Search

The effect of salmon calcitonin (SCT) on the number of T lymphocytes accumulating in air pouch lining membranes produced on the back of Wistar rats was studied. SCT was given from day 0 through day seven following the air cavitation by daily injections of 2.5–20 μg/kg directly into the air cavity. Compared with saline controls, treatment with SCT caused a clear reduction in percentage of T lymphocytes, T helper cells and T non-helper subset in the synovial-like air pouch lining as revealed by FITC-labeled monoclonal antibodies and quantified by flow cytophotometric measurements. This effect may be due to a reduction in local vascular permeability caused by SCT.

Fullerene powder mixtures with different C60/C70 ratios have been analyzed by a variety of techniques, and results have been compared. The fullerence mixtures have been characterized as solutions in n-hexane by high-pressure liquid chromatography (HPLC) and UV-VIS spectroscopy. Thin films of fullerenes on Au(111) have been prepared from the mixtures by sublimation. The sublimation process has been studied by simultaneous thermogravimetric and differential thermal analyses. Thin fullerene films on Au(111) have been investigated by scanning tunneling microscopy (STM). The STM images show primarily two types of ballshaped molecules arranged in a lattice with hexagonal symmetry (fcc(111) face, nearest neighbour distance: 1 nm). The two species differ in diameter. STM images of films made of mixtures of different C60/C70 ratios show that C70 molecules display a larger apparent diameter (0.8 nm) and corrugation than C60 molecules (0.7 nm). The C60/C70 ratios obtained by counting the corresponding molecular species in the STM images of the thin films are compared to the C60/C70 ratios determined by HPLC on hexane solutions of the mixtures. The observed differences might be explained by different rates of sublimation for the two species. The STM images reveal film defects (vacancies and boundaries) and dynamic processes (displacement of C70 molecules and vacancies). In films prepared to have a C60 coverage of less than one monolayer, stable structural units of the C60(111) surface consisting of three or seven C60 molecules are revealed by STM. Occasionally, substructure within individual fullerene molecules is observed.

For 2 years bone density changes in patients with rheumatoid arthritis were monitored to determine the effect of low dose corticosteroid treatment. Sixteen berimenopausal females were studied. Of these nine were treated with 5 to 20 mg prednisone per day and seven had no steroids. The differential effects on trabecular bone density and on cortical bone in the radius and the tibia were examined with high precision peripheral quantitative computed tomography (QCT). Steroid therapy did hot influence cortical bone loss and had only a minor influence on trabecular bone density. Of greater importance was the influence of estrogen depletion. Corticosteroids and estrogen depletion, however, cannot explain fully the yearly loss of 5.7% in the trabecular and 4% in the cortical bone of the radius.

The three alcohol dehydrogenase genes in the mouse are subject to developmental, hormonal, and genetic control as revealed by variation in expression among inbred strains. The primary purpose of this study was to determine the mechanism by which androgen regulates the expression of the Adh-1 gene in kidney. In addition, the fold-induction in several inbred strains was examined in a search for possible genetic variation in the induction process, and Adh-1 expression in several tissues was studied. Testosterone treatment of female mice results in a 10-12-fold increase in alcohol dehydrogenase activity and a corresponding increase in the rate of enzyme synthesis accounts for this induction. The induction of Adh-1 mRNA after androgen treatment is sufficient to account for the induction in enzyme synthesis. An increase in Adh-1 transcription accounts for a substantial part of the increase in Adh-1 mRNA level following androgen simulation. This conclusion was reached using nuclear “run-on” assays, in vivo labeling, and a kinetic analysis of Adh-1 mRNA accumulation and loss in response to hormone. This induction requires androgen receptor. The fold induction by androgen of Adh-1 mRNA is similar in eight inbred mouse strains. There is almost a 100-fold variation in Adh-1 mRNA concentrations among various mouse tissues. Tissues with lowest level of expression are brain and heart, while liver and adrenals have the highest content of Adh-1 mRNA.

Summary Three hundred patients of the Swiss Rheumatoid Arthritis Patient Union were asked by questionnaire whether they had any adverse reaction from food. Of the 159 replies 52 gave a positive history. Thirty-five patients could be further evaluated. Six patients, who gave the mose typical history of allergy, were investigated clinically, with laboratory tests and technetium-scintigramme after food challenge. There was no sign of an immunologic reaction in any of the measured parameters. The other patients were interviewed a second time with an extensive allergological questionnaire. None of the food intolerances could be substantiated.

