules in which every tenth completion of a 5-minute fixed interval resulted in either presentation of food or intravenous injection of cocaine. When a 2-second light was presented at the completion of the component fixed-interval schedules, positively accelerated responding developed and was maintained in each component. Over a tenfold range of doses of cocaine(30 to 300 microgram/kg/injection) and amounts of food (0.75 to 7.5 g/presentation); the second-order schedule of cocaine injection maintained higher average rates of responding than the second-order schedule of food presentation. Substituting saline for cocaine or eliminating food presentation decreased average rates of responding. When no stimulus change occurred at the completion of the first nine component fixed-interval schedules, but the 2-second light and food presentation or cocaine injection still occurred after the tenth component, only low and relatively constant rates of responding were maintained in each component. Patterns of responding characteristic of 5-minute fixed-interval schedules were maintained by the 2-second light paired with either cocaine injection or food presentation, though the maximum frequency of cocaine injection or food presentation was less than once per 50 minutes.


Orientation and lever responding in auditory discriminations in squirrel monkeys.

Head orientation during auditory discriminations was studies in squirrel monkeys using a two-lever trial-by-trial procedure. Animals were studied using auditory discriminations based on the position of the sound and on the spectral content differences between a pure tone and a noise. After the percentage of correct responses reached asymptote, head orientation was measured using videotape recordings. Orientation occurred on virtually every trial and was under the control of the position of the sound under all conditions. Lever responding was controlled by the same parameters of the sound under some conditions, and by different parameters in others. Orientation and lever responding were correlated (a level response could be predicted from the direction of orientation) when both responses were under the control of the same parameters of the sound. The two responses were uncorrelated when they were controlled by different parameters of the sound. Orientation and lever responding were not functionally related.


Control of responding by location of auditory stimuli: adjacency of sound and response.

Four rhesus monkeys were trained to respond on one key when a one-second noise burst was presented through one speaker and to respond on a second key when the noise burst was presented through a second speaker. The acquisition of stimulus control was studied under three conditions, in each of which the relationship between the sound source and the response-key positions varied: an adjacent condition in which the noise burst was presented through the key and a response on this key was reinforced; a reversed-adjacent condition in which the noise burst was presented through one key and responding on the other key was reinforced: and a nonadiacent condition in which responding on the key nearer the sound was reinforced. Under adjacent conditions, stimulus control developed within one or two sessions. Under reversed and nonadjacent conditions, 10 sessions were required for the development of control. The asymptote of correct responding was the same under each condition in all animals.


Antibody response to the streptococcal group A-variant polysaccharide in BASILEA rabbits lacking kappa-polypeptide chains.

Rabbits from a variant strain called BASILEA, in which homozygotes express only lambda-type chains and heterozygotes have normal kappa/lambda ratios, were hyperimmunized with a streptococcal group A variant vaccine. Homozygotes (bas/bas) produced antibodies with lambda-chains, heterozygotes, however, produced predominantly antibodies with kappa-chains. The incidence of restricted high responders in the BASILEA strain was high; it was probably introduced by the original mutant rather than by the loss of kappa-chains (founder effect). The degree of heterogeneity of homozygotes is similar to the heterogeneity of heterozygotes, and to that of rabbits expressing kappa-chains. This suggests that in the rabbit, the repertoire of lambda-chain genes is of similar size to that of kappa-chain genes.


Analysis of H-2 and Ia molecules by two-dimensional gel electrophoresis.

