Rotation of melting ice disks due to melt fluid flow.

We report experiments concerning the melting of ice disks (85 mm in diameter and 14 mm in height) at the surface of a thermalized water bath. During the melting, the ice disks undergo translational and rotational motions. In particular, the disks rotate. The rotation speed has been found to increase with the bath temperature. We investigated the flow under the bottom face of the ice disks by a particle image velocimetry technique. We find that the flow goes downwards and also rotates horizontally, so that a vertical vortex is generated under the ice disk. The proposed mechanism is the following. In the vicinity of the bottom face of the disk, the water eventually reaches the temperature of 4 °C for which the water density is maximum. The 4 °C water sinks and generates a downwards plume. The observed vertical vorticity results from the flow in the plume. Finally, by viscous entrainment, the horizontal rotation of the flow induces the solid rotation of the ice block. This mechanism seems generic: any vertical flow that generates a vortex will induce the rotation of a floating object.

Surface tension profiles in vertical soap films.

Surface tension profiles in vertical soap films are experimentally investigated. Measurements are performed by introducing deformable elastic objets in the films. The shape adopted by those objects once set in the film is related to the surface tension value at a given vertical position by numerically solving the adapted elasticity equations. We show that the observed dependency of the surface tension versus the vertical position is predicted by simple modeling that takes into account the mechanical equilibrium of the films coupled to previous thickness measurements.

Single thermal plume in locally heated vertical soap films.

A vertical soap film is maintained by injection of a soap solution from the top. The film is then locally heated. Thermal plumes may be observed to rise in the film, depending on the magnitude of the heating and injected flows. The nearly two-dimensional nature of the system allows to visualize the motion of the plumes using an infrared camera. A model is proposed to describe the growth, emergence, and stationarity of the plumes in the film by taking into account both magnitudes of the heating ΔT and injected flow Q.

Effects of 8 weeks of vibration training at different frequencies (1 or 15 Hz) in senior sportsmen on torque and force development and of 1 year of training on muscle fibers.

OBJECTIVE: To examine the effects of 8 weeks of vibration training at different frequencies (1 and 15 Hz) on maximal isometric torque and force development in senior sportsmen, and of 1 year of heavy-resistance and vibration trainings on muscle fibers. METHODS: Seven healthy senior sportsmen (mean age: 69.0 +/- 5.4 years) performed an 8 weeks of strength training of knee extensors. Vibrations were applied vertically to the axis of movement during training. One leg of each subject was trained at a frequency of 1 Hz, while the other leg was trained at 15 Hz. Measures of isometric peak torque (at knee-angles of 60, 90 and 120 degrees ) and force development were recorded before and after training. Four sportsmen continued a year-long heavy-resistance training adding every second week a session of vibration training. After training, muscle biopsies were harvested from their quadriceps muscles and used for structural analyses. Morphometry of muscle fibers was performed by light microscopy. Immunohistochemistry using anti-MHCemb and anti-N-CAM antibodies was performed to measure potential muscle damage. Data from muscle morphometry were compared to that of a series of vastus lateralis biopsies harvested from 12 young sportsmen and four healthy elderly. RESULTS: Our results showed a significant increase in isometric peak torque at both 1 and 15 Hz vibration frequency in all three measured angles of the knee. There was no significant difference between the two frequencies, but we could find a higher increase in percentage of maximum power after the 1 Hz training. The results of force development showed a slight increase at the 1 Hz training in measured time frames from 0 to 50 and 200 ms, without statistical significance. A trend to significance was found at the 1 Hz training at the time window up to 200 ms. The 15 Hz training showed no significant changes of force development. Muscle biopsies show that the muscles of these well trained senior sportsmen contain muscle fibers which are 35% larger than those of sedentary elderly and, unexpectedly, 10% larger than those of young sportsmen. Despite 1 year of heavy resistance and vibration training, no evidence of muscle damage or denervation/reinnervation could be observed by light microscopy analyses, ATPase histochemistry and immunohistochemistry using anti-N-CAM or anti-MHC-emb antibodies. DISCUSSION: Integration of vibration to conventional strength training in elderly sportsmen induces similar improvement of isometric peak torque and force development independently from the vibration frequency after 8 weeks of training, and long-term results in the surprising evidence of hypertrophic muscle fibers larger than those of young active sportsmen. The observation that the vibration training with low frequency is safe opens the possibility to test these rehabilitation procedures in sedentary elderly.

Subclinical myopathy in patients affected with newly diagnosed colorectal cancer at clinical onset of disease: evidence from skeletal muscle biopsies.

OBJECTIVE: To evaluate skeletal muscle biopsy from asymptomatic patients affected with newly diagnosed colorectal cancer and to identify pathological features which may be indicative of tumor-associated muscle disorders, potentially leading to cachexia. METHODS: Patients affected with newly diagnosed colorectal cancer at clinical onset of disease underwent biopsy of the rectus abdominis muscle during elective laparoscopic tumor resection, before chemotherapeutic treatment. Morphometric analyses, ATPase histochemistry and immunohistochemical studies using antibodies directed to N-CAM and to MHC-emb, two sound makers of muscle denervation and injury-induced muscle regeneration, were performed on intraoperative muscle biopsies from ten patients. Muscle biopsies from rectus abdominis of seven subjects affected with non-neoplastic condition, which underwent laparoscopic surgery, were used as controls. RESULTS: In patients' biopsies, we observed a surprisingly high percentage of myofibers with internalized or central nuclei compared to controls (9.15 +/- 8.9 versus 0.6 +/- 0.9, p<0.0003). In addition, in the 30% of patients, small myofibers expressing the MHC-emb have been identified (0.4 +/- 0.5 positive fibers/mm(2)), while in 50% of patients, larger fibers positive for N-CAM have also been detected (0.7 +/- 1.1 positive fibers/mm(2)), suggesting that investigated muscle biopsies exhibit other evidence of muscle fiber injury/regeneration and/or denervation. Among the 10,000 analysed myofibers in control biopsies, no MHC-emb and N-CAM-positive muscle fibers have been detected. Thus, patients affected with newly diagnosed colorectal cancer at clinical onset of disease display early signs of a subclinical myopathy. DISCUSSION: Factors and mechanisms of this cancer-associated myopathy are yet unknown. The facts that the great majority of the abnormally nucleated myofibers are of the fast type and that regenerating myofibers are present, suggest a myogenic response to the colorectal cancer and not to the laparoscopic modalities of the biopsy harvesting. Follow-up of the patients will elucidate the clinical relevance of our observation, and further studies investigating the molecular mechanism underlying this early cancer-associated myopathy will hopefully provide some pathogenetic clues leading to the identification of potential specific targets for therapeutic intervention to prevent tumor cachexia.

Polymyositis, dermatomyositis and malignancy: a further intriguing link.

The association between malignancy and autoimmune myositis has been largely described and confirmed by numerous epidemiological studies. The temporal relationship between the two pathologic conditions can vary: malignancy may occur before, at the same time or following the diagnosis of myositis. Beside these observations, the molecular mechanisms underlying this association are still unknown, even though it has been demonstrated a possible antigenic similarity between regenerating myoblasts and some cancer cell populations. To better identify peculiar histopathologic features common to cancer and myositis, we screened muscle biopsies from patients affected with polymyositis, dermatomyositis, myositis in association to cancer, and from patients affected with newly diagnosed cancer, but without myositis. Similarly to the histopatologic features that were observed in the muscle from myositis patients, especially in those with cancer associated myositis, in patients affected with malignancy at the clinical onset of disease we observed early sign of myopathy, characterized by internally nucleated and regenerating myofibers, most of them expressing the neural cell adhesion molecule. The hypothesis that in a particular subset of individuals genetically predisposed to autoimmunity, an initial subclinical tumor-induced myopathy may result in an autoimmune myositis, represents a further intriguing link behind the association of these two conditions.

[Nature and classification of nursing interventions in an adult outpatient clinic for chemotherapy]. / Natureza e classificação das intervenções de enferma gem em ambulatório de quimioterapia de adultos.

The purpose of the present descriptive study was to identify, through a retrospective analysis of records, the nature of nursing interventions as well as to establish the relationship between the nature of these interventions and the problems found. The sample was formed by 184 records of patients in their first nursing consultation at the Adult Chemotherapy Outpatient Unit of Hospital São Paulo from January to June, 1997; 37 records were selected at random: 19 male and 18 female patients. Results showed the predominance of interventions centered in patients' psychobiological needs. Educative interventions were more frequently performed when related to patients psychosocial needs. The correspondence between the identified problems and proposed interventions was evidenced when the psychobiological needs were met.

[Production of scientific papers by nurses from public and private hospitals in the district of Sao Paulo]. / Produção científica publicada pelas enfermeiras de hospitais públicos e privados do município de São Paulo.

This study shows the nurse's scientific publication from seven public and six private hospitals in São Paulo city, from january/1989 to june/1995. From a total of 486 papers identified, 242 were published as abstracts, 124 in annals, 92 in nationals and international journals, 21 as book chapters and 7 as books in nursing. The facilities and difficulties in publishing nursing scientific production were also discussed.

[Nursing process and structure for cancer patients]. / Estrutura e processo assistencial de enfermagem ao paciente com câncer.

This study aimed at evaluating the structure for cancer patient assistance and antineoplasic chemotherapy assistance process. It has been performed at six internation units and one out-patient unit at a university hospital. Systematized observation and semistructured interview were used from January to June, 1996. It was noticed the there were some deficiencies in the physical area and installations of the studied units. Generally, nursing team had no formal training in Oncology, except for Chemotherapy Sector. The absence of a systematized nursing assistance and differences among the studied units as for technical organizational aspects for antineoplasic administration as well as patients and staff interaction has been observed. Inadequations observed could be minimized with such a politics which would be able to increase public sector financing, planting of systematized care and inclusion of Oncology in the permanent nursing team education.

Sequence of a new HLA-DR4 allele with an unusual residue at position 88 that does not seem to affect T-cell allo recognition.

New HLA alleles can be identified by unorthodox patterns observed during low-resolution typing performed with sequence specific oligonucleotide probes (SSOP). One of the best examples is locus DRB1, where allelic subtypes are characterized by a combination of a limited number of residues located in three hypervariable regions of exon 2. HLA-DR oligotyping analysis of a female caucasoid bone marrow donor led to the identification of an individual that typed as DRB1*11, DRB3*02, DRB4*01, DQB1*0301-0302. This donor was, however, typed by serology as DR11 DR4, DR52, DR53, DQ7 DQ8. PCR-SSP typing for DR4 subtype revealed an amplification pattern typical for DRB1*0404. After sequencing the entire exon 2, a new DRB1 allele was identified: DRB1*04var that is identical to DRB1*0404, except for one nucleotide at codon 88 resulting in a Ser-->Arg exchange. This mutation had prevented amplification with the DR generic primers. Cellular typing by three HTCs-DRB1*0404/DW14 from the 9th Workshop showed that this DRB1*04var typed exactly like a DW14 cell. This suggests that residue 88 does not affect T cell recognition.

[The situation of nursing research in Sao Paulo municipal hospitals]. / Situação da pesquisa em enfermagem em hospitais do município de São Paulo.

The objective of this study is to show nursing research situation in public and private hospitals in the city of São Paulo, from 1989 to 1993. It is an exploratory and descriptive research. The questionnaire was answered by nursing directors of 14 hospitals--7 public and 7 private. 114 researches were developed in public hospitals and 40 in private hospitals. The results demonstrated that the majority of studies were developed by four or more authors and most of them were presented in scientifics events. The facilities and difficulties to develop research and to implement the results in nursing practice were also pointed out. Research centers, faculty-practice nursing, and admission of nurses researched were registered as strategies to develop research in some of these institutions.

A new class of ligand-gated ion channel defined by P2x receptor for extracellular ATP.

Extracellular ATP exerts its effects through P2 purinoceptors: these are ligand-gated ion channels (P2x) or G-protein-coupled receptors (P2Y, P2U). ATP at P2x receptors mediates synaptic transmission between neurons and from neurons to smooth muscle, being responsible, for example, for sympathetic vasoconstriction in small arteries and arterioles. We have now cloned a complementary DNA encoding the P2x receptor from rat vas deferens and expressed it in Xenopus oocytes and mammalian cells. ATP activates a cation-selective ion channel with relatively high calcium permeability. Structural predictions suggest that the protein (399 amino acids long) is mostly extracellular and contains only two transmembrane domains plus a pore-forming motif which resembles that of potassium channels. The P2x receptor thus defines a new family of ligand-gated ion channels.

