The role of oxygen radicals in the physiology and pathology of human sperm

Reactive oxygen species in low doses are necessary compound of sperm capacitation and hyperactivation. Superoxide anion, hydroxyl radical and hydrogen peroxide initiate sperm capacitation. The edding of antioxidant enzymes inhibits the spontaneous and induced sperm hyperactivation. The process of capacitation is accompanied with the superoxide anion production output by spermatozoa. High doses of reactive oxygen species block the sperm motility through the inhibition of ATP synthesis by the mitochondrial enzymes and cell membrane compounds injury.     

Route of infection that induces a high intensity of gamma interferon-secreting T cells in the genital tract produces optimal protection against Chlamydia trachomatis infection in mice

The induction of local T helper type 1 (Th1)-mediated cellular immunity is crucial for resistance of mice to genital infection by the obligate intracellular bacterium Chlamydia trachomatis. We tested the hypothesis that the route of immunization that elicits relatively high numbers of chlamydia-specific, gamma interferon (IFN-gamma)-secreting T lymphocytes (ISTLs) in the genital tract would induce optimal protective immunity against reinfection. Female BALB/c mice were infected intravaginally (i.v.), intranasally (i.n.), orally (p.o.), or subcutaneously (s.c.) with C. trachomatis. At days 7, 14, 21, and 28 postinfection, T cells isolated from the genital tract tissues were restimulated with chlamydial antigen in vitro, and the amounts of IFN-gamma induced were measured by a sandwiched enzyme-linked immunosorbent assay method. At day 7 postinfection, i.n.- and i.v.-immunized mice had high levels of chlamydia-specific ISTLs in their genital tracts (203.58 +/- 68.1 and 225.5 +/- 12.1 pg/ml, respectively). However, there were no detectable ISTLs in the genital tracts of p.o.- or s.c.-infected mice. When preinfected mice were challenged i.v. 70 days later, animals preexposed by the i.n. route were highly resistant to reinfection, with greatly reduced chlamydial burden, and suffered an attenuated infection that resolved by day 6 postchallenge. Animals preexposed by the i.v. route were modestly protected, whereas p.o. and s.c. groups were indistinguishable in this regard from control mice. The resistance of i.n.-immunized mice (and to some extent the i.v.-exposed mice) to reinfection was associated with early appearance (within 24 h) of high levels of genital ISTLs compared with mice preinfected by other routes. Furthermore, although i.n. and i.v.-immunized mice had comparable levels of chlamydia-specific immunoglobulin A (IgA) antibodies in their vaginal washes, the levels of IgG2a were four- sixfold higher in i.n.-immunized mice than in any of the other groups. The results suggested that immunization routes that foster rapid induction of vigorous genital mucosal cell-mediated immune (CMI) effectors (e.g., IFN-gamma), the CMI-associated humoral effector, IgG2a, and to some extent secretory IgA produce protective immunity against chlamydial genital infection. Therefore, i.n. immunization is a potential delivery route of choice in the development of a vaccine against Chlamydia.     

Loss of plectin causes epidermolysis bullosa with muscular dystrophy: cDNA cloning and genomic organization

Plectin is a widely expressed high molecular weight protein that is involved in cytoskeleton-membrane attachment in epithelial cells, muscle, and other tissues. The human autosomal recessive disorder epidermolysis bullosa with muscular dystrophy (MD-EBS) shows epidermal blister formation at the level of the hemidesmosome and is associated with a myopathy of unknown etiology. Here, plectin was found to be absent in skin and cultured keratinocytes from an MD-EBS patient by immunofluorescence and immunoprecipitation, suggesting that plectin is a candidate gene/protein system for MD-EBS mutation. The 14800-bp human plectin cDNA was cloned and sequenced. The predicted 518-kD polypeptide has homology to the actin-binding domain of the dystrophin family at the amino terminus, a central rod domain, and homology to the intermediate filament-associated protein desmoplakin at the carboxyl terminus. The corresponding human gene (PLEC1), consisting of 33 exons spanning >26 kb of genomic DNA was cloned, sequenced, and mapped to chromosomal band 8q24. Homozygosity by descent was observed in the consanguineous MD-EBS family with intragenic plectin polymorphisms. Direct sequencing of PCR-amplified plectin cDNA from the patient's keratinocytes revealed a homozygous 8-bp deletion in exon 32 causing a frameshift and a premature termination codon 42 bp downstream. The clinically unaffected parents of the proband were found to be heterozygous carriers of the mutation. These results establish the molecular basis of MD-EBS in this family and clearly demonstrate the important structural role for plectin in cytoskeleton-membrane adherence in both skin and muscle.     

Determination of arginase activity in macrophages: a micromethod

We propose a modification of Schimke's method for urea determination as a valuable micromethod for measuring arginase in activated macrophages. The method exhibits the following advantages: (a) it uses small amounts of samples (approximately 25,000 macrophages per assay); (b) it does not interfere with other related metabolites that are also present in the activated macrophage such as citrulline or arginine; (c) saturating concentrations of the substrate arginine can be used; and (d) it is much more sensitive than Schimke's method and can detect small amounts of urea, in the order of 0.02 mumol.     