We previously reported that infection of chicken embryonic neuroretina cells with Rous-associated virus type 1 leads to the frequent occurrence of spliced readthrough transcripts containing viral and cellular sequences. Generation of such chimeric transcripts constitutes a very early step in oncogene transduction. We report, here, the isolation of a c-mil transducing retrovirus, designated IC4, which contains a highly mutated U3 sequence in which 48% of A is converted to G. Functional analysis of this variant U3 indicated that these mutations do not impair viral transcription and replication; however, they abolish functioning of its polyadenylation signal, thus allowing readthrough transcription of downstream cellular sequences. On the basis of these results, we designed a nonreplicative retroviral vector, pIC4Neo, expressing the neomycin resistance (Neo(r)) gene under the control of the IC4 long terminal repeat. Infection of nondividing neuroretina cells with virus produced by a packaging cell line transfected with pIC4Neo occasionally resulted in sustained cell proliferation. Two independent G418-resistant proliferating cultures were found to express hybrid RNAs containing viral and cellular sequences. These sequences were characterized by reverse transcription-PCR and were identified in both cultures, suggesting that proliferation was correlated with a common integration locus. These results indicate that IC4Neo virus functions as a useful insertional mutagen and may allow identification of genes potentially involved in regulation of cell division.

Osteoarthritis is a common disease that constitutes a considerable socioeconomic burden. So far no radiological procedure was available that allowed the disease to be detected in an early stage. Monitoring disease progression and efficacy of therapeutic procedures was also not possible. We present a measuring procedure and describe evaluation tools that are based on 3D computed tomography. The procedure provides quantitative data on pathological features known to be associated with osteoarthritis such as subchondral sclerosis, osteophytes, joint space narrowing, and bone lesions. It is fully three dimensional, the results are operator independent and describe global as well as local parameters. Changes in these parameters are evaluated from differential images. For that purpose a 3D matching procedure based on translation and rotation-specific correlation techniques is used that allows a repositioning of the bone objects with a mismatch of less than 0.3 mm with regard to translations and 0.250 with regard to rotations. The use of the new tools for measurement, repositioning and evaluation is illustrated with the results from a clinical study. Patients with mild osteoarthritis of the knee joint, healthy controls and osteoporotic patients, all in the same age range of 60 to 75 years, were examined during three years. The cortical to trabecular bone ratio describing subchondral sclerosis proved to be especially helpful to distinguish early osteoarthritic cases from age matched controls. Disease progression is best shown by the increase in the number of detected bone lesions, a reduction of the mean distance between femur and tibia and an increase in the cortical to trabecular bone ratio. Hence the presented procedure appears to have a great potential in diagnosis and treatment monitoring of osteoarthritis.

The present study has been designed to work out the factors regulating the fasting serum levels of trypsin-like immunoreactivity in chronic pancreatitis. One hundred patients with chronic pancreatitis have been included and studied during a painless phase of the disease. No relationships have been observed between serum trypsin-like immunoreactivity and the presence of pancreatic calcifications. Serum immunoreactive trypsin levels showed a gradual decline parallel to the progressive impairment of bicarbonate and enzyme (trypsin and chymotrypsin) outputs in duodenal aspirates during pancreatic secretory studies. Therefore, serum trypsin-like immunoreactivity levels are thought to reflect the functional capacity of the exocrine pancreas. Reduced levels of trypsin-like immunoreactivity were detected in almost all patients with diabetes and steatorrhea. However, the finding of low levels also in a minority of chronic pancreatitis patients with normal endoscopic retrograde cholangiopancreatography or pancreatic secretory tests points to other factors which, in addition to the atrophy of the pancreatic parenchyma, may influence the circulating levels of trypsin-like immunoreactivity in chronic pancreatitis.

The molecular basis of the alcohol dehydrogenase (ADH)-negative deer mouse (Peromyscus maniculatus) has been investigated. Several classes of mammalian ADHs have been recognized based upon biochemical and structural properties. ADH cDNA clones identified by hybridization to a mouse class I ADH cDNA clone were obtained from a deer mouse ADH-positive liver cDNA library. This cDNA has been identified as being a class I sequence and represents the deer mouse Adh-1 gene. An additional cDNA sequence identified in both the ADH-positive and -negative deer mouse cDNA libraries was identified by weak cross-hybridization to the mouse cDNA. This cDNA encodes an amino acid sequence representing a new class of mammalian ADH, and the deer mouse gene for this ADH is named Adh-2. ADH-negative deer mice do not produce mRNA, that is detected by the Adh-1 cDNA probe. However, both stocks of deer mice produce high levels of Adh-2 mRNA in liver. Southern analysis using an essentially full-length Adh-1 cDNA probe has shown that the Adh-1 gene is deleted in the ADH-negative mice. Biochemical analysis of enzyme activity suggests at least three ADH polypeptides are expressed in different tissues and have somewhat different substrate specificities, as in the mouse.

