The effect of twin-to-twin delivery time intervals on neonatal outcome for second twins.

BACKGROUND: The objective was to examine the effect of twin-to-twin delivery intervals on neonatal outcome for second twins. METHODS: This was a retrospective, hospital-based study, performed at a university teaching hospital in Western Sweden. Twin deliveries between 2008 and 2014 at ≥32 + 0 weeks of gestation, where the first twin was delivered vaginally, were included. Primary outcome was a composite outcome of metabolic acidosis, Apgar < 4 at 5 min or peri/neonatal mortality in the second twin. Secondary outcome was a composite outcome of neonatal morbidity. RESULTS: A total of 527 twin deliveries were included. The median twin-to-twin delivery interval time was 19 min (range 2-399 min) and 68% of all second twins were delivered within 30 min. Primary outcome occurred in 2.6% of the second twins. Median twin-to-twin delivery interval was 34 min (8-78 min) for the second twin with a primary outcome, and 19 min (2-399 min) for the second twin with no primary outcome (p = 0.028). Second twins delivered within a twin-to-twin interval of 0-30 min had a higher pH in umbilical artery blood gas than those delivered after 30 min (pH 7.23 and pH 7.20, p <  0.0001). Secondary outcome was not associated with twin-to-twin delivery interval time. The combined vaginal-cesarean delivery rate was 6.6% (n = 35) and the rate was higher with twin-to-twin delivery interval >  30 min (p <  0.0001). CONCLUSIONS: An association, but not necessarily a causality, between twin-to-twin delivery interval and primary outcome was seen. An upper time limit on twin-to-twin delivery time intervals may be justified. However, the optimal time interval needs further studies.

Cartilage oligomeric matrix protein (COMP) is modified by intra-articular liposomal clodronate in an experimental model of arthritis.

OBJECTIVE: High-dose liposomal bisphosphonates exert apoptotic effects. This work studies the chondroprotective and anti-inflammatory properties of intra-articularly administered low-dose, non-cytotoxic liposomal clodronate. METHODS: Antigen induced arthritis in rabbits was treated with intra-articular injections of liposomal clodronate. Drug effects on cartilage oligomeric matrix protein COMP was assessed using immunohistochemistry and morphometry of synovial membrane and hyaline articular cartilage. RESULTS: COMP remained close to normal in liposomal clodronate treated superficial articular cartilage compared to a significant loss of COMP in arthritis controls treated with empty liposomes. The middle and deep layers of the hyaline articular cartilage were characterized by highly increased COMP expression in liposomal clodronate treated AIA joints compared to controls. In contrast to cartilage, synovial COMP expression was slightly decreased as a result of liposomal clodronate treatment. CONCLUSION: Low-dose, non-cytotoxic liposomal clodronate exerts a dichotomous effect on synovial membrane and articular cartilage COMP in the AIA model. COMP is a useful inflammation marker in the synovial tissue, but it also contributes to the structural integrity of the hyaline articular cartilage forming bridges between type II and IX collagens. Enhancement of COMP in clodronate treated AIA cartilage suggests a chondroprotective and anti-inflammatory effect in the inflammatorily damaged and mechanically strained cartilage.

Biodegradable polydioxanone and poly(l/d)lactide implants: an experimental study on peri-implant tissue response.

Several implants for orbital wall fracture treatment are available at the present, but they have drawbacks: resorption, risk for migration and foreign body reaction. Alloplastic resorbable implants would be advantageous: no removal operation and no donor side morbidity. The purpose of this study was to evaluate the foreign body reaction, capsule formation and mechanical properties of two bioresorbable implants. PDS and SR-P(L/DL)LA mesh sheet (70/30) with solid frame (96/4) implants (SR-P(L/DL)LA 70,96) were placed into subcutaneous tissue of 24 rats. Immunohistochemistry was used to evaluate reactivity for Tn-C, alpha-actin, type I and III collagens and two mononuclear cells: T-cells and monocyte/ macrophage. GPC, DSC and SEM were performed. Student's t-test or nonparametric Kruskall-Wallis test were used for statistical analysis. Histology of peri-implant capsule exhibited an inner cell-rich zone and an outer connective tissue zone around both materials. Tn-C reactivity was high in the inner and alpha-actin in the outer zone. At the end of the study, the difference of type I collagen versus type III collagen reactivity in inner zone was statistically significant (P<0.0001) as was the difference of type I collagen versus type III collagen reactivity in outer zone (P<0.0001). Immunohistochemistry did not reveal any statistical differences of T-cell and monocyte/macrophage reactivity around PDS versus SR-P(L/DL)LA 70,96 implants, nor any differences as a function of time. PDS were deformed totally after 2 months. SR-P(L/DL)LA 70,96 implants were only slightly deformed during the follow up of 7 months. PDS degraded rapidly in SEM observation. Particles were detaching from surface. SEM observation revealed that polylactide implant was degrading from the surface and the inner porous core became visible. The degradation came visible at 7 months. There were cracks in perpendicular direction towards to the long axis of the filaments. M(w) of PDS decreased fast compared to the polylactide implant. Foreign body reaction was minimal to both materials but continued throughout the whole observation period. Mechanically PDS was poor, it looses its shape totally within 2 months. It cannot be recommended for orbital wall reconstruction. New mesh sheet-frame structure (SR-P(L/DL)LA 70,96) approved to be mechanically adequate for orbital wall reconstruction. It seems not to possess intrinsic memory and retains its shape. The resorption time is significantly longer compared to PDS and is comparable to other studied P(L/DL)LA copolymers. Thus, the new polylactide copolymer implant may support the orbital contents long enough to give way to bone growth over the wall defect.

Determination of gallic acid in wood dust as an indicator of oak content.

A high-performance liquid chromatography (HPLC) method was developed for the detection of extracted gallic acid in wood dust. Gallic acid is a polyphenol present in carcinogenic oak wood dust, but not in beech, ash, pine or spruce dusts, as confirmed by HPLC analyses. The method involved the extraction of gallic acid from the oak dust, followed by liquid chromatographic analysis. The correlation coefficient for the share of oak dust vs. the gallic acid concentration of wood dust was 0.995. The method was tested with oak wood dust samples collected on polycarbonate membrane filters during an 8 h workshift in a floor board factory, where the dust content of the air samples was determined gravimetrically. The oak dust and the gallic acid concentrations varied from 0.2 to 13.8 mg m-3 and from 0.03 to 3.8 micrograms m-3, respectively. These parameters were linearly correlated with a correlation coefficient of 0.95. The airborne gallic acid determination is a useful technique to confirm occupational exposure to oak wood dust, a recognized human carcinogen.

No lymphokines in T-cells around loosened hip prostheses.

Research results have been contradictory about the role of lymphocytes and immune response in aseptic loosening of total hip replacement (THR). Conclusive evidence is still lacking in spite of extensive in vivo and in vitro studies. Our study was designed to check whether T-cells were activated and if they produced lymphokines in synovial membrane-like interface tissue around loosened THRs. Tissue sections were stabilized and permeabilized to allow the cytokine-specific antibodies to penetrate through the cell membrane and the membranes of intracellular organelles. This technique, combined with computer-assisted image analysis, permits the detection and quantitation of lymphokine-producing cells. We found that the number of T-cells was low, and none of the T-cells was activated, as shown by the absence of interleukin-2 receptor (IL-2R) immunoreactivity. There was no cell producing lymphokines, such as interleukin-2 (IL-2), interferon-gamma (IFN-gamma), and tumor necrosis factor-beta (TNF-beta). Our results suggest that T-cell-mediated immune response is not actively involved in aseptic loosening of THR.

Expression of parathyroid hormone related protein in the tissue around loosened hip prostheses.

OBJECTIVE: To investigate the eventual presence and cellular source ofparathyroid hormone related protein (PTHrP) in the synovial-like interface membrane from aseptic loosening of total hip replacement (THR). METHODS: A polyclonal rabbit antiserum to the amino-terminal peptide of human PTHrP was used to stain 10 interface membrane samples from loose THR and 10 synovial tissue samples from hip osteoarthritis (OA). Quantitative microscopic assessment was done with a computer-assisted image analysis system. Western blotting was applied to verify the presence of PTHrP in both tissue samples. Double immunofluorescence labelling aimed to reveal the cellular sources of PTHrP. RESULTS: Immunoreactive PTHrP was found in all interface membrane and OA synovial tissue samples. The number of PTHrP positive cells in interface membrane was much higher than in OA synovial tissue. Positive cells were most commonly seen in the lining-like layers and sublining area of interface membrane. Double immunofluorescence labelling showed that most macrophages and fibroblasts in interface membrane were PTHrP positive. Western blotting revealed the 24-25 KD bands in both tissue samples. CONCLUSIONS: PTHrP expression is upregulated in interface membrane around loosened hip prostheses. Locally accumulated PTHrP may contribute to periprosthetic osteolysis and aseptic loosening of THR through its direct effects on bone, or indirectly via the induction of inflammatory mediators.

Analysis of oak tannins by liquid chromatography-electrospray ionisation mass spectrometry.

Extractable tannins were analysed by liquid chromatography-electrospray ionisation mass spectrometry in two oak species, North American white oak (Quercus alba) and European red oak (Quercus robur). They mainly included various glucose gallic and ellagic acid esters. The structures were partially determined, and they included grandinin/roburin E, castalagin/vescalagin, gallic acid, valoneic acid bilactone, monogalloyl glucose, digalloyl glucose, trigalloyl glucose, ellagic acid rhamnose, quercitrin and ellagic acid.

Evaluation of hazards in CO2 laser welding and related processes.

High-power CO2 lasers are used extensively in various industrial applications. In most cases they form part of open-beam equipment and have a power of several kilowatts, and are thus designated as Safety Class 4 systems. In addition to the invisible i.r. laser beam (10.6 microns), u.v. radiation and visible light may be emitted. In the present work a power meter controlled by microprocessor and a spectroradiometer measured the scattered or reflected laser radiation. In addition, concentration levels of welding and cutting fumes and of pyrolysis products of plastics were determined during various laser processes. Finally, a safety analysis was performed to compare the hazards of laser welding with those of conventional welding methods: this showed that the use of laser systems can eliminate many traditional risks, but the worker must be protected not only against the coherent laser beam, but also from incoherent blue light and u.v. radiation.

Urinary excretion of chlorinated phenols in saw-mill workers.

The excretion and conjugation of chlorophenols were studied in workers exposed to 2,4,6-tri-, 2,3,4,6-tetra-, and pentachlorophenolates, the main components of the chlorophenolate product manufactured by direct chlorination of phenol. The workers were exposed in two different saw mills in which sodium chlorophenolate was used for treatment of lumber during the warm season. Urine specimens were collected at the end of the treatment season as well as at the start of a new treatment period in the spring. Serum specimens were collected towards the end of the treatment period. Total and unconjugated chlorophenols were analyzed with a gas chromatographic method. The maximal concentrations of urinary 2,4,6-tri-, 2,3,4,6-tetra- and pentachlorophenol at the end of the lumber-treatment period were 1-11.8, 3.4-17.3, and 0.2-0.9 mumol/l, respectively, and the average apparent half-times calculated using a one-compartment model were 18 h, 4.3 days and 16 days, respectively. For 2,3,4,6-tetrachlorophenol, the data of some subjects showed a better fit with a two-compartment model; the corresponding half-times were 5.3 and 26 days. During the continuous-exposure period the average serum levels of tetra- and pentachlorophenol were rather similar before and after the working day: 2.79 +/- 1.78 mumol/l for tetrachlorophenol and 0.85 +/- 0.4 mumol/l for pentachlorophenol. Renal clearance values for tetra- and pentachlorophenol were related to urine flow and indicated tubular reabsorption. At low concentrations, sulfate conjugation was dominant. With increasing chlorophenol concentrations the proportion of glucuronide conjugation was increased, especially for pentachlorophenol.

Urinary chlorophenols in sawmill workers.

The concentration of urinary chlorophenol was assayed for 230 sawmill workers. Information on the work tasks was obtained through questionnaires from occupational health centres. The workers were divided into three groups on the basis of the type of exposure: (1) those with skin absorption as the main route, (2) those with skin and respiratory route of equal importance and (3) those with respiratory tract as the main route. The concentrations of urinary chlorophenol were higher in workers with skin absorption as the main route (median concentration: 7.8 mumol l-1; range 0.1 to 210.9 mumol l-1) than in those with both routes of equal importance (1.4 mumol l-1; range 0.1 to 47.8 mumol l-1, P less than 0.001) or in those with mainly respiratory route (0.9 mumol l-1; range 0.1 to 13.3 mumol l-1, P less than 0.001). The urinary chlorophenol concentration was below 15 mumol l-1 in all workers with the lungs as the main absorption route. In nine out of 112 workers whose main absorption route was the skin, the urinary chlorophenol values were above 50 mumol l-1. Six were loaders when the through-dipping method was used. In two of them urinary chlorophenol concentrations were as high as 170.8 and 210.9 mumol l-1. These results emphasize the need to develop and use simple methods of protection against skin contact with chlorophenols.

Chlorophenol exposure in sawmills.

Personnel exposures to chlorophenols were measured in ten Finnish sawmills where a chlorophenolate salt formulation was used for the blue stain control of sawed wood. The concentrations of chlorophenols in the air were usually well below the occupational limit value of 0.5 mg/m3. However, high concentrations (above 10 mg/m3) were measured inside heated kilns. Additionally, high concentrations were detected in the urine of workers whose skin came into contact with chlorophenol solution, indicating that chlorophenols are rapidly absorbed through the skin. The concentrations of chlorophenols in the air were low in trimming-grading plants where treated boards are handled, but some of the chlorophenols was bound to wood dust which is deposited mainly in the nose. The risks associated with the impurities contained in chlorophenol preparations (chlorinated dibenzodioxins and dibenzofurans) and the need for epidemiologic studies on possible cancer risks in sawmill work are discussed.