Hydrogen peroxide as an oxygen source for immobilized Gluconobacter oxydans converting glycerol to dihydroxyacetone

Summary A flow injection analysis (FIA) system with amperometric detection was developed for measuring hydrogen peroxide which was used as an oxygen source for immobilized cells. A constant concentration of peroxide in the reactor was maintained by processing the analytical signal in a computer programmed as a PI-regulator. The concentration of dissolved oxygen was followed using a commercial Clark-electrode. The simultaneous measurements of hydrogen peroxide and dissolved oxygen are discussed with respect to process control.Conversion of glycerol to dihydroxyacetone by Gluconobacter oxydans immobilized in calcium alginate was used as a model system.Initial specific productivity increased with increasing hydrogen peroxide concentration. However, decreases in viable counts, enzymatic activities and overall productivities were noted. Various techniques for improving operational stability are discussed.     

Tables for estimating the mean of distribution of logarithms of titers based on data with a pooled serum sample.

A table was constructed for use in estimating the mean of distribution of logarithms of titers based on data obtained with a pooled material instead of those with individuals in a sample. A table of standard errors of the estimator was also constructed. Examples showing the utility and applicability of the tables were presented. Several relating problems were discussed.     

Difference in habitat selection by different morphs of the land snail Arianta arbustorum

The behaviour of morphs of Arianta arbustorum has been investigated using a new technique involving a paint which fades in daylight. The technique was used to study the response of different morphs to exposure to sunlight at a homogeneous woodland habitat and a heterogeneous open habitat. The yellow morph showed a significantly higher rate of fading than the brown morph. A mark, release and recapture programme was used to analyse the association between frequencies of different morphs recaptured and not recaptured. In both habitats, there was a general tendency for the frequency of recapture to increase with increasing age in both morphs. Habitat selection resulting from different behaviour of different morphs of A. arbustorum is discussed. Morph frequencies can be related to habitat, the brown morphs of A. arbustorum are significantly less frequent in the open habitat. The behavioural responses of Cepaea hortensis , present with A. arbustorum in two other populations, to the exposure of sunshine were also studied. Climatic selection by solar energy associated with different morphs, species and habitat are also discussed.     

Interaction of arylpiperazine ligands with the hydrophobic part of the 5-HT1A receptor binding site

A flexible docking of a series of arylpiperazine derivatives with structurally different aryl part to the binding site of a model of human 5-HT1A receptor was exercised. The influence of structure and hydrophobic properties of aryl moiety on binding affinities was discussed and a model for ligand binding in the hydrophobic part of the binding site was proposed.     

Bioindicators and accumulators in geobotanical and biogeochemical prospecting of metals

Results of geobotanical and biogeochemical studies carried out on the known lead-zinc deposits of Zawar Mines and Khetri Copper Deposits, India, are discussed. A wild variety of Impatiens balsamina was found to be the most characteristic species on lead-zinc metal dumps, which can be regarded as a local 'bioindicator' for these metals. A number of 'accumulators' for lead, zinc, copper with high BAC values, as well as some 'excluders' are also discussed.     

Growth Promoting Activities of Sclerotinin A and Its Analogs

(±)-Sclerotinin A (Scl. A) showed the same promoting activity as natural (+)-Scl. A, which was isolated as a growth promoting substance of rice seedlings from Sclerotinia sclerotiorum along with sclerin. By the combined use of Scl. A and gibberellin, the synergistic effect on the growth of rice seedlings was noticed as in the case of sclerin. Correlation between the chemical structure and biological activity of Scl. A derivatives and analogs was discussed.     

46,XX/46,XX,8p- mosaicism in a phenotypically normal female

A phenotypically normal female was found to have a chromosome 8 short arm deletion in a low percentage of the cells. The reduced proportion of monosomic cells in relationship with proband's age are discussed.     

Corticosteroids stimulate an increase in phospholipase A2 inhibitor in human serum

A corticosteroid induced increase in a circulating inhibitor of serum phospholipase A2 activity is described. Inhibitor activity was found to be normally present in serum in agreement with the findings of other workers, and this activity was significantly increased by either acute or chronic administration of corticosteroids. The possible relation of this inhibitor to the known inhibitory effects of lipocortin and sphingomyelin on phospholipase A2 activity is briefly discussed.     

Ring chromosome 9 in a newborn male presenting with facial dysmorphia, hypospadias and skeletal abnormalities.

A newborn male presenting with a peculiar appearance, hypertonia, a flexum attitude, hypospadias and skeletal abnormalities was found to bear a r 9 chromosome. A phenotypic distinction between early and late presenting forms is discussed.     

The Dutch consensus on the diabetic foot

In 1996 the Dutch Diabetes Federation installed a consensus committee to formulate practical guidelines for daily practice to prevent, diagnose and treat foot-related complications in patients with diabetes mellitus. A list of definitions was formulated. A new ulcer classification was introduced. Pathophysiology, diagnostic and therapeutic strategies were discussed with special attention for patients with a high risk foot and for prevention instruction. After several rounds of implementation the definite document was unanimously accepted in the fall of 1998.     

