Regulation of carnitine palmitoyltransferase activity in the liver and brown adipose tissue in the newborn rat: effect of starvation and hypothermia

The overt activity of hepatic carnitine palmitoyltransferase (CPT1) increased during the last day of gestation in the foetus and after prolonged starvation in the newborn kept at 37 degrees C. Its sensitivity to inhibition by malonyl-CoA decreased during the perinatal period studied. Brown fat CPT1 increased under the same experimental conditions. However, its sensitivity to malonyl-CoA remains unchanged. Hypothermia at 24 degrees C decreased in the liver and increased in brown adipose tissue CPT1 activity in response to fasting. Glucose injection at birth decreased CPT1 activity in the liver but did not have any effect in the presence of mannoheptulose. This effect of glucose was non-significant in brown adipose tissue.     

Control of the annual testicular cycle of the marbled-newt by p53, p21, and Rb gene products

p53, p21, and Rb are proteins with an important role in cell-cycle control. The expression and distribution of these gene products and the apoptotic rate were studied in the marbled-newt testis along the annual cycle to know the role of these factors in the control of spermatogenesis and glandular tissue formation. The study was carried out using Western blot analysis and immunohistochemistry. The results differed from those, previously reported in mammals showing constant spermatogenesis. Greater expression of p53 and p21 was found in the quiescence period and was detected in PCGs (primordial germ cells), spermatogonia, follicular, interstitial cells, and glandular tissue. Greater expression of Rb and phosph-Rb was present in the proliferation period, in PCGs, and spermatogonia. Apoptosis was only detected in secondary spermatogonia (quiescence and spermiogenesis periods) and primary spermatocytes (proliferation and spermiogenesis periods). In the quiescence period, the increase in p53 expression activates p21 expression, which inhibits Rb phosphorylation and arrests the cell cycle in G1. In the proliferation period and, in a lesser degree, in the spermiogenesis period, the expressions of p53 and p21 decrease and phosph-Rb increases, enhancing cell proliferation. These gene products do not seem to be related to apoptosis.     

Insertion of a 27 amino acid viral peptide in different zones of Escherichia coliβ-galactosidase: Effects on the enzyme activity

Abstract Seven internal, putatively exposed regions of Escherichia coli β-galactosidase have been explored regarding their tolerance to insertions of large foreign peptides. Small sequence modifications, including amino acid substitutions and small deletions, were introduced into the lacZ gene to generate unique Bam HI restriction sites. By using these mutant genes, a 27 amino acid stretch reproducing the hypervariable loop of foot-and-mouth disease virus VP1 protein (site A) was further inserted in predefined regions of the enzyme. Among the 13 resulting engineered proteins only three, carrying sequence modifications within a short region, are active, with only moderate reduction of their specific activities. The identified permissive region, which involves amino acids 275 to 279, seems to be a flexible area that could be appropriate incorporate and study biological properties of heterologous peptides in correctly folded β-galactosidase chimeric proteins.     

A Feulgen microspectrophotometric study of the DNA content of essential fatty acid-deficient rat pancreas treated with nitrosomethylurea

Microspectrophotometric DNA measurements in exocrine pancreas of essential fatty acid-deficient (EFAD) and EFA-sufficient (EFAS) rats which received a single intraperitoneal injection of the carcinogen nitrosomethylurea (NMU) or saline (SAL) was the subject of the present report. The DNA content of acinar pancreatic cells of SAL-injected EFAD and EFAS rats was diploid. NMU-induced pancreatic focal acinar cell hyperplasia (FACH) had one main cell population with a diploid content, whereas in the intervening parenchyma there were diploid and tetraploid cells. The number of tetraploid cells was smaller in EFAD rat pancreas than in EFAS indicating a diet dependent effect. NMU-induced FACH had a diploid distribution pattern indicating that cells are in a G1, quiescent phase, contrasting with AZA-induced similar lesions which showed an abnormal ploidy. It remains to be established whether DNA phenotypic traits of NMU and AZA induced FACH reflect the neoplastic potentials of both types of lesions. The decreased number of tetraploid cells in EFAD rat pancreas is in keeping with data indicating a promoting effect of the EFA linoleic and arachidonic acids on growth rate of certain cell populations in vitro.     