Alcohol dehydrogenase (EC 1.1.1.1; alcohol:NAD+ oxidoreductase) activity varies 2-fold in liver extracts prepared from different inbred mouse strains. The strain-specific variation is not present in kidney extracts of male mice and is developmentally specific in the liver, occurring in mice 25 days of age and older. Neither electrophoretic nor heat lability properties of the enzyme from 15-day-old animals are different from the enzyme in adult mice. Analysis of genetic crosses and recombinant inbred lines confirms that a single genetic locus, designated Adh-1-t, with additive alleles has a major effect in controlling the temporal difference in enzyme activity between strains. This enzyme has been purified from mouse liver, and antibodies to the enzyme have been produced in a goat. Quantitative immunoprecipitation reveals that a given quantity of antibody immunoprecipitates equivalent protein and enzyme activity from liver extracts prepared from high and low strain mice and from 5-day-old and adult mice. Enzyme from high and low strains can be purified to the same specific activity and has indistinguishable electrophoretic and heat denaturation properties. This evidence supports the hypothesis that the high liver activity in C57BL/6 mice is due to the presence of more enzyme molecules/g of liver than is found in low activity mice. Using radiolabeling and specific immunoprecipitation of alcohol dehydrogenase, it has been established that high level mice (C57BL/6) have a 2-fold greater relative rate of synthesis of liver alcohol dehydrogenase than is found in low strain mice (C3H). Thus, the action of the Adh-1-t locus in the mouse is to control the level of alcohol dehydrogenase protein in the liver by controlling the rate of synthesis of this enzyme.

We previously described the isolation of the IC10 retrovirus which transduced the v-Rmil oncogene, a new member of the mil/raf gene family. This virus was generated during serial passaging of Rous-associated virus type 1 (RAV-1) in chicken embryo neuroretina (NR) cells and was selected for its ability to induce proliferation of these nondividing cells. IC10 was isolated after six passages of culture supernatants but was not detected in proliferating NR cells during early virus passages. In this study, we molecularly cloned and sequenced another v-Rmil-containing provirus, designated IC11, from NR cells infected at the third virus passage of the same experiment. Both IC11 and IC10 transduced only the serine/threonine kinase domain of c-Rmil. Comparison of v-Rmil and c-Rmil sequences indicated that amino-terminal truncation is sufficient to activate the mitogenic properties of c-Rmil. IC11 and IC10 have identical 3' ends but differ by their 5' RAV-1-Rmil junctions. The 3' ends of both viruses were generated by recombination between Rmil and env genes, involving partial sequence identity. The 5' RAV-1-Rmil junction of IC11 was formed by a splicing process between the RAV-1 leader and a 37-bp c-Rmil exon located upstream of the kinase domain. NR cells infected with this virus synthesize a unique Rmil protein. IC10 contains most of the gag gene recombined with v-Rmil and encodes a gag-Rmil hybrid protein. Serial passaging of IC11 in NR cells led to the formation of a gag-Rmil-containing retrovirus. These results indicate that IC11 represents an early step in transduction and that this virus further recombined with RAV-1 to generate IC10. They confirm our previously proposed model for the multistep generation of v-mil-transducing retroviruses. Therefore, activation and transduction of c-mil and c-Rmil, in NR cells infected with RAV-1, result from a common mechanism.

We previously reported that serial passaging of Rous-associated virus type 1 in nondividing chicken embryo neuroretina cells leads to reproducible generation of acutely mitogenic retroviruses that transduced the catalytic domain of c-mil/c-raf or c-Rmil/B-raf. On the basis of structural analysis of several retroviruses, we proposed that the early step of oncogene transduction is the constitution of alternatively spliced leader-delta onc-poly(A) transcripts. Here, we show that neuroretina cells do synthesize hybrid leader-delta mil and leader-delta Rmil RNAs and that these RNAs exhibit mitogenic properties and serve as templates for the generation of transducing retorviruses.