Balanced translocation t(17p--; 23p+) in the chimpanzee]

A chimpanzee family was studied, in which the father had a balanced translocation t(17p--; 23p+). The mother showed the normal female chromosome complement. Their daughter had also the normal female karyotype, but with heteromorphic chromosomes 23. A cytogenetic analysis was made using G- and Q-banding techniques and in addition an alkaline silver method for NOR staining. A mechanism of the translocation inheritance is discussed.     

Clinico-genealogical characteristics of hemophilia A in a large inbred kindred

The results of the clinico-genealogical investigation of patients with mild haemophilia A in a large azerbaijanian highly inbred kindred (446 members in VII generations) are presented. Some peculiarities of the disease segregation are discussed. The prevalence of the haemophilia A in the population examined was estimated as about 1:440.     

A low-molecular-weight protein cross-reacting with human liver N-acetyl-β-d-glucosaminidase

Antisera were raised to preparations of hexosaminidase isoenzymes A and B purified from human liver. Protein that cross-reacted with the liver hexosaminidase was detected by an antibody-consumption method. A cross-reacting protein with a low molecular weight (20000) was partially characterized and purified from control human liver. This protein is also present in the liver of patients with Tay-Sachs disease or with Sandhoff's disease. Hexosaminidases A and B gave an immunological reaction of partial identity with the low-molecular-weight protein. The possible identity of the low-molecular-weight cross-reacting protein as a subunit of hexosaminidase is discussed.     

A continuous information theoretic approach to the analysis of cutaneous receptor neurons

Information theoretic and statistical techniques for determining the number of discernible levels in cutaneous receptor neurons are reviewed. Reasons for the large variance in these results are discussed. A new continuous information theoretic analysis technique is presented that overcomes many of the problems in the other methods of analysis discussed. Comparison of this new method of analysis with a statistical technique developed by Schreiner et al. (1978) clearly shows some of the misconceptions that are associated with statistical analysis techniques, and why these problems cannot arise in the new information theoretic technique discussed here.This work was supported, in part, by USPHS grant NS08470 and a Rackham predoctoral fellowship     

Patterns of morphometric and allozyme variation in Aedes albopictus

A survey of microgeographic variation using morphometric and allozyme analyses was conducted on 19 US populations of Aedes albopictus (Skuse) (Diptera: Culicidae), a mosquito that was recently introduced into the US. There was considerable variation within and among populations both in morphometric traits and allele frequencies. A multivariate discriminant analysis enabled the separation of populations into distinct groups; separation among the populations in the morphometric analysis was incomplete with an average of 70% of the individuals being correctly classified. In the allozyme analysis, the discrimination was complete. The populations from Texas were placed close together in the morphometric analysis, whereas in the allozyme analysis a geographic clustering of populations could not be detected. A test of association between the distance matrices derived from the morphometric and allozyme analyses was statistically nonsignificant. The results are discussed in the context of the colonization of the US by A. albopictus. The possible factors underlying the differences in the patterns of variation derived from morphometric and allozyme analyses are also discussed.     

Molybdenum cofactor biosynthesis in Escherichia coli mod and mog mutants.

The molybdopterin content of Escherichia coli mod and mog mutants was estimated by conversion to the form A derivative. The results are in accord with complete phenotypic repair of mod, and incomplete repair of mog, by culture in high concentrations of molybdate. A possible role for Mog as a molybdochelatase is discussed.     

2:12 (p25;q21) translocation classed at first as 2/X]

A balanced translocation t(2;12)(p25;q21) was observed in a girl with mental retardation and several somatic abnormalities. The problems of phenotype-karyotype correlations are discussed.     

The effect of a superhigh dose of ionizing radiation on the content of catecholamine mediators in different areas of the rat brain

In experiments with rats, it was shown that whole-body irradiation of animals with a dose of 500 Gy causes a decrease in the catecholamine mediator content of the truncus cerebri during the first minutes following irradiation. A possible mechanism of the changes observed is discussed.     

New histochemical techniques for the demonstration of carboxyl groups in mucosubstances

Synopsis The histochemical demonstration of the carboxyl groups of mucosubstances was studied by two methods at the light and electron microscopic levels. Conditions for activating carbohydrate carboxyl groups were elucidated from which a modified carbodiimide reaction procedure was worked out. With this procedure several acid mucosubstances could be demonstrated; some were characterized as sialomucoproteins. The mechanism of the carbodiimide reaction is discussed.A method is also discussed for increasing the electron opacity of Alcian Blue-stained mucosubstances with a sulphide-silver reaction.     

Sesqui- and diterpenoids from two Japanese and three European liverworts

A new peroxy muurolane-type sesquiterpenoid was isolated from the ether extract of the Belgium liverwort Scapania undulata, together with three known ent-muurolanes. A new lepidozane-type sesquiterpenoid was isolated from the Japanese Porella subobtusa together with a known santalane- and two africane-type sesquiterpenoids. All structures were determined by means of NMR spectroscopic techniques. The chemosystematics of each species are discussed.