Mouse lymphocyte H-2 and Ia glycoproteins have been analyzed with a two-dimensional (2-D) acrylamide gel electrophoresis technique, in which proteins are separated first according to their charge in isoelectrofocusing gels and then according to their size in sodium dodecyl sulfate gels. Individual polypeptide chains from radiolabeled cells are resolved as discrete spots on autoradiograms of the gels, forming patterns which are characteristic of the proteins in the sample. 2-D gels of H-2K, H-2D, and Ia glycoproteins immunoprecipitated from 35S-methionine-labeled cells reveal that these proteins exist in the cells as complex arrays of molecules heterogeneous in both size and charge. Lactoperoxidase-catalyzed radioiodination of lymphocyte surfaces labels only subsets of the total H-2 and Ia molecules with 125I, indicating that some of the molecules may represent cytoplasmic precursors of the cell surface proteins. This theory is supported by the kinetics of labeling of various spots in 35S-methionine pulse-chase experiments. The 2-D gel patterns obtained for both H-2 and Ia antigens have also been shown to be haplotype-specific and independent of the genetic background.


Genetic control of cell-mediated responsiveness to an AKR tumor-associated antigen: mapping of the locus involved to the I region of the H-2 complex.

The role of H-2-linked genes in controlling resistance to murine leukemia viruses has been studied by measuring the cell-mediated immune response of F1 hybrid mice (between AKR and various C3H and C57BL/10 derived, H-2 congenic strains) to an AKR tumor cell line, BW5147. The studies have shown that the ability to generate a primary or secondary cell-mediated response to an AKR tumor cell antigenic determinant is under H-2 linked control. The locus determining CML responsiveness maps in the I-J subregion. Nonresponsiveness is associated with the H-2q/k and H-2b/k hybrid genotypes, whereas responsiveness is associated with the H-2k/k homozygous genotype. Nonresponsiveness may result from (a) dominant suppression; (b) recessive responsiveness; or (c) an alternate mechanism not yet understood. This type of control may be one of several H-2-associated mechanisms of defense against virus-induced neoplasms.


The genetic control of the immune response to staphylococcal nuclease VI. Recombination between genes determining the A/J anti-nuclease idiotypes and the heavy chain allotype locus.

Rat antisera detecting binding site-specific idiotypic determinants on anti-nuclease antibodies from A/J mice have been used to define the A/J anti-nuclease idiotype and to investigate its genetic linkage as a variable region marker. Analysis of the segregation of the A/J idiotype in progeny of the backcross (B10.A X A/J) X B10.A showed linkage of the idiotype to the Ig-1e heavy chain allotype locus. There was, however, a very high apparent frequency of recombination, with 7 of 101 backcross animals having a recombinant phenotype. All of these putative recombinants were accounted for by Ig-1b/Ig-1b homozygotes which bore the A/J idiotype, and none by Ig-1b/Ig-1e heterozygotes lacking the idiotype. On progeny testing of these animals in another backcross to B10.A the recombinant trait bred true. If this idiotype is indeed a marker for variable region structural genes, then the germ line gene pool must be very large or there must be special genetic mechanism to account for the increased recombinational frequency observed.


Suppression of human T-cell mitogenesis by prostaglandin. Existence of a prostaglandin-producing suppressor cell.

Small amounts of PGE inhibit mitogen-induced [3H]thymidine incorporation in human peripheral lymphocytes. The 50% inhibitory concentration is approximately 10(-7) M, and this is reduced to approximately 10(-8) M when endogenous PGE production is blocked. PGE inhibits PHA- and Con A-stimulated cultures much better than PWM cultures, suggesting a differential effect of PGE on T-cell vs. B-cell function. In vitro blockade of PG synthesis results in approximately 50% increase in [3H]thymidine incorporation in PHA cultures. PGE is produced endogenously in PHA cultures by glass adherent suppressor cells.


The role of H-2-linked genes in helper T-cell function. I. In vitro expression in B cells of immune response genes controlling helper T-cell activity.