We have previously reported that a serine(threonine) protein kinase that phosphorylates histone H1 in vitro is activated by tyrosine phosphorylation in v-Src-transformed rat 3Y1 fibroblasts. We now refer to this kinase as YRP kinase, for tyrosine-regulated protein kinase. Since YRP kinase may play a role in mediating the growth-stimulatory and morphology-altering effects of v-Src, we have further examined the signal transduction involved in the activation of YRP kinase. Although YRP kinase is constitutively activated in fibroblasts transformed by v-Src, activation of protein kinase C was also found to lead to activation of YRP kinase. Activation of YRP kinase by protein kinase C was found to be potentiated by vanadate treatment or overexpression of c-Src. The activation of YRP kinase by v-Src, however, does not appear to be mediated by protein kinase C, suggesting that YRP kinase can be activated by two separate signal transduction pathways. Transformation of fibroblasts by v-Ras or v-Mil did not result in activation of YRP kinase, indicating that the MAP kinase pathway does not mediate the activation of YRP kinase by v-Src or protein kinase C.

Tissue-specific genetic variation in expression of the alcohol dehydrogenase, encoded by the Adh-1 gene, is found between C57BL/6J (B6) mice and B6.S congenic mice. B6.S mice contain a variant Adh-1 allele derived from a wild Danish strain in a B6 genetic background. B6 mice have nearly twice the alcohol dehydrogenase activity in liver but less than half the activity in kidney as B6.S mice. These tissue-specific genetic changes in alcohol dehydrogenase expression are manifest at the level of Adh-1-encoded mRNA. The regulatory site(s) involved act cis in both kidney and liver. These strains also differ in the extent to which androgen induces mRNA encoded by kidney Adh-1, with androgen increasing these levels 17-fold and 7.4-fold in the B6 and B6.S kidney, respectively. To identify the regulatory mechanism(s) underlying this strain variation in Adh-1 transcription in the B6 and B6.S kidney, liver, and androgen-induced kidney. For both uninduced and induced kidney, a difference in the transcription rate alone accounts for the strain difference in mRNA concentration. In contrast, because the Adh-1 transcription rate in liver does not differ significantly between B6 and B6.S mice, strain-specific variation in posttranscriptional regulation must be operative. Taken together these results indicate that the variation in Adh-1 expression between B6 and B6.S mice results from changes in both transcriptional and posttranscriptional control, and these controls are differentially operative in kidney and liver.

In a biosysteiriatic analysis of Cynodonover 700 interspecific and nearly 2,000 intervarietal hybrids were produced. C. barberi, C. arcuatus, and C. plectostachyusproved to be completely isolated from each other and the rest of the genus. C. aethiopicuscould be crossed with C. dactylonand C. nlemfuensis, but with great difficulty. Hybrids between the remainder of the taxa could be produced more easily and the chromosome behavior of these hybrids is reported. In all crosses between diploid taxa, the most common configuration is nine pairs. The most common configuration in triploid hybrids is nine pairs and nine univalents regardless of the parentage. Chromosome pairing in tetraploid hybrids is variable. There is little or no genome differentiation among the species that can be crossed. The evidence is discussed with respect to a recent revision of the genus.

Differential scanning calorimetry and thermogravimetric analysis curves were obtained for cotton cellulose in the presence of both flame-retarding and nonflame-retarding compounds and evaluated quantitatively for ΔH, activation energy, total weight loss, and char remaining after pyrolysis. Twenty-three compounds were tested and were found to fall roughly into three groups: (I) those which do not undergo decomposition in the temperature interval in which cellulose decomposes (200-400°C); (II) those which decompose appreciably during or preceding this temperature range; and (III) those which do not interact in any way with cellulose. It was found that, with increasing molar add-on, heat liberated from cellulose decreased for group I, increased for group II, and was not a function of molar add-on for III.A study of the kinetics of decomposition for these systems indicates that, while the majority of reactions proceeded as a pseudo first-order process, there are several exceptions to the trend. As would be expected for a first-order process, activation energy was found to decrease with increasing flame retardancy.Further, it has been observed that the addition to cellulose of any of the compounds from the first two groups lowers the onset temperature of decomposition and the temperature at which the first major weight loss begins. This temperature decrease approaches some type of limiting value for all the compounds, and varies from compound to compound. In addition, a large increase in remaining char results from a very small add-on, and this, too, tends to approach a limiting value as add-on increases.

The presence of a single plasmid 8.5 kb in size has been demonstrated in a cholesterol biotransforming strain of Micrococcus. A detailed physical map of the plasmid has been constructed using various restriction enzymes. Streptomycin resistance has been localized on a 1.8-kb fragment of pMQV10. Copyright 1993, 1999 Academic Press

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Without Abstract: