Oxidative stress in neonatology: a review.

Free radicals are highly reactive oxidizing agents containing one or more unpaired electrons. Both in human and veterinary neonathology, it is generally accepted that oxidative stress functions as an important catalysator of neonatal disease. Soon after birth, many sudden physiological and environmental conditions make the newborn vulnerable for the negative effects of oxidative stress, which potentially can impair neonatal vitality. As a clinician, it is important to have in depth knowledge about factors affecting maternal/neonatal oxidative status and the cascades of events that enrol when the neonate is subjected to oxidative stress. This report aims at providing clinicians with an up-to-date review about oxidative stress in neonates across animal species. It will be emphasized which handlings and treatments that are applied during neonatal care or resuscitation can actually impose oxidative stress upon the neonate. Views and opinions about maternal and/or neonatal antioxydative therapy will be shared.

In vitro effect of isotocin on ovarian tunica albuginea contractility of gilthead seabream (Sparus aurata L.) in different reproductive conditions.

Contractions of ovarian tunica albuginea, the teleostean cystovary wall layer containing smooth muscle fibres, facilitate oocytes and fluids movements within the ovary, oocytes ovulation and spawning. Fish isotocin, the homologue hormone of mammalian oxytocin, plays a significant role in ovulation, oviduct contraction and spawning. In the present study, ovarian wall spontaneous contraction, as well as isotocin in vitro effect on tunica albuginea contractility, was analysed in female seabream in different reproductive conditions: vitellogenesis, regressing (post-spawning) and extensive atresia. Tunica albuginea spontaneous contractility was recorded using ovary wall strips mounted in an organ bath containing modified Ringer's solution. The strips were then exposed to cumulative doses of isotocin (6, 30, 60 µg/ml). Female seabream in regressing condition exhibited the highest level of tunica albuginea spontaneous contraction amplitude compared with the other two groups. Only fish in vitellogenesis state showed a significant increase in contraction amplitude after isotocin administration at the dose of 30 µg/ml. The same group exhibited also a significant isotocin dose-dependent decrease in the contractile frequency. These results confirm the involvement of isotocin in stimulating tunica albuginea contractile activity during the oestrogen-regulated phase of vitellogenesis, whereas the absence of significant effects of isotocin on ovarian contractility in fish at the regressing state might be ascribed to the occurrence of a contractile activity autonomously regulated by the internal pacemaker system. The absence of exposed isotocin receptors could explain the lack of effects of the isotocin administration in seabream showed extensive atresia of the follicular cells.

Ovarian contractility in reared gilthead seabream (Sparus aurata L.) in different phases of the reproductive cycle.

Spontaneous ovarian tunica albuginea contractility was evaluated in gilthead seabream (Sparus aurata L.) at different phases of the reproductive cycle. Fourteen adult females were sampled from February to November 2012 in a commercial fish farm, and ovaries were removed and processed for histological and contractility analyses. Fish reproductive stages were evaluated on haematoxylin-eosin-stained ovary sections or by simple macroscopic observation of hydrated oocytes in spawning individuals. Tunica albuginea spontaneous contractility was recorded by using ovary wall strips mounted in an organ bath containing modified Ringer's solution. Ovary macro- and microscopic analyses allowed the identification of three different reproductive conditions: vitellogenesis, spawning and regressing. The gilthead seabream tunica albuginea was capable to contract spontaneously, and significant differences were found in mean contraction amplitude among the three reproductive states, with the highest value recorded in individuals in regressing condition and the lowest in individuals at spawning stage. No differences in mean contractility frequency among the three different groups were found. Possible involvement of spontaneous contractility in facilitating developing follicle advancement towards the ovarian lumen within the ovary and in supporting recovery of regressing ovaries may be hypothesized. The low contractility observed during the final oocyte maturation and spawning phases does not seem to support a role of tunica albuginea during ovulation, which could conversely involve theca cell contraction. Alternatively, possible single instantaneous contractions of tunica albuginea muscle fibres, not detected in the present study, could occur during ovulation in response to neuro-hormonal stimulations; a role of abdominal wall musculature in ovary "squeezing" and consequent release of ovulated eggs cannot be excluded.

Oxidative stress during pregnancy in the sheep.

During physiological pregnancy, all tissues and, mostly, placenta and foetus require high amounts of oxygen. Reactive oxygen species (ROS), generated both by mother and foetus, are implicated in foetal growth because they promote replication, differentiation and maturation of cells and organs. Nevertheless, ROS excess, if not properly counterbalanced, may lead to an alteration in cell constituents, with harmful effects both on mother and foetus.ROS exert a biphasic effect because adequate ROS concentration is essential for embryo development, implant, foetal defence against uterine infections, steroidogenesis, pregnancy maintainance and partum. On the other hand, an uncontrolled ROS generation, beyond physiological antioxidant defences, may lead to embryo resorption, placental degeneration with subsequent alteration in maternal-foetal exchanges, delay in foetal growth, pregnancy interruption, stillbirths. This review investigates the mechanisms underlying ROS generation and effects, throughout physiological and pathological pregnancy in sheep, with a look to antioxidants and their importance in such a critical phase of the reproductive cycle of the sheep.

