Induction of hyaluronic acid synthetase by estrogen in the mouse skin

Hyaluronic acid synthetase activity was measured in male mouse skin following the topical application of estradiol in vivo. The enzyme activity increased in parallel with the hyaluronic acid content of the skin, and showed a similar response in the skin of ovariectomized female mice. The increase in enzyme activity was reduced by the anti-estrogen agents, tamoxifene citrate and clomiphene citrate, which block competitively the binding of estrogen to the estrogen receptor. The increase in hyaluronic acid synthetase activity was also reduced by topical application of cycloheximide or by subcutaneous injection of actinomycin D. The results suggest that the stimulation of hyaluronic acid synthesis in mouse skin in response to estrogen treatment is mediated through estrogen receptors and involves the induction of the enzyme hyaluronic acid synthetase.

Galactosyltransferase activities in human sera of various diseases

Recently galactosyltransferase has been noted as a new tumor marker. In this report galactosyltransferase activity was measured in sera of various diseases including malignant tumors and the levels of the enzyme activities were compared. The levels of the enzyme were higher in sera of malignant tumors and liver diseases than those in sera of other diseases. In malignant tumors little organ specificity was found with respect to the levels of galactosyltransferase activities. The levels of the enzyme were considered to have no relation to carcinoembryonic antigen or alpha-feto protein. On the other hand, in liver diseases the levels of the enzyme were correlated to the severity of liver damage. Therefore, it is reasonable to presume that the elevation of serum galactosyltransferase activity is caused chiefly by malignant tumors and liver damage.

Clinical isolate of Pseudomonas aeruginosa that degrades salicylate by the ortho pathway

A clinical isolate of Pseudomonas aeruginosa was found capable of utilizing salicylate by the salicylate hydroxylase and beta-ketoadipate pathway.

Nucleotide binding to isolated alpha and beta subunits of proton translocating adenosine triphosphatase studied with circular dichroism

The catalytic and allosteric sites of proton translocating adenosine triphosphatase (ATPase) were studied by measuring the binding of nucleotides to the ATPase, and its alpha and beta subunits purified from thermophilic bacterium PS3, with a circular dichroic spectrometer. In contrast to mesophilic ATPases, this thermophilic enzmye contained no tightly bound nucleotides, and its subunits were stable after their purification. These properties were advantageous for analyzing both catalytic and allosteric sites. The former site showed rapid and loose binding, but the latter slow (t 1/2 = 1 h, for ADP) and tight binding. When a nucleotide was bound, the beta subunits showed a negative ellipticity at 275 nm corresponding to a tyrosyl residue, while the alpha subunits showed an ellipticity change corresponding to the absorption curve of the bound nucleotide. This difference enabled us to distinguish the binding sites in ATPase. At a low concentration, ADP selectively bound to alpha subunits in the ATPase, while at a high concentration, it bound to both subunits. This finding suggests that the tight binding sites are located in the alpha subunits. Although ADP and ATP bound to both the purified alpha and beta subunits, CTP did not bind to beta but only to alpha subunits, and ITP bound to beta but hardly to alpha. These nucleotide specificities also supported the idea that the catalytic sites are located in the beta subunits and the allosteric sites are located in the alpha subunits.

Intersubunit interactions in proton-translocating adenosine triphosphatase as revealed by hydrogen-exchange kinetics

The rates of hydrogen-deuterium exchange in the peptide groups of the alpha and beta subunits and the alpha-beta subunit complex of proton-translocating adenosine triphosphatase from the thermophilic bacterium PS3 were examined. The exchange was found to be much slower in the isolated beta subunit than in the isolated alpha subunit. This has been taken as indicating that the structure of the beta subunit is tighter than that of the alpha subunit. Adenosine 5'-triphosphate (ATP) caused tightening of a relatively tight portion of the alpha subunit and of a relatively loose portion of the beta subunit. When the alpha and beta subunits are brought into contact, tightening of the alpha subunit, but not the beta subunit, occurs. The effect of ATP on the structure of the beta subunit is more pronounced in the presence of the alpha subunit than in its absence. These findings support the idea proposed previously that the alpha subunit has an allosteric site and the beta subunit a catalytic site and that the conformation of the beta subunit is controlled by the alpha subunit.