The ability of murine helper T cells primed to the antigen, sheep erythrocytes (SRBC) to cross-react with burro erythrocytes (BRBC) in the in vitro anti-trinitrophenol (TNP) response to TNP-RBC was shown to be under genetic control. Although non-H-2 genes were shown to influence the absolute level of helper activity assayed after SRBC priming, the extent of cross-reaction of SRBC-primed helpers with BRBC was shown to be controlled by an H-2-1inked Ir gene(s). H-2 haplotypes were identified which determined high, intermediate, or low response to the cross- reacting determinants and the gene(s) controlling the cross-reaction tentatively mapped to the K through I-E end of the H-2 complex. Helpers primed in F(1) mice of high x intermediate or high x low responder parents were tested for cross-reaction using B cells and macrophages (Mphi) of parental haplotypes. In each case the extent of cross-reaction was predicted by the H-2 haplotype of the B cells and Mphi, establishing the expression of the Ir gene(s) in B cells and/or Mphi a t least, but not ruling out its expression in T cells as well. The low cross-reaction seen when T cells from F(1) mice of high x low responder parents were tested on low responder B cells and Mphi was not increased by the presence of high responder Mphi, indicating the Ir gene(s) is expressed in the B cell a t least although it may be expressed in Mphi as well. These and our previously reported experiments are consistent with the hypothesis that helper T cells recognize antigen bound to the surface of B cells and Mphi in association with the product(s) of Ir gene(s) expressed on the B cell and Mphi.


Allotype-specific analysis of anti-(Tyr,Glu)-Ala-Lys antibodies produced by Ir-1A high and low responder chimeric mice.

Katz et al. (1) have demonstrated a restriction in lymphoid cell interaction when the antigen used is under immune response (Ir) gene control. T cells from (low responder x high responder) F(1) mice primed to the terpolymer L-glutamic acid, L-lysine, L-tyrosine (GLT) can collaborate with 2,4-dinitrophenyl (DNP)-primed B cells from the Ir-GLT high responder but not low responder strain in response to DNP-GLT (1). In contrast are the studies of Bechtol et al. and Bechtol and McDevitt (2,3), who examined the antibody responses of tetraparental mice immunized with the synthetic polypeptide poly-L(Tyr,Glu)-poly D,L-Ala- poly-L-Lys ((T,G)-A-L), an antigen under Ir-1A genetic control. Several tetraparental mice produced anti(T-,G)-A-L antibody of low responder strain immunoglobulin (Ig) allotype (2,3). These results indicated that he Ir-1A gene was not expressed in B cells and implied that interactions among genetically dissimilar cell populations could occur when tolerance existed to H-2 antigenic differences. Recent studies with bone marrow cell chimeric mice have shown that chimeric T cells can interact with H-2 histoincompatible B cells in response to antigens not under Ir gene control (4-6). To clarify whether lymphoid cell chimerism, with presumed tolerance to H-2 incompatibility, would permit effective cell interactions in response to antigens under Ir gene control, bone marrow cell chimeric mice were prepared by using strains differing both for Ig allotype and for high versus low responsiveness to (T,G)-A-L. An antigen-specific and allotype- specific antibody assay was used to discriminate the responses produced by high and low responder strain B cells in these chimeras. The results suggest that lymphoid cell chimerism per se is not sufficient to obviate Ir gene-mediated restriction in cell interaction.


Secondary antibody responses in vitro to L-glutamic acid60-L-alanine30-L-tyrosine10 (GAT) by (responder X nonresponder)F1 spleen cells stimulated by parental GAT-macrophages.

The development of IgG L-glutamic Acid60-L-alanine30-L-tyrosine10 (GAT)-specific plaque-forming cell responses in vitro by virgin and immune (responder X nonresponder)F1 spleen cells after stimulation with responder and nonresponder parental GAT-macrophages (Mphi) was investigated. Virgin F1 spleen cells developed comparable primary responses to both parental GAT-Mphi. By contrast, F1 spleen cells from mice immunized with GAT or responder parental GAT-Mphi developed secondary responses after stimulation with only responder parental GAT-Mphi. Spleen cells from F1 mice immunized with nonresponder parental GAT-Mphi developed secondary responses to these GAT-Mphi, but failed to respond to responder parental GAT-Mphi. These results are discussed in the context of genetic restrictions regulating Mphi-T-cell interactions in secondary antibody responses and the possible expression of Ir-gene function in Mphi.


[Serum cholinesterase as a model glycoprotein (author's transl)].

