Ti-Ag-Pd alloy with good mechanical properties and high potential for biological applications.

Ti-based alloys containing Ag were produced by tilt-casting method and their properties were studied. Even in its as-cast state, Ti94Ag3Pd3 showed relatively high tensile properties, good electrochemical behavior, and good biocompatibility. The relatively good mechanical properties of the as-cast α-Ti-type Ti94Ag3Pd3 alloy (tensile strength up to 850 MPa and elongation of ~10%) can be explained by its severely deformed, fine crystalline structure. The high biocompatibility of Ti94Ag3Pd3 can be explained by the Ag-Pd interaction, which inhibits the release of Ag ions from the surface. Ag, in combination with Pd has no toxic effects and demonstrates useful antimicrobial properties. The Ti94Ag3Pd3 alloy shows a good potential to be applied as a biomedical implant alloy.

[Age changes of immunological, morphological and biochemical indices of male reproductive system].

The article analyzes the dependence of bactericidal activity of sperm--natural resistance factors controlling the survival of bacteria in the urogenital tract, on the age of men. These data are compared with the results of the standard (on the recommendations of the WHO) spermogram, reflecting reproductive health. Due to the fact that one of the main etiological agents of infectious disease groups in the male reproductive system in adulthood are Staphylococcus spp., we consider the level of bactericidal activity of sperm in resident and transient carriage of S. aureus and S. epidermidis.

Management and results of treatment of breast cancer patients having sentinel lymph node micrometastases.

According to current therapeutic guidelines, finding micrometastases in the sentinel node (SLN) of a patient with non-advanced breast cancer is not an absolute indication for adjuvant axillary lymph node dissection (ALND). This work presents our experiences regarding this clinical problem. 1071 breast cancer patients were referred for sentinel node biopsy between January 2004 and December 2011. Metastases were found in 245 of the removed lymph nodes. In 49 patients lymph node changes turned out to be micrometastases or isolated tumor cells (ITC). ALND was performed in 38 cases of sentinel node micrometastases or ICTs. In three patients involvement of other axillary lymph nodes was found in the studied tissue material (7.9% vs. 37.9% for metastases >2mm). The remaining patients with micrometastases in the SLN (11/49) were treated conservatively. No local axillary recurrences or neoplastic metastases were found in this group of patients with SLN micrometastases. Mean follow-up period in patients who had undergone ALND was 18.0 months (4 to 60 months) and 21.4 months (9-40 months) in patients without ALND. Non-radical surgical treatment in the presence of SLN micrometastases in patients with non-advanced breast cancer does not lead to therapeutic failure (local axillary recurrences, distant metastases). Obtaining favorable outcomes of conservative treatment in the analyzed group of patients does not require additional modification of the adjuvant therapy.

[Dynamics of circulating immune complexes and immunoglobulins in response to polytrauma in experiment].

In experimental polytrauma conditions in the blood serum the immune complexes are accumulating. The dynamics of their contents is a wave-like, the periods of increase are determined--in 3 and 21 days and reduction--in 7-14 and 28 days. Accordingly, the IgA and IgG contents are changing with characteristic significant reduction in 14 days of posttraumatic period. The IgM content reaches maximum in 1-3 days with further reduction lower than norm till the end of experiment.

[The impact of polytrauma on dynamics of late apoptosis in the tissue lymphocytes].

The changes in the late apoptosis intensity in lymphocytes, obtained from various organs under polytrauma impact, were studied in experiment. In laboratory animals of a control group the late apoptosis intensity appeared essentially bigger in pulmonary lymphocytes, comparing with those from the heart and the liver. Nonsignificant changes of intensity prolong 2 h - 3 days with essential increase in 7 days, decrease--on the 14-21th days and repeated increase--on the 28th day were characteristic in the polytrauma dynamics for late apoptosis in the lymphocytes, obtained from the lungs, the heart and the liver. It is more characteristic for pulmonary lymphocytes, significantly less--for those from the heart and even lesser--from the liver.

Use of tunable nanopore blockade rates to investigate colloidal dispersions.

