Apolipoprotein (apo) B and apoII gene expression are both estrogen-responsive in chick embryo liver but only apoII is estrogen-responsive in kidney

Estrogen regulates the hepatic synthesis of a variety of proteins required for egg yolk production in oviparous vertebrates. In chickens, two of these proteins, apolipoprotein (apo) B and apoII, comprise the major protein components of specialized very low density lipoprotein particles that transport triacylglycerols and cholesterol to the developing egg yolk. In the adult, apoB is synthesized constitutively in liver, small intestine, and kidney but is estrogen-responsive only in the liver. In this work we have examined the embryonic expression of the apoB and apoII genes in yolk sac, liver, kidney, and small intestine. The 14 kb apoB mRNA was first detected at day 3 of development in vascular yolk sac, a tissue involved in the transfer of yolk lipids into the embryonic circulation. Constitutive apoB mRNA expression was detectable in liver at day 6.5 and in kidney at day 7.5, but in intestine was barely detectable before hatching. The hepatic apoB gene acquired estrogen-responsiveness at day 6.5 and its hormone-dependent expression increased throughout development in concert with the estrogen-responsive expression of the apoII gene. In contrast, the constitutively expressed apoB gene in kidney remained unresponsive to estrogen. Surprisingly, the apoII gene was found to be responsive to estrogen in both the embryonic kidney and small intestine. ApoII mRNA induction by estrogen in kidney at day 11 was at 10% of the level in the liver but estrogen-responsiveness decreased later in development and was low in the adult.(ABSTRACT TRUNCATED AT 250 WORDS)     

Conservative prediction of time to Clostridium botulinum toxin formation for use with time-temperature indicators to ensure the safety of foods

Integrating-type time-temperature indicators (TTIs) may be utilized to warn food processors and consumers about storage conditions that may have rendered a food potentially hazardous. As an example of how integrated TTIs could be manufactured to emulate an infinite set of time-temperature situations, a set of conditions which have supported C. botulinum growth and toxin production was compiled. The time-temperature curve representing conservative times required for toxin formation was constructed with data from literature relating to toxin formation as a function of temperature in any media or food product. This set of critical time-temperature data is fit by a conservative empirical relationship that can be used to predict combinations of incubation times and storage temperatures that represent a potential health risk from C. botulinum in foods. A TTI could be constructed to indicate deviation from such a given set of conditions to bring attention to foods that may have been exposed to potentially hazardous temperatures with respect to C. botulinum toxin formation.     

A conundrum in molecular toxicology: molecular and biological changes during neoplastic transformation of human cells

The process of multistage carcinogenesis lends itself to the concept that the effects of carcinogens are mediated through dose-related, multi-hit, linear changes. Multiple in vitro model systems have been developed that are designed to examine the cellular changes associated with the progression of cells through the different stages in the process; however, these systems may have inherent limitations due to the cell lines used for these studies, the manner of assessing the effects of the carcinogens, and the subsequent growth and differentiation of the exposed cells. Each of these variables results in increasing levels of uncertainty relative to the correlation of the events with the actual process of human tumor development. Therefore, the prediction of the ultimate effect of any carcinogen is difficult. Moreover, relationships between individual biological endpoints resulting from carcinogen treatment appear at best to be approximations. The presence of an activated carcinogen inside the cell can give rise to multiple outcomes, only some of which may be critical events. For example, site-specific modification of the 12th and 13th codons of H-ras is different than that in the adjacent 14th and 15th codons. It is interesting to speculate what effect these differences might have on a biological outcome, e.g., transformation to anchorage-independent growth. The use of different model systems to examine the effects of activated carcinogens also creates additional problems. Comparisons of in vitro transformed cells with similar cells isolated from human tumors indicate that the culture environment appears to influence the expression of a particular phenotype, in that human tumor cells in culture express many of the same parameters as those found in cells transformed with carcinogens in vitro. If the process of transformation is linear, then less aggressive phenotypes should progress to a more aggressive transformed stage. However, in carcinogen-transformed human cells, the populations exhibit phenotypic diversity in that many of the transformed cells differentiate and fail to continue to divide in culture. Historically, we have assumed only a limited role for epigenetic modulation of molecular changes that occur during progression; however, our data suggest quite strongly that nonmalignant tumor populations can be converted to a more malignant phenotype without additional mutations taking place and, conversely, malignant populations can be downregulated to a nontumorigenic phenotype. Tumor cell plasticity is not only a fundamental characteristic of diverse types of human tumors, but also appears as an integral characteristic of carcinogen-transformed cells in vitro.     