Intrapericardial aneurysm of the left atrial appendage

A 24-year-old housewife with congenital aneurysm of the left atrial appendage underwent a successful operation for its removal. Operation, using cardiopulmonary bypass, is indicated in all patients with atrial aneurysm. The procedure has proved uniformly safe and successful.

The mechanism of estrogen-induced increase in hyaluronic acid biosynthesis, with special reference to estrogen receptor in the mouse skin

The increase in hyaluronic acid and water contents induced by estradiol treatment in the mouse skin was dependent on dose and the number of treatments of estradiol. The anti-estrogen administered together with estradiol blocked the increase in hyaluronic acid content produced by treatment with estradiol alone. It was suggested that the anti-estrogen may act as an antagonist by competing for the cytoplasmic estrogen receptor on increase in hyaluronic acid synthesis. It was observed that the sensitivity in increase in hyaluronic acid biosynthesis by estradiol was related to the age of the mouse and the content of the cytoplasmic estrogen receptor in the mouse skin. It was suggested that there was a possible relationship between the increase in hyaluronic acid and cytoplasmic estrogen receptor in the mouse skin.

Neuronal depletion of cerebellum in late infantile metachromatic leukodystrophy

The cerebellums of two children with late infantile metachromatic leukodystrophy were investigated by light and electron microscopy. These observations showed that the morphological abnormalities were comprised not only of severe demyelination and presence of metachromatic granules but also marked loss of Purkinje cells and granule cells. The depletion of Purkinje cells is considered to have resulted from demyelination of their myelinated axons. On the other hand, the reduction of granule cells is considered to be caused by the loss of Purkinje cells and presynaptic elements such as mossy fibers and glomerular collaterals of climbing fibers. The depletion of these neurons induced destruction of synaptic connection in the cerebellum.

Studies on polypeptide-chain-elongation factors from an extreme thermophile, Thermus thermophilus HB8. 3. Molecular properties

Molecular properties of the polypeptide chain elongation factors from Thermus thermophilus HB8 have been investigated and compared with those from Escherichia coli. 1. As expected, the factors purified from T. thermophilus were exceedingly heat-stable. Even free EF-Tu not complexed with GDP was stable after heating for 5 min at 60 degrees C. 2. GDP binding activity of T. thermophilus EF-Tu was also stable in various protein denaturants, such as 5.5 M urea, 1.5 M guanidine-HCl, and 4 M LiCl. 3. Amino acid compositions of EF-Tu and EF-G from T. thermophilus were similar to those from E. coli. On the other hand, amino acid composition of T. thermophilus EF-Ts was considerably different from that of E. coli EF-Ts. 4. In contrast to E. coli EF-Tu, T. thermophilus EF-Tu contained no free sulfhydryl group, but one disulfide bond. The disulfide bond was cleaved by sodium borohydride or sodium sulfite under native conditions. The heat stability of the reduced EF-Tu . GDP, as measured by GDP binding activity, did not differ from that of the untreated EF-Tu . GDP. 5. T. thermophilus EF-Ts contained, in addition to one disulfide bond, a sulfhydryl group which could be titrated only after complete denaturation of the protein. 6. Under native conditions one sulfhydryl group of T. thermophilus EF-G was titrated with p-chloromercuribenzoate, while the rate of reaction was very sluggish. The sulfhydryl group appears to be essential for interaction with ribosomes, whereas the ability to form a binary GDP . EF-G complex was not affected by its modification. The protein contained also one disulfide bond. 7. Circular dichroic spectra of EF-Tu from T. thermophilus and E. coli were very similar. Binding of GDP or GTP caused a similar spectral change in both. T. thermophilus and E. coli EF-Tu. On the other hand, the spectra of T. thermophilus EF-G and E. coli EF-G were significantly different, the content of ordered structure being higher in the former as compared to the latter.

Chromosomal location of genes participating in the degradation of purines in Pseudomonas aeruginosa

Genetic mapping of the genes (puu) that encode the enzymes catalysing degradation of purines in Pseudomonas aeruginosa strain PAO has been carried out. Mutants that are deficient in adenine deaminase (puuA), guanine deaminase (puuB), xanthine dehydrogenase (puuC), uricase (puuD), allantoinase (puuE), and/or allantoicase (puuF) were isolated and used for the genetic study. Conjugation by FP5 factor and generalized transduction by phage G101 gave the following map locations of these six genes on the chromosome: hisI--puuB--hisII; trpA,B--puuA--ilv202; met9011--catA1--tyu--nar9011--(puuC, puuD, puuE)--puuF. A close linkage among the puuC, puuD and puuE was demonstrated by the transduction.

Thermotropic transition in the states of proteins in sarcoplasmic reticulum vesicles

Interaction between protein and phospholipid molecules in sarcoplasmic reticulum (SR) was studied by measurement of the conformational fluctuation of the protein using the kinetics of the hydrogen-deuterium exchange reaction. It was revealed that the state of SR ATPase undergoes a phase transition at about 18 degrees C with boundary lipids, corresponding to a discrete change in the activation energy of the Ca2+, Mg2+-ATPase reaction.

Structural fluctuation of the polypeptide-chain elongation factor Tu. A comparison of factors from Escherichia coli and Thermus thermophilus HB8

The kinetics of hydrogen-deuterium exhcange in the polypeptide chain elongation factor Tu (EF Tu) from Escherichia coli and that from Thermus thermophilus HB8 has been examined in aqueous solutions at various pH and temperatures by means of infrared absorption measurements. The free EF-Tu from E. Coli has a greater reaction rate at all pH values and at every temperature than that of the GTP-bound or GDP-bound EF-Tu. The free EF-Tu from T. thermophilus, on the other hand, has an alomst equal reaction rate to that of EF-Tu-GDP in the temperature range 38-55 degrees C. For the peptide NH groups belonging to a medium-labile kinetic class, a small but definite difference in the rate of exchange reaction was observed between EF-Tu-GDP and EF-Tu-GTP for both E. coli and T. thermophilus. For less labile peptide NH groups, on the other hand, the rate of the exchange reaction with EF-Tu-GDP from T. thermophilus is only slightly affected by the pH of the solution at 38 degrees C and 45 degrees C, while the rate constant(k) with E. coli EF-Tu-GDP is pH-dependent (log k oc pH). For T. thermophilus EF-Tu, heat stability measurements, kinetics of the rates of GDP and GTP dissociation, and circular dichroic measurements have also been made. The molecular basis for the thermostability of T. thermophilus EF-Tu is discussed.

Ventricular reciprocal rhythm occurring in succession in a patient with a variant angina pectoris

A clinical surface electrocardiogram (ECG) in which ventricular reciprocal rhythm occurred occasionally three times and probably seven times in succession together with paroxysmal ventricular tachycardia and ventricular extrasystoles in competition with sinus rhythm causing incomplete A-V dissociation is described. An ECG tracing of ventricular reciprocal rhythm occurring in succession has never been reported previously as far as can be ascertained from published reports.

Characterization of a heat-shock process for reduction of the nucleic acid content of Candida utilis

A process for reducing the nucleic acid content of Candida utilis NRRL Y900 has been developed. The optimal process consists of heating the cells suspended in spent medium initially at pH 4.0 for various times at three different temperatures. Initially a heat-shock at 68 C for 1 to 3 sec is performed followed by incubation for 1 hr at 45 to 50 C and for a 2nd hr at 52 to 55 C. The distribution of degradation products has been characterized. Initially 90% of the nucleic acids were in a polymerized form (extractable by hot perchloric acid). After 30 min, much of this material was hydrolyzed but remained within the cell (extractable by cold perchloric acid). After 2 hr, most of the hydrolysis products leaked into the surrounding medium with only a small amount of low-molecular-weight material remaining within the membrane. Predominantly 3'-mononucleotides accumulated within the cell and eventually leaked from the cell.