Techniques for oxygen transfer measurement in bioreactors: a review

Oxygen is the most essential requirement for aerobic bioprocesses. The microbial growth in a bioreactor depends upon the oxygen transfer rate (OTR). The OTR is widely used to study the growth behavior of microbial and plant cell cultures. The mass transfer coefficient (k_La) determines the magnitude of the OTR. There are many techniques for measuring oxygen concentration and OTR in bioreactors. Zirconia, electrochemical, infrared, ultrasonic and laser cells are used to measure oxygen concentration in the liquid medium. Optical sensors are better alternatives to measure oxygen concentration in small bioreactors. Sulfite oxidation and gassing‐out methods with a Clark‐type electrode have been used for OTR measurements in bioreactors. Many new novel techniques have evolved recently for intermittent and continuous online measurement of OTR/k_La in various types of bioreactors. The present paper gives an overview of various measurement techniques and their limitations and/or suitability for measurement of OTR/k_La in various kinds of bioreactors, especially small bioreactors. Copyright © 2009 Society of Chemical Industry     

The petrolingual ligament: the anatomy and surgical exposure of the posterolateral landmark of the cavernous sinus

The petrolingual ligament is the posteroinferior attachment of the lateral wall of the cavernous sinus, where the internal carotid artery enters the cavernous sinus. The petrous segment of the internal carotid artery finishes and the cavernous segment begins at the superior margin of this ligament. The ligament is surgically important due to its identification as a landmark for dissection of the internal carotid artery during the approaches to posterolateral intracavernous and extracavernous lesions. It can be well exposed after mobilization of the gasserian ganglion, or after the trigeminal root and ganglion have been split along the junction of V2 and V3 (the transtrigeminal approach). The petrolingual ligament was studied in five cadaveric head specimens from ten sides. The size of the ligament was measured, and its anatomical, clinical and surgical importance is discussed.     

Lower limb surveillance following autologous vein bypass should be life long

BACKGROUND: The aim of the study was to investigate whether infrainguinal vein graft surveillance can be stopped at 1 year without prejudicing graft or leg survival. METHODS: Data were collected prospectively on 351 infrainguinal vein bypass grafts (326 patients) that had been entered into a vein graft surveillance programme between 1988 and 1997. RESULTS: Some 104 grafts (30 per cent) developed significant new vein graft stenoses, 95 (91 per cent) of which occurred within 12 months. After 1 year, the risk of developing a significant graft stenosis was 3 per cent per year. Sixty-nine grafted limbs (20 per cent) developed new arterial inflow or run-off stenoses that required intervention, but only 37 (54 per cent) occurred within the first year, after which the risk was 9 per cent per year. The overall risk of developing a new vein graft or arterial stenosis after 1 year was 10 per cent per year. CONCLUSION: The incidence of vein graft stenosis decreases significantly 1 year after operation but there is still at risk of developing potentially graft-threatening arterial stenoses. Legs that have undergone infrainguinal vein bypass grafting should continue to be monitored in a surveillance programme for life.     

Nurse-led shared care diabetes projects: lessons from the nurses' viewpoint

This paper explores the experiences of four nurse practitioners specialised in diabetes care, in the development and implementation of two Dutch nurse-led shared care projects to improve quality of care. The focus is on the impeding factors involved. The nurses' views are compared to those of the 38 participating physicians by using instruments of qualitative research. Both nurses and physicians consider the way shared care delivery has been structured as the most impeding factor, particularly downward substitution of care from doctor to nurse. In the end, lessons are drawn for nurses, doctors and managers, to solve the assessed impediments to shared care.     

Plasma copolymer surfaces of acrylic acid/1,7 octadiene: surface characterisation and the attachment of ROS 17/2.8 osteoblast-like cells

The purpose of this study was: (a) to examine the effect of plasma-gas composition on plasma polymer oxygen/carbon (O/C) ratio, functional group composition and stability in water, and then (b) to examine cell attachment to surfaces containing different concentrations of O/C and functional groups. Oxygen-functionalised surfaces were deposited by means of the plasma copolymerisation of acrylic acid/1,7-octadiene. The use of a diluent hydrocarbon allowed the deposition of surfaces with a range of O/C concentrations. Plasma copolymer surfaces were characterised by X-ray photoelectron spectroscopy (XPS). Changes in functional group composition with % acrylic acid monomer and the non-dispersive and dispersive parts of the surface energy of these plasma copolymers were measured. The solubility of the plasma copolymers was assessed by means of XPS. The degree of attachment of ROS 17/2.8 osteoblast-like cells to plasma copolymer surfaces deemed to be 'stable' in aqueous medium was measured. Tissue culture polystyrene (TCPS) was included as a control. Attachment was found to be greatest to the plasma copolymer surface with an O/C of 0.11. This surface had a carboxylic acid concentration of ca. 3%. Attachment did not correlate with increased surface wettability (i.e. the non-dispersive component of the surface energy).