Changes in cytokeratin expression in epidermal keratinocytes during wound healing

In order to investigate the re-epithelialization process during wound healing, the hair on the back of guinea pigs was shaved and then excisional wounds were made through the entire thickness of the skin. Histological changes were observed and changes in the expression of different cytokeratin polypeptides were examined using an immunohistochemical technique. Immunohisto chemical study revealed that the proliferating and migrating keratinocytes expressed the same cytokeratins as the basal cells of normal epidermis. In addition, the entire epidermis of fairly remote areas from the edges of the wound where no thickening was observed showed a temporarily abnormal staining pattern. The suprabasal cells in the regenerating epidermis temporarily expressed cytokeratins not only specific for suprabasal cells but also specific for basal cells. The cytokeratins expressed in normal basal keratinocytes were also present in the thickened granular layers. These data indicate that the expression of cytokeratins in the epidermal keratinocytes (even in fairly remote areas from the wound edges) changes during wound healing, that the origin of the migrating keratinocytes from the remaining epidermis seems to be the basal cells in the epidermis, and that the appearance of keratohyalin granules is not related to changes in cytokeratin expression.     

Varicella infection in a children's hospital: prevention by vaccine and an episode of airborne transmission

Varicella vaccine was used safely and effectively for preventing ward infection with varicella. Ward infection was experienced 34 times in 5 years between 1977 and 1982. During these ward infections, varicella developed in 4 of 142 patients who received vaccine, 21 of 47 patients who did not receive vaccine and 1 of 9 who received transfusion with vaccine-boostered blood. Of the 142 vaccinated patients, the four in whom varicella developed showed symptoms 3 to 10 days after vaccination, indicating that vaccination had been too late. Details of a ward infection with varicella by airborne transmission and its prevention by vaccination are presented.     

Multiple redundant circadian oscillators within the isolated avian pineal gland

Summary The avian pineal gland contains a circadian pacemaker that oscillates in vitro. Using a flow-through culture system it is possible to measure melatonin production from very small subsections of an individual gland. We have used this technique to attempt to localize the oscillators in the pineal. Progressive tissue reduction did not affect the rhythmicity of cultured pineals. Multiple pieces (up to eight) from a single pineal all were capable of circadian oscillation — establishing directly that a pineal gland contains at least eight oscillators. All pineal pieces were responsive to light, and single light pulses shifted the phase of the melatonin rhythm. Because pieces equivalent to less than one per cent of the whole gland were rhythmic and because the capacity for oscillation was distributed throughout the gland, an individual pineal appears to be composed of a population of circadian oscillators.     

A unique electrophoretic slow-moving glucose 6-phosphate dehydrogenase variant (G6PD Asahikawa) with a markedly acidic pH optimum

Summary A new glucose 6-phosphate dehydrogenase (G6PD) variant associated with chronic nonspherocytic hemolytic anemia was discovered in Japan. The patient showed hemolytic crises after upper respiratory infections. The enzyme activity was about 3.8% of the normal. The partially purified enzyme revealed slow anodal electrophoretic mobility, high Km NADP, marked thermal-instability, and increased affinity for a substrate analogue (deamino-NADP). A particular characteristic of this enzyme was a biphasic pH curve with a greatly increased activity at low pH values. From these results, this variant was clearly different from hitherto observed G6PD variants, and was designated G6PD Asahikawa.     

The reactions of phenylglyoxal and related reagents with amino acids.

1. The reaction of phenylglyoxal (PGO), glyoxal (GO), and methylglyoxal (MGO) with amino acids were investigated at mild pH values at 25 degrees. These aldehydes reacted most rapidly with arginine and the rate of reaction increased with increasing pH values. Histidine, cystine, glycine, tryptophan, asparagine, glutamine, and lysine reacted with these aldehydes at significant but various rates, depending on the pH and the kind of the reagent used. The reactions with these amino acids seemed to involve both the alpha-amino groups and the side chain groups, and no significant reaction appeared to occur with the side chain alone except with those of arginine, lysine, and cysteine. These reagents were similarly reactive with the guanidinium group of arginine, but PGO appeared to be much less reactive with the epsilone-amino group of lysine than MGO and GO. The other ordinary amino acids were very much less reactive or did not react at all with these reagents, with the exception of cysteine. 2. Di-PGO-L-arginine was prepared from Nalpha-benzyloxycarbonyl-L-arginine, and di-PGO-methylguanidine from methylguanidine, and the stoichiometry of the reaction of two PGO molecules with one guanidino group was confirmed. A glyoxal derivative of L-arginine (GO-arginine) was prepared by reaction of glyoxal with arginine. GO-arginine was fairly unstable, especially at higher pH values. A similar derivative (MGO-arginine) was also found to be formed by reaction of MGO with L-arginine, and was similarly unstable. These derivatives, however, did not regenerate arginine upon acid hydrolysis.     

Attack and defensive behaviour in the albino rat

Attack of dominant colony males of an albino rat (Rattus norvegicus) strain, on introduced strangers, produced a non-random distribution of bites, with ventral trunk virtually never bitten. Also, vibrissae-contact of attacker and defender interfered with bites to the defender's head and upper back. The specific agonistic reactions of attacking and defending rats appeared to involve strategies based on these limitation on attack: defenders utilized 'boxing' and lying 'on-the-back' behaviour, which interposed ventral trunk and vibrissae between attacker and defender. In turn, the 'lateral display' permitted attackers to circumvent the defender's behaviour. Limitations on attack therefore appeared to underlie the specific agonistic behaviour of both attacking and defending rats.     

Molecular adaptability of carp myosin: a study of some physico-chemical properties and their comparison with those of rabbit myosin.

During thermal inactivation, the addition of as low as M urea resulted in the reduction of delta G identical to barrier of the inactivation of carp myosin Ca2+-ATPase, whereas that of rabbit myosin remained unaffected. In the absence of urea, a four-hour incubation of carp myosin was accompanied by the release of light chains at 30 degrees C, a value 10 degrees C lower than that for rabbit myosin. Electron micrographs revealed that carp myosin forms artificial thick filaments, which were uniform in size and may differ in a few details from those of rabbit. Not only that helical content of carp myosin was about 4% less than those of rabbit myosin, but it showed more sensitivity to thermal and urea denaturation; and its reversibility upon subsequent cooling or removal of urea was rather poor. The loss in helicity of myosins by urea was a concentration- and temperature-dependent biphasic reaction, with the most obvious effect observed on carp myosin. That carp myosin has increased tendency of unfolding in urea solutions was confirmed by viscosity data and the exposure of thiols also. Even in the absence of urea more SH groups of carp myosin were incorporated by DTNB, and more epsilon-amino groups reacted with NQS. Carp myosin remained in solution till the modification of about 52 surface myosin remained in solution till the modification of about 52 surface amino groups, whereas no precipitation effect was noted in case of rabbit myosin. Neither amino-acid composition nor some parameters derived from it, such as average hydrophobicity polarity index and number of polar side chains, revealed any difference pertinent to the relative stability of the two myosins. On the contrary, the contractile efficiency of carp myosin in the near physiological range was high and thus inversely related with the thermostability. This relationship along with the above evidence has been regarded to demonstrate the adaptability of carp myosin through a loose molecular conformation, which has probably been achieved by the addition of weak interactions in the course of evolution.     

Isolation and identification of 25-hydroxy-24-oxocholecalciferol: A metabolite of 25-hydroxycholecalciferol

A metabolite of 25-hydroxycholecalciferol has been isolated in pure form from chicken kidney homogenates. It has been identified as 25-hydroxy-24-oxocholecalciferol by means of ultraviolet absorption spectrophotometry, mass spectrometry, infrared spectrometry, nuclear magnetic resonance spectrometry, and specific chemical reactions.     

Phlegmacins and anhydrophlegmacinquinones: Dimeric hydroanthracenes from seedlings of Cassia torosa

From seedlings of Cassia torosa four dimeric hydroanthracenes have been isolated. Two, a pair of atropisomeric dimers consisting of two molecules o