Contractile effect of rifaximin on bovine uterus in the presence of steroid hormone antagonists.

This in vitro study investigated the modulatory effect of rifaximin on bovine uterus contractility, in both phases of the oestrous cycle, with and without the steroid hormones that are predominant in the respective phases: oestrogen in the follicular phase and progesterone in the luteal phase. The procedures were conducted in an isolated organ bath by using rifaximin alone (10-4 M) and in association with the steroid hormone antagonists (10-5 M) tamoxifen (oestrogen antagonist) in the follicular phase and mifepristone (progesterone antagonist) in the luteal phase. The results indicated that rifaximin can stimulate uterine contractility. Indeed, the administration of rifaximin in the presence of tamoxifen or mifepristone increased the tonic activity of the uterus in both phases of the cycle. This result is clinically significant because rifaximin might also enable, in vivo, a simultaneous increase in uterine cleaning and the antimicrobial action against bacteria during the first 14 days postpartum, during the development of acute metritis.

Scopolamine butylbromide decreases the xylazine-mediated contractility in bovine pregnant uteri.

The objective of this in vitro study was to evaluate and compare the effects of scopolamine butylbromide (Spasmolax®) on xylazine-sensitized bovine pregnant uterine strips, at different stages of pregnancy. The procedures were carried out in isolated organ bath. Uterine motility, expressed with amplitude, frequency of contractions as well as the area under the curve, was recorded in different stages of pregnancy and data were collected at 5-min intervals starting 5 min before treatment until 10 min after treatment (5-min after xylazine administration and 5-min after scopolamine butylbromide addition). The results suggest that scopolamine butylbromide might decrease the tonic effect induced by xylazine on bovine pregnant uteri from 0-30 days to 240-270 days.

Effect of neostigmine on contractility of equine pre-ovulatory follicles: An in vitro study.

In this study, the Authors investigated the modulatory effect of three single doses (10-6, 10-5, and 10-4 M) of neostigmine on the spontaneous contractility of equine pre-ovulatory follicles in an isolated organ bath, to establish the relationship between this acetylcholinesterase inhibitor and ovulation, in the mare. The results indicate that neostigmine increases pre-ovulatory contractility in equine follicles at each dose, but in a different manner. Indeed, the rise in contractility induced by neostigmine at 10-6 M and 10-4 M was phasic, while at 10-5 M it was tonic. The data obtained indicate possible implications of these drugs in the pharmacological modulation of equine ovulation.

Effects of d-cloprostenol on different layers and regions of the bovine uterus during the follicular and luteal phases.

INTRODUCTION: D-cloprostenol is a synthetic PGF2α, commonly used in bovine reproduction, that increases myometral contractility. However, little is known regarding its contractile behaviour and how it depends on the reproductive state and uterine topography (regions and muscular layers). HYPOTHESIS AND OBJECTIVES: These aspects would affect the action of d-cloprostenol on the uterus. Therefore, we hypothesize a possible use of this drug at the time of artificial insemination, to improve conception rates and, in the post-partum, in order to accelerate uterine involution in dairy cattle. The purpose of the present study was to investigates the modulatory effect of d-cloprostenol on contractility of the bovine uterine region (horn and corpus) and their muscle layers (circular and longitudinal), in follicular and luteal phases. To our knowledge, motility effects of d-cloprostenol on different regions from healthy bovine uterus have not been described up to now. MATERIALS AND METHODS: Uterine specimens were collected from uterine body and horn of cattle in the follicular (n = 28) and luteal phase (n = 32) of the estrous cycle at slaughter. Two strips were prepared from each regions corresponding to the circular and the longitudinal muscular layers, respectively. Samples were cultured in an organ bath, exposed to synthetic prostaglandin (1 µM d-cloprostenol) and their contractile activity was monitored for 10 min. The functionality of the strip throughout the experiment was tested by a dose of carbachol (10-5 M). RESULTS: The mean basal amplitude of contractions was higher in the follicular compared to the luteal phase in uterine horn samples, but not in muscles collected from the uterine body. The amplitude of contractions increased after d-cloprostenol administration in all tissues with a greater increase in samples from cattle in the follicular phase. The frequency of contractions increased after d-cloprostenol administration in longitudinal but not in circular fibrees. CONCLUSION: The contractile responses to d-cloprostenol in both horn and corpus were strongest in the circular muscles but weak in the longitudinal muscles.

