Rheological studies with spherically shaped thin liquid films

The present work shows the first experimental and theoretical results for investigations on the rheology of liquid films. The experiments are planned to be performed under microgravity conditions. This environment will allow forming films of different thickness, which is impossible under ground conditions due to drainage. Then the films are forced to harmonic oscillations of the film area so that the film elasticity can be measured as a function of frequency. The presented theoretical model demonstrates the main relationships to be solved under corresponding boundary conditions     

Polo-like kinase 1 as a target for human cytomegalovirus pp65 lower matrix protein

Human cytomegalovirus (HCMV) pp65 protein is the major constituent of viral dense bodies but is dispensable for viral growth in vitro. pp65 copurifies with a S/T kinase activity and has been implicated in phosphorylation of HCMV IE1 immediate-early protein and its escape from major histocompatibility complex 1 presentation. Furthermore, the presence of pp65 correlates with a virion-associated kinase activity. To clarify the role of pp65, yeast two-hybrid system (THS) screening was performed to identify pp65 cellular partners. A total of 18 out of 48 yeast clones harboring cDNAs for putative pp65 binding proteins encoded the Polo-like kinase 1 (Plk1) C-terminal domain. Plk1 behaved as a bona fide pp65 partner in THS control crosses, and the interaction was confirmed by in vitro binding experiments. Endogenous Plk1 was coimmunoprecipitated with pp65 from transiently transfected COS7 cells. In infected fibroblasts, Plk1 was coimmunoprecipitated with pp65 at late infection stages. Furthermore, Plk1 was detected within wild-type HCMV particles but not within the particles of a pp65-negative mutant (RVAd65). The hydrophilic region of pp65 was phosphorylated in vitro by Plk1. These results suggest that one function of pp65 may be to capture a cell kinase, perhaps in order to alter its activity, nucleotide preference, substrate specificity, or subcellular localization to the advantage of HCMV.     

Dynamics and characterization of yeasts during ripening of typical Italian dry-cured ham

The evolution of the yeast population during manufacturing and ripening of dry-cured Parma ham was investigated. Contamination levels ranged from 10(5) to 10(7) cfu/g on muscle surface, 10(4) to 10(6) cfu/g on covering fat and exceeded 10(7) cfu/g on spreadable fat mince ("sugna"). Two hundred and sixty one yeast isolates underwent identification test, showing that the predominant species of yeast population during the whole maturing process were Debaryomyces hansenii, Candida zeylanoides, Debaryomyces maramus, and to a lesser extent, Candida famata and Hyphopichia burtonii. The species Candida catenulata, Candida guilliermondii, Candida edax and other genera like Cryptococcus and Wingea were occasionally found. The yeast counts and species distribution changed according to the stage of processing and to the ham sampling location. At the end of the cold phase, the washing procedure was effective in lowering the yeast count in muscle and fat surface layers, but during the next ageing stages, yeast colonization of unskinned ham muscle increased again, though species distribution changed if compared to previous manufacturing phases. The ripening steps taken into account from the end of the cold phase to the final outcome, were always characterized by more than one yeast species, suggesting that yeasts other than Debaryomyces spp. could play a remarkable role on the sensory and safety properties of typical Italian dry-cured ham.     

Prognostic impact of amenorrhoea after adjuvant chemotherapy in premenopausal breast cancer patients with axillary node involvement: results of the International Breast Cancer Study Group (IBCSG) Trial VI

Adjuvant chemotherapy-induced amenorrhoea has been shown to be associated with reduced relapses and improved survival for premenopausal breast cancer patients. Amenorrhoea was, therefore, studied to define features of chemotherapy (i.e. duration and timing) and disease-related factors which are associated with its treatment effects. We reviewed data from IBCSG Trial VI, in which accrual was between July 1986 and April 1993. 1196 of the 1475 eligible patients (81%) were evaluable for this analysis. The median follow-up was 60 months. Women who experienced amenorrhoea had a significantly better disease-free survival (DFS) than those who did not (P = 0.0004), although the magnitude of the effect was reduced when adjusted for other prognostic factors (P = 0.09). The largest treatment effect associated with amenorrhoea was seen in patients assigned to receive only three initial CMF courses (5-yr DFS: 67% versus 49%, no amenorrhoea; hazard ratio, 0.55; 95% confidence interval, 0.38 to 0.81; P = 0.002). DFS differences between amenorrhoea categories were larger for patients with ER/PR positive tumours (hazard ratio, 0.65; 95% confidence interval, 0.53 to 0.80; P = 0.0001). Furthermore, patients whose menses returned after brief amenorrhoea had a DFS similar to those whose menses ceased and did not recover (hazard ratio, 1.10; 95% confidence interval, 0.75 to 1.62; P = 0.63). The effects associated with a permanent or temporary chemotherapy-induced amenorrhoea are especially significant for node-positive breast cancer patients who receive a suboptimal duration of CMF chemotherapy. Cessation of menses, even for a limited time period after diagnosis of breast cancer, might be beneficial and should be prospectively investigated, especially in patients with oestrogen receptor-positive primaries.     

Ganciclovir resistance as a result of oral ganciclovir in a heart transplant recipient with multiple human cytomegalovirus strains in blood

The etiologic spectrum of acute encephalitis syndrome (AES) has not been well defined in Vietnam. Cohort and case-control studies were performed on all adult and pediatric AES patients admitted to the Neurology Service of Bach Mai Hospital between June 5 and August 3, 1995. Among pediatric AES patients, 31 (67%) of 46 had acute Japanese encephalitis (JE), compared with only two (6%) of 33 adult AES patients (P < 0.0001). For confirmed JE cases, serum specimens obtained 15-21 days after symptom onset had the highest mean anti-JE IgM signal-to-noise (P/N) ratios (8.08 + 1.09 SE). A serosurvey of adult household members did not reveal any cases of recent subclinical JE infection, although 26% had evidence of past JE infection. The use of bed netting was nearly universal but did not appear to reduce the risk of AES or JE. Given the high incidence of JE, particularly among children, Vietnam seems well suited for the development of a targeted JE vaccination strategy.     

Effect of hypothyroidism on hormone profiles in virgin,pregnant and lactating rats,and on lactation

Thyroid dysfunctions can produce reproductive problems. Untreated maternal hypothyroidism has serious consequences on development of offspring, resulting in stunted growth and mental retardation. The effects of propylthiouracyl-induced hypothyroidism (0.1 g l(-1) in drinking water starting 8 days before mating, or given to virgin rats for 30 or 50 days) on the serum profiles of hormones related to reproduction and mammary function (prolactin, growth hormone (GH), progesterone, corticosterone, oestradiol, insulin-like growth factor I (IGF-I), thyroid-stimulating hormone (TSH), triiodothyronine and tetraiodothyronine), and on mammary function in virgin, pregnant and lactating rats, were investigated. Propylthiouracyl treatment severely decreased circulating triiodothyronine and tetraiodothyronine concentrations, and increased serum TSH concentrations. Virgin rats showed prolonged periods of vaginal dioestrus, increased circulating progesterone concentrations and afternoon peaks of prolactin concentration, which are indicative of prolactin-induced pseudopregnancy. Propylthiouracyl-treated virgin rats had mammary development comparable to that of midpregnancy, and half of these rats had increased mammary casein and lactose concentrations. Serum prolactin concentrations were decreased on the afternoon of day 5 of pregnancy, increased during late pregnancy (days 15-21) and were normal during lactation. Circulating GH concentrations decreased on days 15-21 of pregnancy, whereas progesterone concentrations increased during late pregnancy and early lactation. Circulating oestradiol (measured in late pregnancy and in virgin rats), IGF-I and corticosterone concentrations were decreased. Although assessment of mammary histology showed no differences in extent of development, casein content was increased in propylthiouracyl-treated rats on day 21 of pregnancy; litter growth was severely reduced and at day 20 of age the pups were hypothyroid, with decreased GH serum concentrations. An acute suckling experiment was performed on days 10-12 of lactation to determine whether some impairment in mammary function or the suckling reflex might account for these differences. After an 8 h separation of mothers from their litters and 30 min of suckling, circulating prolactin values were not affected by propylthiouracyl treatment, but serum oxytocin concentration and milk excretion were reduced. In conclusion, hypothyroidism induces various alterations in the hormone profiles of virgin and pregnant rats, and induces pseudopregnancies and mammary development in virgin rats. These alterations do not appear to have an overt impact on the outcome of pregnancy and on mammary function during lactation, with the exception of the milk ejection reflex, which may account at least partially for the reduced litter growth.     

