Intracranial fibrosarcoma arising 5 years after chemotherapy alone for glioblastoma multiforme in a child

We present a child diagnosed with glioblastoma multiforme during infancy and successfully treated with the 'eight-in-one' chemotherapy regimen, who developed an intracranial fibrosarcoma 5 years later. After resection of the fibrosarcoma, she received cranial radiation therapy and high dose chemotherapy with bone marrow transplant. She remains alive and recurrence-free 7 years following the diagnosis of her second intracranial malignancy.

The degradation profile of extrachromosomal circular DNA during cisplatin-induced apoptosis is consistent with preferential cleavage at matrix attachment regions

Extrachromosomal circular DNA molecules are prevalent in cancer cells and harbor amplified genes, such as oncogenes and drug resistance genes, that can provide a selective growth advantage to cancer cells. These circular DNA structures include double minute chromosomes (dmin), which can be detected with light microscopy following Giemsa staining, and submicroscopic circular DNA structures referred to as episomes. In this study, we investigated the fate of dmin and episomes in multidrug-resistant human epidermoid KB-VI cells undergoing cisplatin-induced apoptosis-a mode of cell death initially characterized by the fragmentation of chromosomal DNA, while the nuclear membrane remains intact. The circular DNA structures carry amplified copies of the multidrug resistance gene (MDR1). During cisplatin-induced apoptotic cell death, episomes and dmin, as well as native chromosomes, were degraded into high molecular weight DNA fragments of approximately 50 kb in length. DNA fragments in this size range appear to result from the preferential cleavage of matrix-associated regions in chromatin with the subsequent release of 20-30 nm loop domains of chromatin from the nuclear scaffold. Scanning electron microscopy studies were performed and confirmed the presence of 30 nm filaments in a higher-order DNA packing of MDR1-containing dmin and episomes. These combined data provide strong evidence that the higher-order DNA packing of episomes, as well as dmin, is similar to that of native chromosomes and underscore the potential for extrachromosomal DNA amplicons to study the structural and functional organization of chromatin. We discuss the implications of extra-chromosomal DNA matrix associated regions competing with native chromosomal DNA for binding to the nuclear matrix in tumor cells.

Fractionated ionizing radiation accelerates loss of amplified MDR1 genes harbored by extrachromosomal DNA in tumor cells

In tumor specimens such as those from neuroblastoma, ovarian, and lung carcinoma patients, the prevalence of extrachromosomal circular DNA molecules harboring amplified genes has been well established. In some cases, the amplified genes have been identified as oncogenes, and their increased expression appears to contribute to the maintenance and progression of the malignancy. The aim of this study was to investigate the effect of fractionated radiation treatment, given in daily doses similar to those administered clinically, on the stability of extrachromosomal circular DNA molecules in cancer cells. Our studies were conducted with multidrug-resistant KB cells, which harbor extrachromosomal copies of the multidrug resistance gene (MDR1) almost exclusively on circular DNA molecules of approximately 750 and 1500 kb pairs. This size range is representative of extrachromosomal circular DNA molecules that have been shown to harbor amplified oncogenes in vivo. Exponentially growing MDR KB cells were exposed to 1400 and 2800 cGy ionizing radiation administered in 7 and 14 fractions, respectively, at 200 cGy per fraction/day. A statistically significant decrease in MDR1 extrachromosomal gene copy number was reproducibly detected in the irradiated cells compared with unirradiated cells passaged for the duration of the experiment in the absence of radiation treatment. This decrease was accompanied by a reduction in multidrug resistance and in P-glycoprotein levels, as determined by clonogenic dose-response assays and Western analyses, respectively. P-glycoprotein is a multidrug transporter encoded by the MDR1 gene. Fluorescence in situ hybridization studies further determined that extrachromosomal circular DNA loss correlated to the entrapment of these DNA molecules in radiation-induced micronuclei. These results indicate that radiation-induced loss of extrachromosomally amplified genes from tumor cells via their entrapment in micronuclei contributes to the improved therapeutic response observed for some cancers.

Presentation of nursing diagnosis content in fundamentals of nursing textbooks

The technique and rationale for the use of nursing diagnosis generally are introduced early in the undergraduate curriculum. The three purposes of this descriptive study were to describe the general characteristics and presentation of content on nursing diagnosis in fundamentals of nursing textbooks; describe how the content from the theoretical chapter(s) in nursing diagnosis is carried through in the clinical chapters; and describe how content on diagnostic errors is presented. Although most of the textbooks presented content on nursing diagnosis in a similar fashion, the clinical chapters of the books did not follow the same pattern. Content on diagnostic errors was inconsistent. Educators may find this an effective methodology for reviewing textbooks.

Ga-67 used to localize the tumor bed for radiation therapy after lumpectomy

The authors present a new method to locate the tumor bed after lumpectomy. The method relies on accumulation of Ga-67 at the surgical site. This technique was useful in identifying the tumor bed in six candidates for breast conserving surgery and radiation therapy. This method may be applicable in other soft tissue malignancies that require postoperative radiation.

Double minute chromosomes carrying the human multidrug resistance 1 and 2 genes are generated from the dimerization of submicroscopic circular DNAs in colchicine-selected KB carcinoma cells

This study characterizes amplified structures carrying the human multidrug resistance (MDR) genes in colchicine-selected multidrug resistant KB cell lines and strongly supports a model of gene amplification in which small circular extrachromosomal DNA elements generated from contiguous chromosomal DNA regions multimerize to form cytologically detectable double minute chromosomes (DMs). The human MDR1 gene encodes the 170-kDa P-glycoprotein, which is a plasma membrane pump for many structurally unrelated chemotherapeutic drugs. MDR1 and its homolog, MDR2, undergo amplification when KB cells are subjected to stepwise selection in increasing concentrations of colchicine. The structure of the amplification unit at each step of drug selection was characterized using both high-voltage gel electrophoresis and pulsed-field gel electrophoresis (PFGE) techniques. An 890-kb submicroscopic extrachromosomal circular DNA element carrying the MDR1 and MDR2 genes was detected in cell line KB-ChR-8-5-11, the earliest step in drug selection in which conventional Southern/hybridization analyses detected MDR gene amplification. When KB-ChR-8-5-11 was subjected to stepwise increases in colchicine, this circular DNA element dimerized as detected by PFGE with and without digestion with Not 1, which linearizes the 890-kb amplicon. This dimerization process, which also occurred at the next step of colchicine selection, resulted in the formation of cytologically detectable DMs revealed by analysis of Giemsa-stained metaphase spreads.

A phase II study of mitoguazone and vinblastine in advanced transitional cell carcinoma of the urinary tract

This is a comparative study to evaluate response rate to mitoguazone (MGBG) and vinblastine (VLB) in 52 evaluable patients with advanced transitional cell carcinoma of the urinary tract. Of 38 patients with measurable disease, two of 18 (11%) on MGBG had partial remission (95% confidence interval: 0.01, 0.35), whereas four of 20 (20%) responded on the VLB arm (95% confidence level: 0.06-0.44). Both responses on the MGBG arm were seen in patients given prior chemotherapy. Side effects of both drugs were significant, with 46% of patients given VLB developing severe or life-threatening hematologic toxicity. Data indicate that both drugs, as single agents, are probably inferior to cisplatin for control of advanced transitional cell carcinoma of the urinary tract.

Spectrophotometric evaluation of carboxyhemoglobin in blood of mice after exposure to marijuana or tobacco smoke in a modified Walton horizontal smoke exposure machine

Carboxyhemoglobin (COHb) values were determined in mice exposed to varying amounts of marijuana and tobacco cigarette smoke utilizing a spectrophotometric technique. Mice were exposed to smoke inhalation in a modified Walton horizontal smoke exposure machine, whereby rodents can be exposed to multiples of 1-min smoke exposure cycles. Smoke exposure was intermittent; during the first 30 sec of each 1-min cycle, the subjects were exposed to smoke diluted either 1:10 or 1:5 with air. During the second half of the cycle the animals were given fresh air. There was a positive linear relationship between COHb values obtained and the number of puffs of marijuana smoke administered via either 2, 4, 6, or 8 "puffs" of marijuana smoke. COHb levels in plasma did not increase in animals given multiple 8-puff episodes of smoke daily as long as a 60-min period was interposed between smoking episodes. COHb values in mice exposed to tobacco smoke were significantly higher than those in mice receiving equal numbers of exposures to marijuana smoke. Mean COHb values of mice receiving 8 consecutive puffs of marijuana smoke were 18.6 and 22.0% saturation, but CO was rapidly cleared from the blood. This rapid clearance suggests that the binding affinity of CO for mouse hemoglobin may be be weaker than that of human hemoglobin. Mice similarly exposed to 6 or 8 puffs of tobacco smoke had mean COHb values of 24.6 and 28.5% saturation, respectively. No acute lethal effects were observed in mice receiving multiple daily episodes of 8 puffs per episode of marijuana smoke, whereas mice exposed to a single 8-puff episode of tobacco smoke suffered about 50% acute lethal effects.

Aggregation of platelets by Fusobacterium necrophorum

Broth cultures and washed cells of 13 of 24 bovine isolates of Fusobacterium necrophorum aggregated human platelets in platelet-rich plasma. The cell-free culture fluid was inactive. Bacteria stored at 4 degrees C in saline remained active for at least 3 months, but they did not release activity into the storage solution. Aggregation typically began within 1 min after the addition of 10(3) bacteria to 10(3) platelets was complete within 5.5 min. Assays for cytosolic lactic dehydrogenase revealed that platelet lysis did not occur. The release of [14C]serotonin from platelets preincubated with this amine accompanied aggregation, indicating that this was a typical aggregation-degranulation reaction. Platelet aggregation was inhibited by EDTA (88% at 2.0 mM), aspirin (75% inhibition at 1.0 mM), and quinacrine (80% inhibition at 0.25 mM). Thus the reaction was an ion-dependent, cyclooxygenase-sensitive event. Gel-filtered platelets were less sensitive to aggregation than were platelets in plasma, but this sensitivity was fully restored by the addition of plasma and partially restored with fibrinogen. Biotyping of the cultures revealed that none of the avirulent, B-type strains of F. necrophorum could aggregate platelets, whereas 13 of 16 virulent A type strains were positive. These results suggest that platelet aggregation by F. necrophorum is related to the virulence of this organism.

Genetic and physical analyses of Caulobacter crescentus trp genes

Caulobacter crescentus trp mutants were identified from a collection of auxotrophs. Precursor feeding experiments, accumulation studies, and complementation experiments resulted in the identification of six genes corresponding to trpA, trpB, trpC, trpD, trpE, and trpF. Genetic mapping experiments demonstrated that the trp genes were in two clusters, trpCDE and trpFBA, and a 5.4-kilobase restriction fragment from the C. crescentus chromosome was isolated that contained the trpFBA gene cluster. Complementation experiments with clones containing the 5.4-kilobase fragment indicated that trpF was expressed in Escherichia coli and that all three genes were expressed in Pseudomonas putida. This expression was lost in both organisms when the pBR322 tet gene promoter was inactivated, indicating that all three genes were transcribed in the same orientation from the tet promoter. Thus, the C. crescentus promoters do not seem to be expressed in E. coli or P. putida. Complementation of the C. crescentus trp mutants indicated that the tet promoter was not necessary for expression in C. crescentus and suggested that at least two native promoters were present for expression of the trpF, trpB, and trpA genes. Taken together, these results indicate that C. crescentus promoters may have structures that are significantly different from the promoters of other gram-negative species.

Platelet aggregation by Streptococcus pyogenes

Heat-killed group A Streptococcus pyogenes induced platelet aggregation in platelet-rich plasma. Aggregation was dependent upon the ratio of platelets to bacteria, with maximal aggregation occurring at 0.8 platelets per bacterium (final concentration, 300,000 per microliter). Inhibition of the reaction by 3 mM EDTA indicated it was a true aggregation and not merely adhesion and agglutination. Lactic acid dehydrogenase assays indicated lysis of platelets did not occur during a 6-min incubation period. Aggregation was inhibited in a dose-dependent manner by acetylsalicylic acid (100 microM to 10 mM) and quinacrine (15.6 to 250 microM), with no decrease in aggregation at the lowest concentration of inhibitor tested. S. pyogenes induced the release of [14C]serotonin, which was maximal (50%) at 2.4 min, when aggregation was nearly complete. Gel-filtered platelets were not aggregated unless fibrinogen (final concentration, 1.8 mg/ml) was included in the reaction mixture. Staphylococcus aureus, a group B streptococcus, and Escherichia coli were unable to induce aggregation in platelet-rich plasma under the conditions used for S. pyogenes.

Genetic mapping with Tn5-derived auxotrophs of Caulobacter crescentus

Chromosomal insertions of Tn5 in Caulobacter crescentus displayed complete stability upon transduction and proved useful in strain building on complex media. RP4-primes constructed in vitro containing C. crescentus genomic sequences in the HindIII site of the kanamycin resistance gene failed to show enhanced or directed chromosome mobilization abilities. One of these kanamycin-sensitive RP4 derivatives, pVS1, was used as a mobilization vector in conjugation experiments on complex media where chromosomal Tn5 transfer to the recipient was selected. pVS1-mediated transfer of Tn5-induced auxotrophic mutations occurred at frequencies of 10(-6) to 10(-8) per donor cell. During conjugation with Tn5-encoded kanamycin resistance as the selected marker, Tn5 remained in its donor-associated locus in 85 to 100% of the transconjugants. A collection of eight temperature-sensitive donor strains bearing Tn5 insertion mutations from various regions of the C. crescentus genetic map were used to provide a rapid means for the determination of the map location of a new mutation. Use of the techniques described in this paper allowed an expansion of the C. crescentus genetic map to include the relative locations of 32 genes.

Characterization of opsonins for Bacteroides fragilis in immune sera collected from experimentally infected mice

Serum collected from mice experimentally infected with Bacteroides fragilis 23745 (immune serum) was analyzed for its ability to opsonize the in vitro ingestion of this organism by mouse peritoneal macrophages. B. fragilis was shown to be phagocytized most efficiently in the presence of immune serum although normal mouse serum demonstrated reduced, but significant, opsonic activity. Phagocytosis was greater in the presence of serum collected from animals inoculated twice with the organism than in the presence of serum from once-inoculated animals. The increased opsonic activity of serum from twice-inoculated animals compared to singly inoculated animals was associated with increases in immunoglobulin G1(IgG1), IgG2a, and IgG2b but not IgM. Adsorption analysis of immune serum with homologous or heterologous bacterial antigens indicated that both antibody and complement act synergistically in opsonizing B. fragilis, although either alone may effectively opsonize this organism. Further evaluation of antibody-mediated opsonization revealed that prior treatment of heat-inactivated immune serum with the reducing agent 2-mercaptoethanol caused a slight, but significant, decrease in opsonic activity, thus indicating that IgM is a minor opsonizing antibody for B. fragilis. When ingestion of a B. fragilis stock strain (23745) was compared to a recent clinical isolate (C-1), it was observed that the stock strain was more easily phagocytized in the presence of normal mouse serum, thus suggesting a possible anti-opsonic-phagocytic property of the clinical strain. In addition, the clinical isolate was phagocytized to a significantly greater degree in an aerobic than an anaerobic environment. Subsequent analysis of in vitro killing of B. fragilis 23745 by peritoneal macrophages reflected the previous results in that optimal killing occurred in the presence of immune serum, although normal serum promoted phagocytic killing to an intermediate degree. Thus, these studies implicate both antibody and complement, either alone or in combination, in the opsonization of B. fragilis. Moreover, the virulence of clinical B. fragilis strains may relate to their refractoriness to opsonization and phagocytosis.

Construction of a genetic map for Caulobacter crescentus

RP4-mediated conjugation has been used to transfer large fragments of chromosomal material in Caulobacter crescentus. In this system, conjugation proceeds from multiple origins, and haploid recombinants are recovered at frequencies of 10(-6) and 10(-7) per donor cell. The data from five-factor crosses were subjected to computer-assisted crossover analyses as a rapid method to determine marker order. Using this information and data from additional two- and three-factor crosses mediated by RP4 or the generalized transducing bacteriophage phi Cr30, we constructed the first genetic map for C. crescentus.

Platelet aggregation and sphingomyelinase D activity of a purified toxin from the venom of Loxosceles reclusa

A facile and quantitative assay for measuring the activity of sphingomyelinase D in recluse spider venom has been developed using L-alpha-[palmitoyl-1-14C]lysophosphatidylcholine as substrate. This assay avoids the problem of substrate insolubility that occurs when sphingomyelin and other insoluble lipids are used as substrates. This assay has been employed in gel filtration and isoelectric focusing isolation techniques to purify sphingomyelinase D from spider venom. The purified sphingomyelinase exhibits four active enzyme forms in isoelectric focusing with pI values of 8.7, 8.4, 8.2, and 7.8. Each active form when examined in SDS-polyacrylamide gel electrophoresis gave an estimated molecular weight of 32 000. The four active enzyme forms were immunologically cross-reactive with each other as demonstrated with radioimmune assays using an antiserum developed to one of the active forms. Each active form hydrolysed sphingomyelin to release choline and produce N-acylsphingosine phosphate. One of the active enzyme forms was characterized further in dermonecrosis and platelet aggregation measurements. This purified sphingomyelinase D was identified as a poisonous toxin that can developed typical dermonecrotic spider lesions when injected into experimental animals at levels expected to be delivered in a normal bite. Furthermore, the purified toxin acts to aggregate human blood platelets. The toxin-induced platelet aggregation has been related to serotonin release as aggregation occurs, and it has been shown to be inhibited by EDTA over the range of 0.6 yo 3.0 mM EDTA. It is suggested that spider-induced dermonecrosis could result in part from platelet aggregation at and near the site of envenomation.

Alternate complement pathway activation by recluse spider venom

Venom from the poisonous brown recluse spider (Loxosceles reclusa) catalyses the lysis of dithiothreitol-treated human erythrocytes when incubated with serum complement but not in heat inactivated serum, a characteristic of complement system activation via the alternate pathway. This activity of the venom was shown to reside in a Sephadex G-75 fraction of the venom which also contains the dermonecrotoxin. Isoelectric focusing of this fraction identified the complement inactivating molecules(s) in the region near pH=6. Analysis of complement after interaction with venom indicated a loss of haemolytic C3. Immunoelectrophoretic development of venom-complement mixtures with anti C3 proactivator revealed the appearance of the C3 activator. These data indicate that recluse spider venom activates the alternate complement pathway.

Chemotaxis by lipids isolated from Bacteroides fragilis

Living, heat or formalin killed Bacteroides fragilis and a crude preparation of their cell walls were examined by the Boyden technique for chemotactic activity upon guinea pig peritoneal exudate cells. Their relative chemotactic activity ranged from 3.0 to 5.2 compared to an average value of 6.4 for the positive control, an endotoxic culture filtrate of Escherichia coli. A culture filtrate of B. fragilis and an index of 3.7. Miocrogram quantities of cytoplasmic preparations obtained by ammonium sulphate precipitation had chemotactic indices ranging from 2.8 to 6.4, the highest value being displayed by the precipitate formed between 50 and 75% saturation with ammonium sulphate. This fraction retained leucotactic activity after exposure to strong acid and heat. The leucotactic potency of these fractions did not correlate directly with their protein content. Further precipitation of the most active fraction with 80% ethanol revealed that there was little chemotactic activity attributable to polysaccharides. Gas liquid chromatography of a chloroform-methanol extract of the cells which had a chemotactic index of 6.1 revealed the presence of more than thirty fatty acids ranging in carbon length from C8 to C25. These results suggest a role of lipids as initiators of the leucotactic response associated with infections caused by B. fragilis.

Inactivation of complement by Loxosceles reclusa spider venom

Zymosan depletion of serum complement in guinea pigs rendered them highly resistant to lesion by Loxosceles reclusa spider venom. Guinea pigs deficient in C4 of the complement system are as sensitive to the venom as normal guinea pigs. The injection of 35 micrograms of whole recluse venom intradermally into guinea pigs lowered their complement level by 35.7%. Brown recluse spider venom in concentrations as slight as 0.02 micrograms protein/ml can totally inactivate one CH50 of guinea pig complement in vitro. Bee, scorpion, and other spider venoms had no influence on the hemolytic titer of complement. Fractionation of recluse spider venom by Sephadex G-200 filtration separated the complement-inactivating property of the venom into three major regions which could be distinguished on the basis of heat stability as well as size. None was neutralized by antivenom. Polyacrylamide gel electrophoresis of venom resolved the complement inactivators into five fractions. Complement inactivated by whole venom or the Sephadex fractions could be restored to hemolytic activity by supplements of fresh serum but not by heat-inactivated serum, pure C3, pure C5, or C3 and C5 in combination.

Antibodies detectable by counterimmunoelectrophoresis against Bacteroides antigens in serum of patients with inflammatory bowel disease

Heat-extracted antigens from seven species of Bacteroides were used in passive hemagglutination and counterimmunoelectrophoretic tests. Sera from 87 normal persons (group I) and 15 patients with ulcerative colitis (group II) were of low and equal reactivity in passive hemagglutination tests; all positive tests were eliminated by 2-mercaptoethanol reduction of the sera. When these same sera were tested by counterimmunoelectrophoresis with six of the Bacteroides antigens, no significant difference in the percentage of positive reactions was noted. However, using the chi-square test, the seventh antigen, prepared from Bacteroides vulgatus, successfully distinguished the two populations at the 0.025 level. Counterimmunoelectrophoretic tests with the B. vulgatus antigen also provided a means to separate the patients in group II with active disease from those in remission at a P value of 0.01. All the sera from 12 patients with defined Crohn's disease activity indexes reacted with the B. vulgatus antigen in counterimmunoelectrophoretic tests. Reduction and alkylation of patient sera with 2-mercaptoethanol and iodoacetamide removed detectable antibody in 78% of the samples, which suggested a dominant role of immunoglobulin M in the response to Bacteroides antigens.

Factors related to the oxygen tolerance of anaerobic bacteria

The effect of atmospheric oxygen on the viability of 13 strains of anaerobic bacteria, two strains of facultative bacteria, and one aerobic organism was examined. There were great variations in oxygen tolerance among the bacteria. All facultative bacteria survived more than 72 h of exposure to atmospheric oxygen. The survival time for anaerobes ranged from less than 45 min for Peptostreptococcus anaerobius to more than 72 h for two Clostridium perfringens strains. An effort was made to relate the degree of oxygen tolerance to the activities of superoxide dismutase, catalase, and peroxidases in cell-free extracts of the bacteria. All facultative bacteria and a number of anaerobic bacteria possessed superoxide dismutase. There was a correlation between superoxide dismutase activity and oxygen tolerance, but there were notable exceptions. Polyacrylamide gel electropherograms stained for superoxide dismutase indicated that many of the anaerobic bacteria contained at least two electrophoretically distinct enzymes with superoxide dismutase activity. All facultative bacteria contained peroxidase, whereas none of the anaerobic bacteria possessed measurable amounts of this enzyme. Catalase activity was variable among the bacteria and showed no relationship to oxygen tolerance. The ability of the bacteria to reduce oxygen was also examined and related to enzyme content and oxygen tolerance. In general, organisms that survived for relatively long periods of time in the presence of oxygen but demonstrated little superoxide dismutase activity reduced little oxygen. The effects of medium composition and conditions of growth were examined for their influence on the level of the three enzymes. Bacteria grown on the surface of an enriched blood agar medium generally had more enzyme activity than bacteria grown in a liquid medium. The data indicate that superoxide dismutase activity and oxygen reduction rates are important determinants related to the tolerance of anaerobic bacteria to oxygen.

Enzyme immunoassay for hepatitis B and its comparison to other methods

A solid-phase enzyme immunoassay for the qualitative detection of hepatitis B surface antigenemia is presented and the results compared to the counter-immunoelectrophoresis and radioimmunoassay methods for detection of the same antigen. The enzyme-antibody conjugate was prepared from horseradish peroxidase coupled with antibodies to three sub-types of hepatitis B virus. Polystyrene plastic tubes were used as the solid-phase support. The results of the enzyme immunoassay compare favorably with radioimmunoassay and exceed counterimmunoelectrophoresis in sensitivity.

Inhibition of leukocyte chemotaxis by homogenates of tumor tissues

Homogenates of human cancer tissues were assayed for chemotactic activity in modified Boyden chambers utilizing polycarbonate filters with an 8micron pore size. Peritoneal exudate cells (PEC) of guinea pigs were used as indicator cells in the assays and the chemotactic responses of both eosinophilic and neutrophilic leukocytes were recorded. The chemotactic responsiveness of leukocytes to the majority of homogenates was significantly less than that observed with the negative controls. It is suggested that the anti-chemotactic activity observed in vitro may operate in vivo to abrogate inflammatory responses and tumor rejection.

Molar pregnancy of hyperthyroidism

A report on a patient with clinical hyperthyroidism associated with hydatidiform mole is presented. Some biochemical characteristics of the thyroid stimulator isolated from the tumour are discussed.

Immunological studies of Brown recluse spider venom

Polyacrylamide gel electrophoresis of Loxosceles reclusa venom demonstrated that only one of seven or eight major (plus three or four minor) protein components caused necrosis in guinea pig skin. Sephadex gel filtration separated the venom into three major peaks, the second peak of which contained the dermonecrotic activity. Hyperimmunization of rabbits with increasing doses of venom from L. reclusa produced potent precipitating antisera, and the rabbits became resistant to lesion development. Ouchterlony-type immunodiffusion and immunoelectrophoretic studies revealed six to seven distinct precipitation lines, one of which stained intensely for esterase activity. Immunohistochemical techniques failed to detect any protease, lipase, catalase, acid phosphatase, alkaline phosphatase, or amylase activity in the venom. The spreading activity of recluse spider venom in guinea pig skin was inhibited as much as 71% by antivenom. Venom preincubated with antivenom was unable to incite lesions in guinea pig skin. Passive immunization of guinea pigs 18 h before an injection of venom conferred venom resistance upon the animals. Local injections of antivenom immediately after intradermal injections of venom markedly reduced the dermal lesion. Heparin reduced the local and systemic effects of venom when preincubated with whole venom or when administered systemically before an intradermal injection of venom. Treatment of whole venom with the chelating agent ethylenediaminetetraacetate did not inhibit its necrotic activity. Transfer studies from a 24-h lesion indicated that the necrotic activity was localized and remained active in tissue for at least 24 h but not for 5 days. No lesions developed when high concentrations of venom were intradermally injected into the skin of sacrificed guinea pigs, indicating that an interaction of body constituents and venom is essential for the development of a lesion.

Lipoprotein inhibitor of Newcastle disease virus from chicken lung

A lipoprotein inhibitor of Newcastle disease virus was obtained from chicken lung tissue by means of dilute alkaline extraction procedures. The inhibitor was further purified by ammonium sulfate fractionation, isoelectric precipitation, and density gradient centrifugation. The purified lipoprotein inhibited active Newcastle disease virus hemagglutination at a concentration of 2.0 mug/ml which represented a 30-fold purification over the original extract. Infection of chicken embryo fibroblasts by Newcastle disease virus was also inhibited by the purified lipoprotein, the degree of inhibition depending upon the inhibitor-to-virus ratio. Chemical analysis of the purified inhibitor provided a composition of 72% lipid, 26% protein, and 3% carbohydrate, although some compositional variation was observed from one preparation to another. The chloroform-soluble lipids were shown to contain 40 to 50% phospholipid and 10 to 20% cholesterol; of the fatty acids recovered from the saponified lipoprotein, 39% was palmitic, 22% oleic, and 17% stearic. Careful analyses of large quantities of the inhibitor revealed a small (0.84%) but significant content of sialic acid. Removal of sialic acid from the lipoprotein by means of digestion with neuraminidase produced a sharp diminution in inhibitory properties. A delipidized form of the inhibitor was obtained by ether extraction, and this material produced a single broad band of precipitate in gel immunodiffusion tests.

Characteristics of the Hemagglutinin Produced During Plasmodium lophurae Malaria in Chickens

During the course of Plasmodium lophurae infections in normal chickens, there was a sharp increase in the titer of a hemagglutinin which reacted better with trypsinized than with normal erythrocytes. This hemagglutinin was a typical “cold hemagglutinin” in that it was much more active at 4 C than at 37 C, was found in the macroglobulin fraction of the serum, was eluted from erythrocytes at 37 C, and was easily destroyed by 2-mercaptoethanol reduction. The injection of allogeneic erythrocytes into chickens prior to their exposure to P. lophurae resulted in a coexistent increase in cold hemagglutinin titers and enhanced resistance to parasitemia. Since this antibody was more active against altered erythrocytes than against normal erythrocytes, it may moderate resistance to malarial infections by specifically stimulating phagocytosis of parasitized erythrocytes.

Hemagglutination and hemolysis by : lichen extracts

Twenty-two species of lichens from 10 different genera possessed a hemagglutinin for one or more of human, sheep, horse, cow, rabbit, guinea pig, and chicken erythrocytes. Hemolysins were also detected occasionally, but these were only active at low dilutions. In those species tested, the hemolytic principle was dialyzable; the hemagglutinating agent was not. Preliminary studies have indicated that the lichen hemagglutinins are nonspecific.