Human serum cholinesterase (EC 3.1.1.8) is a carbohydrate-rich glycoprotein, which reacts with 18 different lectins from plants and invertebrates by a specific precipitin reaction; most of the lectins combine with alkali-stable bound carbohydrate chains. One third of these lectin receptors appear after neuraminidase-treatment, two thirds can be demonstrated before and after removal of neuraminic acid. The specific lectin receptors of the alkali-labile carbohydrate chains are characterized and analyzed by chemical and serological methods.


Cross reactivity of rabbit antibodies against purified animal enzymes. Comparison of enzymes of human and animal origin, II.

Enzyme preparations used for quality control of enzyme activity determinations in clinical chemistry should be very similar to human enzymes. Antibodies against e.g. porcine enzymes show cross reactivity with the corresponding human enzymes, indicating partial identity of the enzyme proteins. As the enzyme-antibody precipitates retain catalytic activity the similarity between the enzyme proteins is not limited to the catalytic sites.


Low-dose intravenous insulin: treatment of diabetic ketoacidosis in children (suitability for use in community hospitals).

A regimen is described to simplify current methods of ketoacidosis therapy by using only standard intravenous equipment and without requiring albumin administration. After an initial intravenous insulin bolus of 2 units, a dose of up to 3 units per hour was sufficient to bring patients out of ketoacidosis. No hypoglycemia, significant hypokalemia, or rapid fall in serum osmolality was detected. Patients showed steady increases in endogenous bicarbonate and were out of metabolic acidosis in 8.4 hours. This modified regimen appears to be a safe and easy method of treating diabetic ketoacidosis in children and is suited for use in community hospitals. Since the method is described for children over the age of three or those not in severe coma, consultation should be sought for any infant and for any child in severe coma or with a significant complication, such as severe infection.


Segregation during cleavage of a factor determining endodermal alkaline phosphatase development in ascidian embryos.

Localized alkaline phosphatase activity (EC 3.1.3.1) develops progressively in endodermal tissues of the presumptive digestive system in Ciona intestinalis embryos. It was first detected histochemically at late gastrulation, and a puromycin sensitivity period coincident with this time suggests that new alkaline phosphatase is synthesized. Embryos in which cell division was blocked with cytochalasin B at early cleavage stages up to the 64-cell stage, eventually differentiated strong alkaline phosphatase activity in certain cells at each cleavage-arrested stage. The maximum cell numbers and their positions were identical to those of the previously known endodermal cell lineage. Actinomycin D did not prevent development of endodermal alkaline phosphatase when administered from fertilization onwards, nor did other inhibitors of RNA synthesis (chromomycin A3, cordycepin, and daunomycin). There is probably a preformed maternal mRNA for endodermal alkaline phosphatase present in the unfertilizec Ciona egg. Either this RNA itself, or some related translation factor, is localized in the egg cytoplasm and segregated during early cleavages into the endodermal cell lineage of the embryo.


Inactivation of bacillus spores in dry systems at low and high temperatures.

A plot of the thermal resistance of Bacillus subtilis var. niger spores (log D value) against temperature was linear between 37 and 190 degrees C (z = 23 degrees C), provided that the relative humidity of the spore environment was kept below a certain critical level. The corresponding plot for Bacillus stearothermophilus spores was linear in the range 150 to 180 degrees C (z = 29 degrees C) but departed from linearity at lower temperatures (decreasing z value). However, the z value of 29 degrees C was decreased to 23 degrees C if spores were dried before heat treatment. The straight line corresponding to this new z value was consistent with the inactivation rate at a lower temperature (60 degrees C). The data indicate that bacterial spores which are treated in dry heat at an environmental relative humidity near zero are inactivated mainly by a drying process. By extrapolation of the thermal resistance plot obtained under these conditions for B. subtilis var. niger spores, the D value at 0 degrees C would be about 4 years.


The cultivation of the rumen ciliate Entodinium bursa in the presence of Entodinium caudatum.