Tunable nanopores fabricated in elastomeric membranes have been used to study the dependence of ionic current blockade rate on the concentration and electrophoretic mobility of particles in aqueous suspensions. A range of nanoparticle sizes, materials and surface functionalities has been tested. Using pressure-driven flow through a pore, the blockade rate for 100 nm carboxylated polystyrene particles was found to be linearly proportional to both transmembrane pressure (between 0 and 1.8 kPa) and particle concentration (between 7 × 10(8) and 4.5 × 10(10) ml( - 1)). This result can be accurately modelled using Nernst-Planck transport theory, enabling measurement of particle concentrations. Using only an applied potential across a pore, the blockade rates for carboxylic acid and amine coated 500 and 200 nm silica particles were found to correspond to changes in their mobility as a function of the solution pH. Scanning electron microscopy and confocal microscopy have been used to visualize changes in the tunable nanopore geometry in three dimensions as a function of applied mechanical strain. The pores were conical in shape, and changes in pore size were consistent with ionic current measurements. A zone of inelastic deformation adjacent to the pore has been identified as important in the tuning process.

[Resuscitation of a patient with deep hypothermia using extracorporeal circulation]. / Resuscitace hluboce podchlazeného nemocného s pouzitím mimotelního obehu.

The case-history describes successful resuscitation of a young man who was found after 15 hours following attempted suicide (intoxication with carbamazepine) in deep hypothermia (19 degrees C) with cardiac arrest. For rewarming the patient extracorporeal circulation was used. The patient was successfully disconnected from the extracorporeal circulation, relieved of the shock incl. severe rhabdomyolysis and intoxication with carbamazepine and discharged to domiciliary treatment without suffering from a neurological deficiency.

Effect of repeated closures on opening torque values in seven abutment-implant systems.

STATEMENT OF PROBLEM: Implant abutment screw joints tend to loosen under clinical conditions. During impression and prosthesis fabrication, repeated clinical closing and opening of abutment screws may cause component wear and decrease frictional fit of the mating parts, resulting in altered resistance to opening and potential for loss of preload in function. PURPOSE: This study recorded changes in opening torque values due to multiple consecutive closures at a constant torque within and between different abutment/implant (A/I) systems. MATERIAL AND METHODS: Repeated opening-closing cycles were used to simulate in vitro embedment relaxation and component wear of 7 A/I systems from 5 manufacturers. Screw opening torque values were recorded up to 200 consecutive closures at 20 N/cm. RESULTS: A progressive decrease in opening torque values was measured in all implant systems. Significant differences were found between A/I systems. Systems with morse tapered and spline connections consistently maintained a higher resistance to opening force. Percentage torque loss ranged from 3% to 20% on immediate opening, and from 4.5% to 36% for average of first 30 opening/closing cycles. CONCLUSION: Repeated opening and closing of implant abutment screws caused progressive loss of torque retention with variations between systems. This was probably due to a decrease in the coefficient of friction between the mating components.

Manual closing torque in five implant abutment systems: an in vitro comparative study.

STATEMENT OF PURPOSE: A significant percentage of abutment/implant (A/I) assemblies tend to unscrew on functional loading. PURPOSE: This in vitro study evaluated the maximum closing torque generated manually for comparison with recommended closing torque values in 5 implant systems. METHODS: Closing torque generated by 9 operators with 5 manual torque drivers was measured and compared by using a mannequin and torque gauge assembly. RESULTS: Closing torque values were found to be significantly different between operators and between implant systems (P <.0001). Mean closing torque values of 9 operators performing 5 closures for 5 systems ranged from 7 to 14.6 N/cm for habitual closures and from 9.4 to 19.9 N/cm for maximum closures. CONCLUSIONS: The results demonstrated that maximum manual closure did not approach recommended closing torque in any of the system measured. Significant interoperator and intraoperator variability was found in the closing torque with manual drivers, and the driver diameter and grip were probably an important feature in the generation of high closing torque.

VEGI, a novel cytokine of the tumor necrosis factor family, is an angiogenesis inhibitor that suppresses the growth of colon carcinomas in vivo.

A novel member of the tumor necrosis factor (TNF) family has been identified from the human umbilical vein endothelial cell cDNA library, named vascular endothelial growth inhibitor (VEGI). The VEGI gene was mapped to human chromosome 9q32. The cDNA for VEGI encodes a protein of 174 amino acid residues with the characteristics of a type II transmembrane protein. Its amino acid sequence is 20-30% identical to other members of the TNF family. Unlike other members of the TNF family, VEGI is expressed predominantly in endothelial cells. Local production of a secreted form of VEGI via gene transfer caused complete suppression of the growth of MC-38 murine colon cancers in syngeneic C57BL/6 mice. Histological examination showed marked reduction of vascularization in MC-38 tumors that expressed soluble but not membrane-bound VEGI or were transfected with control vector. The conditioned media from soluble VEGI-expressing cells showed marked inhibitory effect on in vitro proliferation of adult bovine aortic endothelial cells. Our data suggest that VEGI is a novel angiogenesis inhibitor of the TNF family and functions in part by directly inhibiting endothelial cell proliferation. The results further suggest that VEGI maybe highly valuable toward angiogenesis-based cancer therapy.

Randomized clinical trial of lifestyle interventions in Pima Indians: a pilot study.

A pilot trial was conducted to test adherence to specific lifestyle interventions among Pima Indians of Arizona, and to compare them for changes in risk factors for diabetes mellitus. Ninety-five obese, normoglycaemic men and women, aged 25-54 years, were randomized to treatments named 'Pima Action' (Action) and 'Pima Pride' (Pride), which were tested for 12 months. Action involved structured activity and nutrition interventions, and Pride included unstructured activities emphasizing Pima history and culture. Adherence to interventions, changes in self-reported activity and diet, and changes in weight, glucose concentrations, and other risk factors were assessed regularly. Thirty-five eligible subjects who had declined randomization were also followed as an 'observational' group and 22 members of this group were examined once at a median of 25 months for changes in weight and glucose concentration. After 12 months of intervention, members of both intervention groups reported increased levels of physical activity (median: Action 7.3 h month(-1), Pride 6.3 h month(-1), p < 0.001 for each), and Pride members reported decreased starch intake (28 g, p = 0.008). Body mass index, systolic and diastolic blood pressures, weight, 2-h glucose and 2-h insulin had all increased in Action members (p < 0.003 for each), and waist circumference had decreased in Pride members (p = 0.05). Action members gained more weight than Pride members (2.5 kg vs 0.8 kg, p = 0.06), and had a greater increase in 2-h glucose than Pride members (1.33 mM vs 0.03 mM, p = 0.007). Members of the observational group gained an average of 1.9 kg year(-1) in weight and had an increase of 0.36 mM year(-1) in 2-h glucose. Sustaining adherence in behavioural interventions over a long term was challenging. Pimas may find a less direct, less structured, and more participative intervention more acceptable than a direct and highly structured approach.

Bone regeneration in extraction sites. Part 2: The staged approach.

The use of guided tissue regeneration in conjunction with implants is a routine procedure in oral implant reconstruction. Three patient reports of the staged approach are presented and discussed. Implants were placed in regenerated bone 9 months after augmentation. Barrier membranes, with and without supporting screws, were used in different types of extraction site defects and followed for 2 years postoperatively.

Functional expression of cloned human splicing factor SF2: homology to RNA-binding proteins, U1 70K, and Drosophila splicing regulators.

SF2 is a protein factor essential for constitutive pre-mRNA splicing in HeLa cell extracts and also activates proximal alternative 5' splice sites in a concentration-dependent manner. This latter property suggests a role for SF2 in preventing exon skipping, ensuring the accuracy of splicing, and regulating alternative splicing. Human SF2 cDNAs have been isolated and overexpressed in bacteria. Recombinant SF2 is active in splicing and stimulates proximal 5' splice sites. SF2 has a C-terminal region rich in arginine-serine dipeptides, similar to the RS domains of the U1 snRNP 70K polypeptide and the Drosophila alternative splicing regulators transformer, transformer-2, and suppressor-of-white-apricot. Like transformer-2 and 70K, SF2 contains an RNP-type RNA recognition motif.

The essential pre-mRNA splicing factor SF2 influences 5' splice site selection by activating proximal sites.

SF2 is a 33 kd protein factor required for 5' splice site cleavage and lariat formation during pre-mRNA splicing in HeLa cell extracts. In addition to its essential role in constitutive splicing, SF2 can strongly influence 5' splice site selection. When pre-mRNAs containing multiple cis-competing 5' splice sites are spliced in vitro, high concentrations of purified SF2 promote the use of the 5' splice site closest to the 3' splice site. However, SF2 discriminates properly between authentic and cryptic splice sites. These effects of SF2 on splice site selection may reflect the cellular mechanisms that prevent exon skipping and ensure the accuracy of splicing. In addition, alterations in the concentration or activity of SF2, and of other general splicing factors, may serve to regulate alternative splicing in vivo.