Endothelial Colony-Forming Cells Dysfunctions Are Associated with Arterial Hypertension in a Rat Model of Intrauterine Growth Restriction

Infants born after intrauterine growth restriction (IUGR) are at risk of developing arterial hypertension at adulthood. The endothelium plays a major role in the pathogenesis of hypertension. Endothelial colony-forming cells (ECFCs), critical circulating components of the endothelium, are involved in vasculo-and angiogenesis and in endothelium repair. We previously described impaired functionality of ECFCs in cord blood of low-birth-weight newborns. However, whether early ECFC alterations persist thereafter and could be associated with hypertension in individuals born after IUGR remains unknown. A rat model of IUGR was induced by a maternal low-protein diet during gestation versus a control (CTRL) diet. In six-month-old offspring, only IUGR males have increased systolic blood pressure (tail-cuff plethysmography) and microvascular rarefaction (immunofluorescence). ECFCs isolated from bone marrow of IUGR versus CTRL males displayed a decreased proportion of CD31+ versus CD146+ staining on CD45− cells, CD34 expression (flow cytometry, immunofluorescence), reduced proliferation (BrdU incorporation), and an impaired capacity to form capillary-like structures (Matrigel test), associated with an impaired angiogenic profile (immunofluorescence). These dysfunctions were associated with oxidative stress (increased superoxide anion levels (fluorescent dye), decreased superoxide dismutase protein expression, increased DNA damage (immunofluorescence), and stress-induced premature senescence (SIPS; increased beta-galactosidase activity, increased p16^INK4a, and decreased sirtuin-1 protein expression). This study demonstrated an impaired functionality of ECFCs at adulthood associated with arterial hypertension in individuals born after IUGR.     

Myoelectric activation pattern during gait in total knee replacement: relationship with kinematics, kinetics, and clinical outcome.

Gait usually presents an excellent improvement after total knee replacement. Nevertheless, some abnormalities persist even after a long period of time. The abnormal knee patterns have been attributed to several possible causes, such as implant geometry and surgical technique, posterior cruciate ligament sparing/sacrificing, preoperative "stiff-knee" pattern due to pain and altered biomechanics, weakness of the extensor muscles, preoperative arthritic pattern, proprioceptive deficiency, and multijoint degenerative involvement. Cocontraction of the knee flexors and extensors is a common strategy adopted to reduce strain and shear forces at the joint, but it increases compressive forces and joint loading. Even in patients with an excellent functional score, the duration of the implant may be compromised by an altered neuromuscular control of the knee. In this paper, we report a single case study carried out over two years on a patient that underwent total knee replacement. The aim of this work is to show that quantitative gait analysis is essential to augment the understanding of the mechanisms underlying gait, thus enabling clinicians to adapt the rehabilitation program to the specific patient. Although the limits of single case reports are obvious, we believe that this evaluation methodology could be beneficial for assessing the effectiveness of rehabilitation programs aimed at achieving an active control of the knee during gait through a correct muscular activation pattern.     

Substructuring Preconditioners for Mortar Discretization of a Degenerate Evolution Problem

In this paper we present new efficient variants of substructuring preconditioners for algebraic linear systems arising from the mortar discretization of a degenerate parabolic system of equations. The new approaches extend and adapt the idea of substructuring preconditioners to the discretization of a degenerate problem in electrocardiology. A polylogarithmic bound for the condition number of the preconditioned matrix is proved and validated by numerical experiments.     

Hard turning of an alloy steel on a machine tool with a polymer concrete bed

Finish turning of 39NiCrMo3 alloy steel in the hardened state has been widely investigated under dry, minimum quantity of lubricant and wet cutting conditions, using inserts in ceramic and PCBN materials, on turning centers equipped with polymer concrete and cast iron beds. The progress of workpart surface roughness and tool wear with cutting time has been measured and the results analysed and discussed in detail. It has been observed that dry cutting leads to the lowest values of tool wear and surface roughness, whilst the minimal quantity of lubricant technique does not provide advantages regarding to dry turning. Furthermore, the PCBN inserts are characterised by a longer tool life than the one exhibited by the ceramic inserts. Finally, the outstanding damping and high rigidity of the polymer concrete bed has a beneficial effect on both tool wear and workpiece surface finish.