The rumen ciliate protozoon Entodinium bursa has been grown in vitro in the presence of bacteria and Entodinium caudatum for over a year at population densities of 100 to 200 ml-1. The medium contained potassium phosphate, prepared fresh rumen fluid, cysteine, wholemeal flour (or rice starch), dried grass and a culture of the spineless form of Entodinium caudatum. Entodinium bursa has an obligate requirement for this protozoon and died within 48 h in its absence. During growth from a 2% inoculum, the mean generation time of E. bursa was 6 h. Entodinium bursa engulfed 1-5 to 2-5 E. caudatum organisms h-1, and when E. caudatum was in excess it developed caudal spines for the first time in 17 years; these spined forms were engulfed much less readily than the spineless organisms.


Morphological stages of Bacillus subtilis sporulation and resistance to fusidic acid.

During spore development of Bacillus subtilis both protein synthesis and sporulation become resistant to the antibiotic fusidic acid. This resistance develops at the time when asymmetric prespore septa are formed. Simultaneously ribosomes lose their ability to bind fusidic acid, as demonstrated by their affinity chromatography with the immobilized drug. Mutants resistant to fusidic acid during growth are oligosporogenous; their sporulation development is blocked before septum formation. These results indicate that normal ribosomes are needed for prespore septation sporulation; only after septation can protein synthesis be maintained, throughout the development period, by fusidate resistant ribosomes.


Host factor for coliphage Qbeta RNA replication as an aid in elucidating phylogenetic relationships: the genus Pseudomonas.

Host Factor (HF) is a heat-stable RNA-binding protein required along with Qbeta replicase for in vitro transcription of coliphage Qbeta RNA. We have found that HF activity and antigenicity are conserved among certain Gram-negative bacterial species. We examined selected species within the genus Pseudomonas for the presence of the HF polypeptide's antigenicity and Qbeta RNA replication function. While we were unable to detect either of these in Pseudomonas diminuta or Pseudomonas vesicularis, the other eleven species tested contained cross-reacting material to Escherichia coli HF. Furthermore, in six of these eleven species we were able to detect HF activity. The detection of HF structure and function allowed the examined species to be grouped into three categories which we have called 'sets'. The results correlate well with those of previous studies on ribosomal RNA homology (Palleroni et al., 1973).


Sequential expression of macromolecule biosynthesis and candicidin formation in Streptomyces griseus.

Streptomyces griseus did not produce the polyene macrolide antibiotic candicidin during the initial growth phase characterized by rapid RNA synthesis. the absence of candicidin production when RNA or protein synthesis was inhibited by rifampicin or chloramphenicol suggests a transcriptionally controlled late formation of the candicidin synthases. Phosphate levels in the medium control the rate of DNA, RNA and protein synthesis. Depletion of phosphate appears to trigger the onset of candicidin synthesis after a drastic reduction of the rate of RNA synthesis. Changes in the ATP pool during the fermentation suggest that ATP may be the intracellular effector controlling the onset of antibiotic synthesis.


Electrophysiological and anatomical estimation of the number of motor units in the monkey extensor digitorum brevis muscle.

The electrophysiological technique used to estimate the number of motor units in man (McComas et al., 1971b) was tested in six monkeys. The number of motor units was estimated electrophysiologically in the extensor digitorum brevis (EDB) after deafferentation by excision of the lumbo-sacral dorsal root ganglia. In five animals, the mean number of motor units obtained by the technique was in good agreement with the number of alpha motor fibres counted in the nerve to EDB. However, the results obtained in one animal with partial denervation of the EDB indicate that the technique might be unreliable, at least at certain stages, after a peripheral nerve lesion.


Effects of single dose supervoltage whole brain radiation in Macaca mulatta.

Three groups of four Macaca mulatta were exposed respectively to a single dose of 1000, 1500, and 2000 rads of 20 MeV whole brain radiation with one animal from each group and a control scheduled for sacrifice at 6, 12, 18, and 24 months. With 1000 rads there were no abnormalities. The characteristic lesions in the animals exposed to 1500 and 2000 rads were small foci of delayed radiation necrosis that in the acute phase were relatively large due to marked local accumulation of edema fluid and at later stages were decreased in volume and showed early mineralization. Correspondingly the monkeys frequently showed papilledema, evidently from brain swelling, as the initial clinical finding, and upon histological examination at later stages, brain atrophy and ventricular dilatation. After exposure to 1500 rads the necrotic process was primarily in the white matter of the cerebral hemisphere and progressed from a small number of lesions in this location at 6 months to confluent necrosis at 12 months. At 18 and 24 months, although there was no evidence of further necrosis, there was evidence of increasing gliosis and at 24 months the occurrence of three independent glioblastomas. With exposure to 2000 rads there was a profuse wide scatter of focal necrotic lesions with a predilection for the basis pontis and a clinical deficit inconsistent with survival past 6 months. Accumulation of minute mineral deposits and atherosclerotic plaques were also noted in these monkeys and appeared to be related to both dose and survival time.


Computer assisted tomography of focal cerebral radiation necrosis in the monkey.

The right occipital lobe in a series of pubescent monkeys was exposed to 3500 rads of orthovoltage radiation in a single dose. Sixteen to 38 weeks later the irradiated region broke down, rather abruptly. The visual evoked response, funduscopic photography, cerebral spinal fluid determinations for protein and lactic dehydrogenase, and computer assisted tomography (CAT) were used to anticipate and reflect the breakdown in neural tissue. CAT scanning demonstrated the two main effects of focal delayed radiation necrosis in this model (in a representative monkey): pronounced vasogenic edema from a break in the blood brain barrier, and contralateral hydrocephalus from brain distortion with obstruction of cerebral spinal fluid circulation. These findings were confirmed by postmortem examinations.


Clinical and endocrinological evaluation of 16 acromegalic patients treated by transsphenoidal surgery.

Sixteen patients with acromegaly treated with transsphenoidal pituitary surgery were evaluated with the measurement of serum human growth hormone (HGH) before and after intravenous stimulation with thyrotropin-releasing hormone (TRH). Fourteen of these patients showed a significant rise of serum HGH after TRH stimulation before surgery. After surgery, 12 patients with Grade 2 noninvasive adenomas had normal fasting serum HGH levels which did not stimulate with TRH. Two of these patients showed high serum HGH levels both at fasting and after TRH stimulation and required a second operation to remove residual adenoma within the sella before adequate lowering of HGH was achieved. Evidence of recurrent adenoma has not occurred clinically or biochemically in this group of 12 patients followed for an average of 24 months (2 to 60 months). The results were unsatisfactory in four of these 16 patients. One patient who has a postoperative HGH of 9 ng/ml which still stimulates with TRH has made clinical improvement, but must have residual adenoma in the sella or invasive adenoma in the dura and tumor capsule. Additional treatment with irradiation has been given. Failure to achieve satisfactory results in the other three patients was attributed to the presence of locally invasive adenoma; one in the sphenoid sinus, and the other two possibly as a consequence of previous operative procedures.


Chronic demeclocycline therapy in the syndrome of inappropriate ADH secretion due to brain tumor.

The treatment of the syndrome of chronic inappropriate antidiuretic hormone (ADH) secretion by fluid restriction is often attended by poor patient compliance. The following case report illustrates successful management of this condition by oral demeclocycline therapy in a patient who had hyponatremia in association with angioblastic meningioma of the sphenoid ridge.


Steady-state evoked potentials.

The advantages of steady-state EP recording include (1) speed in assessing sensory function in normal and sick infants (e.g., in amblyopia) and in sick adults (e.g., in multiple sclerosis); (2) monitoring certain activities of sensory pathways that do not intrude into conscious perception; (3) rapidly assessing sensory function when a large number of subjects must be tested (e.g., in refraction); (4) objective measurement at very high suprathreshold levels where psychophysical methods are difficult or ineffective; (5) rapidly assessing sensory function in normal subjects when EP variability and nonstationarity preculde lengthy experiments; and (6) proving a speedy objective equivalent to behavioral test in animals.


Use and complications of high-dose disodium etidronate therapy in fibrodysplasia ossificans progressiva.

A boy with fibrodysplasia ossificans progressiva received nearly twice the usual therapeutic dose of disodium etidronate for 13 months in an attempt to prevent reossification following a second operation to correct severe torticollis. The operation was successful, but during therapy he developed weakness and distinctive bone lesions characterized by general osteopenia, widened physes, and unique radiolucent bands in the metaphyses. The osseous abnormalities were distinct from those of rickets and healed after withdrawal of the drug.


Chlorthalidone analysis using carbonic anhydrase inhibition.

Chlorthalidone was analyzed in the concentration range of 0.1-3.0 microgram/ml with a precision of +/- 0.05 microgram/ml. Chlorthalidone inhibition of the enzymatic hydrolysis rate of p-nitrophenyl acetate by bovine erythrocyte carbonic anhydrase was used as a basis for the determination. The amount of p-nitrophenol formed was measured by monitoring the absorbance at 400 nm, and its formation rate was proportional to the chlorthalidone concentration. The mixing of the enzyme, substrate, and sample, the incubation of the reaction mixture, and the recording of the absorbance were automated. A survey of urine samples from 26 normal human subjects did not reveal any endogenous substances that interfered with the assay. Analyses of urine samples from six subjects after oral administration of 100 mg of chlorthalidone indicated rapid absorption and a biphasic elimination. The alpha-phase half-life was 1.5 hr, and the beta-phase half-life was 35 hr.


Absence of mutagenicity of coralyne and related antileukemic agents: structural comparison with the potent carcinogen 7,12-dimethylbenz[a]anthracene.

The structural similarity between antileukemic alkaloid coralyne and the carcinogenic and antineoplastic hydrocarbon 7, 12-dimethylbenz[a]anthracene, as well as the similarity between the antileukemic alkaloid nitidine and the carcinogenic hydrocarbon 5-methylchrysene, prompted a mutagenicity evaluation of coralyne sulfoacetate, nitidine chloride, the 8-ethyl homolog of coralyne, nitidine methosulfate, and the tetramethoxy analog of nitidine by the Ames method against the histidine-auxotroph strains of Salmonella typhimurium TA-1537, TA-1538, TA-98, and TA-100; 7,12-dimethylbenz[a]anthracene was used as a reference standard. The mutagenicity of these antileukemic compounds was either completely eliminated or drastically reduced, but the mutagenic response was generally high for 7,12-dimethylbenz[a]anthracene. The results suggest that the presence of a quaternary nitrogen atom and alkoxy groups could be important in alleviating the mutagenicity of the parent mutagenic and carcinogenic hydrocarbons.


The pharmacology of SC-27166: a novel antidiarrheal agent.

SC-27166 is the result of continuing efforts to discover selective and orally active antidiarrheal agents. SC-27166, which is chemically unrelated to opiates or neuroleptics, possesses potent constipating and antidiarrheal activity in several animal models. Tolerance to the constipating actions of SC-27166 did not develop in mice. On the other hand, gut tolerance rapidly developed to morphine sulfate and loperamide. The basic mechanism of the antidiarrheal action of SC-27166 is a consequence of increased intestinal circular muscle contractile activity. Supportive pharmacological studies indicated that SC-27166 has equivocal analgesia in mice which is manifested at near toxic dose levels. SC-27166 was also evaluated for potential dependence liability in morphine abstinence-induced jumping in mice. The abstinence-induced jumping was suppressed to a far lesser extent by SC-27166 than by either loperamide or diphenoxylate at equal doses. SC-27166 was also devoid of anticbholinergic activity. When compared with the reference standards morphine and diphenoxylate, these pharmacological studies indicated that SC-27166 has a high degree of separation of undesirable central nervous system actions from its antidiarrheal properties and may have important therapeutic potential.