Variation of several erythrocyte enzymes and serum proteins of Indonesians from North Sumatra

Summary Indonesians from North Sumatra were surveyed for erythrocyte enzymes and serum protein variants. The gene frequency of 6PGD^C in 264 Batak was 0.051; in small numbers of other racial groups it ranged from 0.016 to 0.060. The gene frequency of PGM ₁ ¹ in 272 Batak was 0.761; in small numbers of other racial groups it ranged from 0.700 to 0.808. PHI type 4-1 was found once in 271 Batak, and PHI 4-1, PHI 3-1, and PHI 6-1 were each found once in 55 Chinese. No variants were found in the MDH and LDH systems. The Hp¹ gene frequency in 271 Batak was 0.284; in small numbers of other racial groups it ranged from 0.216 to 0.292. The Tf D gene frequency in 262 Batak was 0.044, and that of Tf B was 0.002; in small numbers of other racial groups, Tf D gene frequencies ranged from 0.008 to 0.042. Serum albumin Medan and albumin Kuala Lumpur were found at low frequencies.

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Zusammenfassung Indonesier aus Nord-Sumatra sind auf Erythrocytenenzyme und Serum-Protein-Varianten untersucht worden. Die Genfrequenz von 6PGD^C unter 264 Batak war 0,051; in kleinen Bevölkerungszahlen anderer rassischer Gruppen lag sie zwischen 0,0016 und 0,060. Die Genfrequenz von PGM ₁ ¹ unter 272 Batak betrug 0.761; in kleinen Bevölkerungszahlen anderer rassischer Gruppen lag sie zwischen 0,700 und 0,808. PHI Typ 4-1 fand sich einmal unter 271 Batak, und PHI 4-1, PHI 3-1 und PHI 6-1 wurden je einmal unter 55 Chinesen festgestellt. Im MDH- und LDH-System fanden sich keine Varianten. Die Hp¹-Genfrequenz bei 271 Batak war 0,284; in kleinen Bevölkerungszahlen anderer rassischer Gruppen lag sie zwischen 0,216 und 0,292. Die Häufigkeit des Tf D-Gens bei 262 Batak war 0,044 und die des Tf B-Gens 0,002; in kleinen Bevölkerungszahlen anderer rassischer Gruppen lag die Genfrequenz zwischen 0,008 und 0,042. Das Serumalbumin Medan und-albumin Kuala Lumpur hatten eine geringere Frequenz.

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Supported by the University of California International Center for Medical Research (UC ICMR) through research grant AI 10051 to the Department of International Health, School of Medicine, University of California, San Francisco, from the National Institute of Allergy and Infectious Diseases, National Institutes of Health, U.S. Public Health Service.     

Immunorestoration of old mice by injection of thymus extract: Enhancement of T cell-T cell cooperation in the in vitro antibody response

The effect of injecting a thymus extract (TP-1 or Thy-5) into immunodeficient old mice on the in vitro antibody response of their spleen cells was investigated by techniques suitable for dissecting out T- and B-cell reactivities. The anti-TNP antibody response of HRBC-primed spleen cells from old mice uninjected or injected with TP-1 or Thy-5 was elicited in vitro by TNP-HRBC or TNP-Ficoll. Treatment with TP-1 or Thy-5 was found to induce only a slight increase in the anti-TNP antibody response to both immunogens. The helper activity of HRBC-primed spleen cells from untreated or treated old mice was titrated by adding graded numbers of these primed cells to cultures containing a constant number of normal spleen cells from young mice and the immunogen TNP-HRBC. Under these conditions it was found that both thymus extracts are very effective in restoring T cell-T cell cooperation in the generation of helper cell activity.     