High-level expression of the human neurokinin-1 receptor in mammalian cell lines using the Semliki Forest virus expression system.

Human neurokinin-1 receptor cDNA was introduced into the pSFV1 Semliki Forest virus (SFV) vector and the in vitro transcribed RNA was electroporated into BHK cells with pSFV-Helper RNA. This procedure resulted in the packaging of a high-titer SFV-NK-1 virus stock containing approximately 5 x 10(9) infective units/ml. Infection of baby hamster kidney, COS-7, Chinese hamster ovary and human osteosarcoma cells yielded high levels of human neurokinin-1 receptor expression as assessed by [3H]substance P binding. The maximal receptor expression level obtained was 4 x 10(6) receptors/cell and studies of the post-infection time indicated that a high level of receptor expression was observed 10-24 h post-infection. The human neurokinin-1 receptor expressed in infected baby hamster kidney, COS-7 and Chinese hamster ovary cells was able to stimulate Ca2+ mobilization indicating functional coupling to guanine-nucleotide-binding proteins. The application of the Semliki Forest virus expression system will permit the rapid and efficient production of large quantities of receptor protein for both pharmacological and structural studies.

[The access, utilization and acceptance of dermatology services at a teaching health center from the viewpoint of Hansen's disease patients]. / Acesso, utilização e aceitação dos serviços de dermatologia de um centro de saúde escola sob o modo de ver dos hansenianos.

The present Case Study intends to analyse the access, utilization and acceptance of the Dermatology services of a SHC based mainly in the orally reported histories of 27 patients affected by Hansen's disease. The access to SHC--concerning its organization--took place without difficulty, except for the attendance services. However, the utilization level of the services was found to be higher than the established pattern of the care provided whether in actual episodes of the disease or not. The acceptance of the services rendered was consensual and both the technical quality and interpersonal relationship were emphasized.

Molecular characterisation, expression and localisation of human neurokinin-3 receptor.

The complete amino acid sequence of the human neurokinin-3 receptor was deduced by DNA sequence analysis of human genomic fragments. Comparison of the predicted primary structure with those for the human neurokinin receptors 1 and 2 shows a highly conserved pattern of seven hydrophobic regions with maximum divergence occurring at the amino- and carboxy-termini. The position of intron-exon junctions are identical to those in other reported neurokinin genes. Using a chimeric genomic-cDNA gene, the human NK-3 receptor was expressed in Xenopus laevis oocytes where it mediates membrane conductance changes in response to its agonist, neurokinin B. More significantly, expression of the gene in mammalian cells resulted in detection of receptor binding as well as neurokinin-stimulated calcium mobilization and arachidonic acid release, all displaying the pharmacological characteristics expected of a neurokinin-3 receptor. By using the polymerase chain reaction we have shown that mRNA for the human neurokinin-3 receptor is expressed predominantly in the central nervous system.

Human immunodeficiency virus DNA amplification and serology in blood donors.

The significance of indeterminate screening antibody test for human immunodeficiency virus (HIV) serology is still difficult to evaluate, especially in low-risk populations. One hundred twenty-seven blood donors with an initially reactive screening test for HIV antibodies were enrolled in this study. The sera of 95 of these blood donors were reactive on repetition of the test, and none had detectable circulating p24 antigen. Western blot (WB) analysis of the repeatedly reactive sera was as follows: 9 positive, 31 indeterminate, and 55 negative. One of the blood donors with indeterminate WB later presented a seroconversion. On subsequent control 3 to 12 months later, the sera from donors with indeterminate or negative WB did not present any parameters that may indicate a seroconversion. DNA was purified from citrated blood collected from the 127 blood donors at the time of the initial antibody screening. Five micrograms of each DNA sample corresponding to 7 x 10(5) nucleated white blood cells was amplified by polymerase chain reaction (PCR) in the presence of oligonucleotides (primers) corresponding to a highly conserved segment of the pol gene. The detection of amplified DNA was achieved by dot blot and Southern blot using appropriate 32P-labeled oligonucleotides. Ten DNA samples were positive, 9 corresponded to blood donors with a positive HIV serology, and 1 to the blood donor who later presented a seroconversion. These results confirm the sensitivity of the PCR for the diagnosis of HIV infection; they also suggest that repetition of the serology at 3- to 12-month intervals is a valuable procedure for the control of HIV infection status in blood donors.