Isolated agenesis of the mastoid antrum

The first isolated case of agenesis of the mastoid antrum, previously only described in association with the congenital syndromes trisomy 13 and mandibulofacial dysostosis, is reported. The loss of this important surgical landmark may result in disorientation and iatrogenic trauma. The surgeon must be aware of its existence, and where it is suspected the middle fossa dura should be exposed and followed posteriorly until the lateral sinus is encountered.     

Mutational analysis of a satellite phage activator

A culture medium, named olive juice broth, which resembles the natural environment of Lactobacillus plantarum in the traditional Spanish-style green olive fermentation was obtained from green olives. In this medium, the bacteriocin-producing L. plantarum LPCO10 strain was able to produce bacteriocin throughout the incubation time (15 days). Bacteriocin purification from olive juice broth was achieved by a protocol including ammonium sulphate precipitation of cell-free, L. plantarum LPCO10 culture supernatants, and cation-exchange, hydrophobic-interaction and reversed-phase chromatographies. In a series of mixed cultures in olive juice broth, L. plantarum LPCO10 was able to dominate the bacteriocin-sensitive L. plantarum 128/2 strain, whereas the non-bacteriocin-producing, LPCO10 strain derivative, L. plantarum 55-1 strain did not show such capability. These results indicated that olive juice broth may be a valuable experimental substitute for olive fermentation brine in gaining more knowledge about the role of the bacteriocin-producing L. plantarum strains in the control of the Spanish-style green olive fermentation.     

Therapist responsiveness to client interpersonal styles during time-limited treatments for depression

A 4-kb DNA segment of Tenebrio molitor (Insecta, Coleoptera) genomic DNA containing two larval-pupal cuticular genes has been cloned and sequenced. These genes, transcribed in opposite directions, are related in DNA sequence and the proteins encoded are very similar. Each of them contains a single intron located inside the sequence encoding the signal peptide, and a conserved sequence at -200 bp from the mRNA start position. These similarities in sequence suggest that these genes have evolved by duplication followed by diversification and that they are members of a family of genes with a common ancestry. They are the first example of clustered genes in Tenebrio molitor.     

25-hydroxycholecalciferol serum levels in patients with Crohn's disease

In 37 patients with Crohn's disease the 25-hydroxycholecalciferol (25-HCC) serum level, serum concentration of calcium and inorganic phosphate, and the enzyme activity of alkaline phosphatase were measured. Furthermore the activity index of Crohn's disease was determined in every patient. There was no statistically significant difference of 25-HCC serum levels in these patients compared to a healthy control group. Correspondingly most patients showed normal alkaline phosphatase enzyme activity and normal serum concentration of calcium and inorganic phosphate. No correlation between 25-HCC concentration and site of inflammation or activity index was found.     

Isolation of canine prolactin by polyacrylamide gel electrophoresis

The electrophoretic mobility of prolactin obtained from canine pituitary extract was studied with the aid of polyacrylamide disc electrophoresis. Using a preparative gel electrophoretic system the immunoreactive material was purified on a quantitative scale which was then used to develop a homologous radioimmunoassay for canine prolactin. The radioimmunoassay system was able to detect prolactin in the plasma of dogs after the administration of agents which would be expected to affect prolactin secretion.     

The implementation of case statements in Pascal

This paper examines the probable implementations of the case statement in Pascal, and analyses their consequences. A particular implementation for the Burroughs B6700/7700 series illustrates the necessary investigations. The techniques, although not new, are brought together to serve as a stimulus to improving the implementation of case-statements in other compilers for Pascal, and to provide ideas for implementors. The architectural limitations of even high-level computers in implementing the case statement are briefly discussed.