Purification and characterization of pre-mRNA splicing factor SF2 from HeLa cells.

SF2, an activity necessary for 5' splice site cleavage and lariat formation during pre-mRNA splicing in vitro, has been purified to near homogeneity from HeLa cells. The purest fraction contains only two related polypeptides of 33 kD. This fraction is sufficient to complement an S100 fraction, which contains the remaining splicing factors, to splice several pre-mRNAs. The optimal amount of SF2 required for efficient splicing depends on the pre-mRNA substrate. SF2 is distinct from the hnRNP A1 and U1 snRNP a polypeptides, which are similar in size. Endogenous hnRNA copurifies with SF2, but this activity does not appear to have an essential RNA component. SF2 appear to be necessary for the assembly or stabilization of the earliest specific prespliceosome complex, although in the absence of other components, it can bind RNA in a nonspecific manner. SF2 copurifies with an activity that promotes the annealing of complementary RNAs. Thus, SF2 may promote specific RNA-RNA interactions between snRNAs and pre-mRNA, between complementary snRNA regions, and/or involving intramolecular pre-mRNA helices. Other purified proteins with RNA annealing activity cannot substitute for SF2 in the splicing reaction.

Environmental assessment helps in planning process.

The AHA's planning document, which identifies factors that affect the hospital industry on a nationwide basis, can be a useful reference for individual hospitals in identifying similar factors that affect them on the local level.

Logical thought process key to corporate plan.

Corporate planning allows an organization to determine where it is going and how it will get there. There are two major phases that make up this planning process.

Effects of systemically administered bleomycin or adriamycin with local hyperthermia on primary tumor and lung metastases.

Exposure of cells in tissue culture to bleomycin or Adriamycin during 43 degrees C hyperthermia increased cytotoxicity dramatically compared to exposure at 37 degrees C. This study was designed to test whether this interaction was useful in tumor-bearing animals. C3H mice bearing the KHT tumor were treated with bleomycin (7 or 15 mg/kg) or with Adriamycin (2.5 or 5 mg/kg) with or without local heating of the tumor to 43 degrees C for 30 minutes by 13.56 MHz radiofrequency fields. The effects were assessed by growth delay (mean tumor diameter doubling time) and cure rate. In separate experiments, BALB/c mice bearing EMT6 tumors were treated identically, but tumors were excised 2 hours after treatment and tumor cell survival was assayed by colony formation. Antitumor effects of systemic bleomycin were potentiated by local hyperthermia. The two modalities had to be administered close together in time to observe the potentiation, suggesting a true interaction. There was a "threshold" for bleomycin potentiation in vivo between 42 degrees C and 43 degrees C, just as observed in tissue culture experiments. The antitumor activity of Adriamycin was not potentiated in vivo in these tumor systems except in cell survival experiments at doses higher than those compatible with survival of the host. The toxicity of drug combined with heat was greater than that of either modality alone. Hyperthermia did not adversely affect the incidence or severity of spontaneous lung metastases from KHT tumors. In fact, groups treated with heat and bleomycin had less severe lung metastases than groups treated with bleomycin alone. We conclude that local heating of tumors may be a useful adjunct to systemic bleomycin therapy. In vivo potentiation of Adriamycin by heat, however, could not be demonstrated in these tumor systems.

A primer on antitrust and hospital regulation.

This paper begins with a comparison of the effects of regulation and antitrust litigation on general market dysfunction. The authors then describe the medical marketplace and the effects both regulation and antitrust efforts have had in this arena. They conclude that public policy probably will continue to be concerned with regulation, given that traditional forces do not, and apparently cannot be made to, operate in the health care market. However, through tax benefits, cost-sharing programs, etc., for other-than-traditional modes of care, regulation can be more an instrument for expanding the range of consumer choice than it historically has been.

Thermodynamic properties of polyelectrolyte solutions containing mixtures of monovalent and trivalent counterions.

The osmotic coefficients, heats of dilution, and volume changes on dilution of aqueous solutions containing mixtures of polystyrenesulfonic acid and its lanthanum salt have been determined at 25 degrees C. The curve representing the osmotic coefficient as a function of the equivalent fraction of the acid has a maximum; the corresponding curves for the enthalpy and volume changes on dilution have a sigmoidal shape. Experimental results have been compared with predictions of the theory based on the cell model with cylindrical symmetry. A semiquantitative agreement between theory and experiment has been found.