Differentiated biological activity of Vero cytotoxins (VT) released by human and porcine Escherichia coli strains

Abstract We have investigated the biological activity in the filtered culture supernatants from 9 VT-producing Escherichia coli strains. The filtrates from 4 strains (3 of human and one of bovine origin), were cytotoxic on Vero and HeLa cells, and caused death in intraperitoneally injected adult mice. The 5 strains of porcine origin showed cytotoxic activity on Vero and Y-1 cells but not on HeLa cells. Filtrates of these latter strains were not lethal for adult mice. VT-cytotoxins produced by all strains were inactive in the infant mouse test and the filtrates from 7 of 8 VT-producing strains assayed in rabbit ileal loops caused fluid accumulation in at least one of the 3 rabbits employed.     

Winona H. Welch Herbarium of Hookeriaceae

In 1987, the DePauw University Herbarium (DPU) was transferred to the New York Botanical Garden (NY). Included was Winona Welch's research herbarium of Hookeriaceae, which consists of 306 types and 2586 non-type specimens. Separate lists of type specimens and collectors of non-type specimens are presented.     

Cystic Echinococcosis in the Province of álava,North Spain: The Monetary Burden of a Disease No Longer under Surveillance

Cystic echinococcosis (CE) is endemic in Spain but has been considered non-endemic in the province of Álava, Northern Spain, since 1997. However, Álava is surrounded by autonomous regions with some of the highest CE prevalence proportions in the nation, casting doubts about the current classification. The purpose of this study is to estimate the frequency of CE in humans and animals and to use this data to determine the societal cost incurred due to CE in the Álava population in 2005. We have identified epidemiological and clinical data from surveillance and hospital records, prevalence data in intermediate (sheep and cattle) host species from abattoir records, and economical data from national and regional official institutions. Direct costs (diagnosis, treatment, medical care in humans and condemnation of offal in livestock species) and indirect costs (productivity losses in humans and reduction in growth, fecundity and milk production in livestock) were modelled using the Latin hypercube method under five different scenarios reflecting different assumptions regarding the prevalence of asymptomatic cases and associated productivity losses in humans. A total of 13 human CE cases were reported in 2005. The median total cost (95% credible interval) of CE in humans and animals in Álava in 2005 was estimated to range between €61,864 (95%CI%: €47,304–€76,590) and €360,466 (95%CI: €76,424–€752,469), with human-associated losses ranging from 57% to 93% of the total losses, depending on the scenario used. Our data provide evidence that CE is still very well present in Álava and incurs important cost to the province every year. We expect this information to prove valuable for public health agencies and policy-makers, as it seems advisable to reinstate appropriate surveillance and monitoring systems and to implement effective control measures that avoid the spread and recrudescence of the disease.     

Isolation, purification and characterization of spleen ferritin of Gallus domesticus L

The ferritin from the spleen of the chickens has been isolated by a method of salt fractionation and by a pH change followed by purification in sephadex G-200. 2. The identification of the protein was carried out by acrylamide gel electrophoresis showing a single band. 3. The characterization of ferritin has been made by determination of molecular weight, amino acids analysis and the number of iron atoms (4520) which bound the ferritin. 4. The ferritin from the spleen of chicken is compared with the ferritin from the liver of pigeon.     

Interactions Crucial for Three-Dimensional Domain Swapping in the HP-RNase Variant PM8

The structural determinants that are responsible for the formation of higher order associations of folded proteins remain unknown. We have investigated the role on the dimerization process of different residues of a domain-swapped dimer human pancreatic ribonuclease variant. This variant is a good model to study the dimerization and swapping processes because dimer and monomer forms interconvert, are easily isolated, and only one dimeric species is produced. Thus, simple models for the swapping process can be proposed. The dimerization (dissociation constant) and swapping propensity have been studied using different variants with changes in residues that belong to different putative molecular determinants of dimerization. Using NMR spectroscopy, we show that these mutations do not substantially alter the overall conformation and flexibility, but affect the residue level stability. Overall, the most critical residues for the swapping process are those of one subunit that interact with the hinge loop of another one-subunit residue, stabilizing it in a conformation that favors the interchange. Tyr²⁵, Gln¹⁰¹, and Pro¹⁹, with Asn¹⁷, Ser²¹, and Ser²³, are found to be the most significant; notably, Glu¹⁰³ and Arg¹⁰⁴, which were postulated to form salt bridges that would stabilize the dimer, are not critical for dimerization.