Use of the Most-Probable-Number Technique To Detect Polymyxa betae (Plasmodiophoromycetes) in Soil

The fungus Polymyxa betae is an obligate parasite of the roots of many plants of the family Chenopodiaceae. In the sugar beet, it acts as a vector of beet necrotic yellow vein virus, the agent of a serious disease known as rhizomania. With indirect methods of analysis, such as bioassay, one can establish only the presence or absence, but not the quantity, of P. betae in soil. A new method based on the technique of the most probable number (MPN) of infective units of P. betae present in the soil was developed on the basis of the biological characteristics of this microorganism. Compared with traditional bioassay methods, the MPN method is suitable for determining the contamination level of P. betae in a soil, and it appears promising for the routine analysis of many soil samples, whether they were affected by rhizomania or presumed noninfested. The instrumentation designed especially for the recovery of viable P. betae from soil with the MPN technique is made from commercially available materials, results in a saving of space during sample incubation, and permits this method to be used for any laboratory analysis.     

Changes in rabbit cerebrum and cerebellum gangliosides during postnatal life. A study especially referring to alkali labile gangliosides

The present study deals with the developmental behaviour of cytosolic and membrane-bound gangliosides, especially the alkali labile species, in rabbit cerebrum and cerebellum from birth to 6 months of life. At all ages the amount of cytosolic gangliosides was less than 0.5% of total gangliosides. The proportion of alkali labile gangliosides on the total membrane-bound ganglioside content and the profile of the individual alkali labile gangliosides during postnatal life were different in cerebellum and cerebrum. In cerebellum the proportion of alkali labile gangliosides progressively increased from 4.6% at birth to 16.7% at 6 months; in cerebrum the proportion decreased from 8.9% at birth to a minimum of 5.5% at 10 days, then slowly increased up to 8.1% at 6 months.All the major alkali labile gangliosides in cerebellum, especially O-Ac-GT1b and O-Ac-GQ1b, tended to accumulate during postnatal life. In cerebrum only two alkali labile gangliosides, namely O-Ac-GT1b and a species not yet identified, increased starting from the 10th day of life, while the other ones progressively diminished after birth.     

Benzamidine as a spectroscopic probe for the primary specificity subsite of trypsin-like serine proteinases

Summary Formation and dissociation of the benzamidine: -trypsin adduct is accompanied by reversible spectral changes in the ultraviolet region (between 230 and 300 nm). The pH-independent difference extinction coefficient of the adduct (benzamidine: -trypsin complex minus the free proteinase) is 1.75 mM^–1 cm^–1 at 248 nm. This signal can be used in studies of inhibitor and substrate binding by rapid kinetic techniques. Therefore, following the spectral changes associated with the displacement of benzamidine from the primary specificity subsite, the kinetics of the -trypsin: BPTI complex formation were investigated between pH 2.9 and 7.6 (I = 0.1 M) at 21 ± 0.5 °C. Under all the experimental conditions the -trypsin: BPTI complex formation, examined by benzamidine displacement experiments, may be described in terms of a simple competition event. On the other hand, the very same reaction followed by displacement of another spectroscopic probe, proflavine, appears to involve the ternary proflavine: -trypsin:BPTI adduct (7). The difference between the kinetic processes of -trypsin: BPTI complex formation, observed by using benzamidine and proflavine as reaction indicators, suggests that the two dye molecules bind at non-coincident regions of the proteinase active center. The advantages in using benzamidine as a sensitive probe specific for the S₁ subsite of the recognition center of trypsin-like proteinases, as compared to proflavine, are emphasized.Abbreviations BPTI bovine basic pancreatic trypsin inhibitor (Kunitz inhibitor) - pNGB p-nitrophenyl-p-guanidinobenzoate - NaDodSO₄ sodium dodecyl sulfate     

Confidence limits of the probability of success in animal experiments and clinical studies: A Bayesian approach

PurposeTo determine from the number of trials, n, and the number of observed successes, k the most probable value, the variance and the confidence limits of the probability of success, p, in animal experiments and clinical studies subject to binomial statistics.MethodIn such experiments the probability of success is an unknown parameter. The Bayesian approach to the problem is advocated, based on constructed distribution of the probability of success.ResultsA simple Matlab code for the calculation of the confidence limits according to the proposed method is provided. The most probable, the mean, the variance and the confidence limits are calculated applying the usual definitions of these characteristics.ConclusionThe proposed method works for any number of trials – large and small and all possible values of the number of successes, including k = 0 and k = n, providing exact formulae for the calculation of the confidence limits in all cases.     

Detection of flavonoids in microalgae from different evolutionary lineages

Flavonoids are important secondary plant metabolites believed to be present mainly in land plants. As phenolics were detected previously in microalgae using photometric assays, we wanted to investigate the nature of these phenolics and verify whether flavonoids are present. Therefore, in this study, we used state‐of‐the‐art ultra‐high performance liquid chromatography‐two‐dimensional mass spectrometry (UHPLC‐MS/MS) technology to investigate whether microalgae also contain flavonoids. For this, representative microalgal biomass samples from divergent evolutionary lineages (Cyanobacteria, Rhodophyta, Chlorophyta, Haptophyta, Ochrophyta) were screened for a set of carefully selected precursors, intermediates, and end products of the flavonoid biosynthesis pathways. Our data unequivocally showed that microalgae contain a wide range of flavonoids and thus must possess the enzyme pool required for their biosynthesis. Further, some of the microalgae displayed an intricate flavonoid pattern that is compatible with the established basic flavonoid pathway as observed in higher plants. This implies that the flavonoid biosynthesis pathway arose much earlier in evolution compared to what is generally accepted.     

Susceptibility of selected apple cultivars to the Mediterranean fruit fly

Ceratitis capitata (Wiedemann), the Mediterranean fruit fly, is one of the key pest species affecting deciduous fruit orchards along the Mediterranean coasts. Because of global warming, C. capitata is gradually spreading north and is becoming a major pest of apples. Determining the susceptibility of the main apple varieties grown in the region will serve as a cornerstone to the management of this pest. In this study, we show the results of a field and laboratory no‐choice test conducted to determine the Medfly preferences on different apple cultivars. The seven main varieties of apples (Gala, Red Delicious, Golden Delicious, Granny Smith, Kanzi, Morgen Dallago and Fuji) were tested. The results demonstrate that C. capitata lays eggs on all apple cultivars in both field and laboratory conditions. The Granny Smith, Red Delicious and Morgen Dallago varieties showed the lowest susceptibility in laboratory conditions, (0.75, 1.55, 2 oviposition punctures/fruit, respectively), with significant differences in oviposition compared to the Golden Delicious, Kanzi and Fuji (3.27, 3.31, 3.1 oviposition punctures/fruit, respectively) varieties, which were shown to be the most susceptible to Medfly attack in laboratory conditions. On the other hand, only slight and not statistically significant differences emerged from the field trials. In relation to the physico‐chemical characteristics, the apple cultivars showing the lowest susceptibility (Granny Smith, Red Delicious and Morgen Dallago) had harder peels and pulps and lower sugar contents than the most susceptible cultivars (Golden Delicious, Fuji and Kanzi). These results were also confirmed through evaluation of larval development on different varieties. In fact, Granny Smith, Red Delicious and Morgen Dallago were the three varieties that did not allow adequate larval and adult development and reduced the possibility of the emergence of a new generation.     

Modulation by decitabine of gene expression and growth of osteosarcoma U2OS cells <Emphasis Type="Italic">in vitro</Emphasis> and in xenografts: Identification of apoptotic genes as targets for demethylation

Background  

Methylation-mediated silencing of genes is one epigenetic mechanism implicated in cancer. Studies regarding the role of modulation of gene expression utilizing inhibitors of DNA methylation, such as decitabine, in osteosarcoma (OS) have been limited. A biological understanding of the overall effects of decitabine in OS is important because this particular agent is currently undergoing clinical trials. The objective of this study was to measure the response of the OS cell line, U2OS, to decitabine treatment both in vitro and in vivo.