Oxytocin plus antibiotics: A synergism of potentiation to enhance bovine uterine contractility.

This in vitro study investigates the modulatory effect of three antibiotics (amoxicillin, enrofloxacin, and rifaximin) on contractility of the bovine uterine tissue, in follicular and luteal phases. The evaluation of the effects of these antibiotics (10(-4) M) was performed on oxytocin-induced contractility. The decision to test these antibiotics with the oxytocin (10(-6) M) comes from the reported ability of these combinations of hinder the antibiotic resistance and the formation of bacterial biofilms. The procedures were carried out in isolated organ bath, and the contractile functionality of the strip throughout the experiment was evaluated after a dose of carbachol (10(-5) M). The results demonstrate the different modulatory activity of these antibiotics, on the plateau of contraction induced by oxytocin, in both phases of the estrus cycle. The differing individual antibiotic effects of our testing made it possible to identify, only in some cases. Rifaximin in the follicular phase and enrofloxacin in both phases of the estrous cycle, induced a synergistic enhancement (potentiation) of uterine strip contraction induced by oxytocin. This result is thought important because these associations might enable, in vivo, a simultaneous increase of uterine cleaning and the antimicrobial action on bacteria in planktonic form and of those organized in biofilms.

Lidocaine decreases the xylazine-evoked contractility in pregnant cows.

The objective of this in vitro study was to evaluate and compare the effects of xylazine on basal uterine contractility of bovine pregnant uterine strips and that of lidocaine on xylazine-sensitized bovine pregnant uterine strips, at different stages of pregnancy. Basal contractility was evaluated in an isolated organ bath and the functionality of the strips throughout the experiment was evaluated using a dose of carbachol (10(-5)M). Uterine motility, expressed with amplitude, frequency of contractions as well as the area under the curve, was recorded in different stages of pregnancy and data were collected at 15-min intervals (5-min before and 5-min after xylazine administration and 5-min after lidocaine addition on the plateau contraction induced by xylazine). Uterine motility increased in all the stages of pregnancy after xylazine addition and gradually decreased after treatment with lidocaine. These data suggest that lidocaine might decrease the tonic effect induced by xylazine on bovine pregnant uteri.

Application of an innovative technique for unilateral ovariectomy in dairy cows.

This report describes an innovative unilateral ovariectomy technique for the surgical treatment of follicular cysts in dairy cows. Five cows, with a diagnosis of follicular cysts, were submitted to unilateral ovariectomy via a paralumbar fossa approach, in standing position. The linear cutter proved useful for clamping the ovary, stapling the vessels and cutting in one stroke, thus reducing surgery times. After unilateral ovariectomy, all cows underwent heat 7-30 days after surgery, and three cows became pregnant. All cows showed increased milk production. The results of this case report showed that flank ovariectomy, performed in this way, is an efficient, low-risk technique for surgical treatment of follicular cysts in dairy cows.

Dynamics of the progesterone and cholesterol concentrations within the bovine corpus luteum cavity.

The aim of this study was to examine the concentrations of progesterone (P4) and cholesterol (CHOL) in fluid of cavitary corpus luteum (CL) and in serum of dairy cattle. Cavitary corpora lutea, collected from cows at a local abattoir, were divided in four stages of development, based on days of the estrous cycle (stage I: 1-4days; stage II: 5-10days; stage III: 11-17days; stage IV: 18-20). Fluid of the their cavity was aspirated and P4 and CHOL concentrations were evaluated. The concentrations of P4 in CL cavity fluids were very high (1640-4666.67ng/mL) and showed a peak at the stage III. CHOL values were similar to those of serum and the highest levels were found in the stage I.

Tumor necrosis factor alpha (TNF alpha) and neurological diseases. Failure in detecting TNF alpha in the cerebrospinal fluid from patients with multiple sclerosis, AIDS dementia complex, and brain tumours.

The presence of tumor necrosis factor alpha (TNF alpha)/cachectin was investigated in 180 paired cerebrospinal fluid (CSF) and serum samples from patients with neurological diseases, and in five paired CSF and serum samples of Macaca cynomolgus monkeys with acute monophasic experimental autoimmune encephalomyelitis (AMEAE). TNF alpha was never detected in human CSF, even when an extensive demyelination was documented (active multiple sclerosis, acquired immunodeficiency syndrome (AIDS) dementia complex). Only one Macaca with AMEAE had detectable levels of TNF alpha in CSF but not in serum, suggesting an intrathecal synthesis of this cytokine in AMEAE.

Macrophage-colony stimulating factor (M-CSF) in the cerebrospinal fluid.

In a series of 145 cases with neurological diseases, macrophage-colony stimulating factor (M-CSF) was detected in cerebrospinal fluid of patients with brain tumors, bacterial meningitis, and less frequently, AIDS-dementia complex. Granulocyte-colony stimulating factor (G-CSF) was found only in patients with bacterial meningitis; granulocyte-macrophage (GM)-CSF was never detected. These findings suggest that M-CSF may play an important intrathecal immunoregulatory role in neoplastic and infectious diseases of the central nervous system.

Free light chains of immunoglobulins in the cerebrospinal fluid of human immunodeficiency virus type 1-infected patients.

The presence of immunoglobulin (Ig) free light chains (FLC) was investigated in the cerebrospinal fluid (CSF) of human immunodeficiency virus type 1 (HIV-1)-infected patients. Intrathecal synthesis of FLC was demonstrated in 80% of the patients, even in the absence of oligoclonal Ig. The FLC patterns were characterized by restricted heterogeneity with regard to both isoelectric point and the molecular weight, and were mainly composed by dimers rather than monomers. A striking prevalence of lambda FLC was also observed. Local production of FLC can be taken as a marker of an ongoing immunopathological process within the central nervous system (CNS) in HIV-1-infected patients. A deregulation of Ig production by intrathecally activated B cells may be hypothesized.

Effect of parenteral administration of GM1 on cytokines and anti-ganglioside antibody patterns. Preliminary report in normal human individuals.

To assess the effects of monosialoganglioside GM1 on some immunological parameters, 12 healthy men were treated with 100 mg GM1 i.m. daily for 15 days. Before and after treatment, the following were studied: (1) serum levels of antibodies against GM1, asialo-GM1 (aGM1), GM2 and GD1b; (2) serum levels of interleukin (IL)-1 beta, IL-2, soluble IL-2 receptor (sIL-2R), tumor necrosis factor-alpha (TNF-alpha), and interferon-gamma (IFN-gamma); (3) IL-1 beta and TNF-alpha production by peripheral blood monocytes (PBMO). Anti-ganglioside antibody and cytokine serum levels were not affected by exogenous GM1 administration with the exception of a transient increase in anti-GM1 antibody titer observed in one subject. In addition, no inhibition of IL-1 beta and TNF-alpha production by PBMO was observed. These preliminary data do not support a potential immunogenic or immunomodulatory function for in vivo administered GM1.

A longitudinal study on IL-2, sIL-2R, IL-4 and IFN-gamma in multiple sclerosis CSF and serum.

The cerebrospinal fluid (CSF) and serum levels of interleukin-2 (IL-2), soluble IL-2 receptor (sIL-2R), interleukin-4 (IL-4) and interferon-gamma (IFN-gamma) were longitudinally investigated in 20 multiple sclerosis (MS) patients. There were 80 paired CSF and serum samples (range 2-8 per patient) covering a 1-5 year (mean 2.5 year) period. Increased levels of IL-2 and sIL-2R were found in 56 and 71%, respectively, of MS sera. In all patients, one or several sera (totally 89%) exhibited values above the normal range for either one of the components or both. The occurrence of IL-2 or sIL-2R positive CSF specimens was much lower, 15 and 9%, respectively. Only 3 MS sera (from one patient) had clearly detectable IL-4 and no CSF samples were definitely positive. IFN-gamma was undetectable in all serum and CSF specimens. No correlations were found between the immunological parameters and the clinical disease activity. The cytokine patterns in MS give strong support for the presence of a systemic T-cell activation. Furthermore, the data argue for a predominant activation of an IL-2- and sIL-2R-producing but not IL-4-producing T-helper (Th) lymphocyte subpopulation, Th1/CD4 + CD45R + cells.

Transferrin receptors in rat central nervous system. An immunocytochemical study.

Using an immunocytochemical method we demonstrated the presence of TfR on adult rat neurons, particularly in the cerebral cortex and brain stem. The monoclonal antibody (mab) against rat TfR (clone OX 26) stained neurons of all cortical layers and in the brain stem where the reaction was most evident. Purkinje cells in the cerebellum and scattered neurons in the gray matter of the cervical spinal cord were weakly stained. Choroid plexus cells also reacted with the mab against TfR whereas oligodendrocytes in the cerebral white matter were faintly outlined by the mab. The presence of TfR on endothelial cells of brain capillaries was here confirmed.

Immune activation in multiple sclerosis: study of IL-2, sIL-2R, and gamma-IFN levels in serum and cerebrospinal fluid.

Serum and cerebrospinal fluid (CSF) levels of interleukin-2 (IL-2), soluble IL-2 receptor (sIL-2R), and gamma-interferon (gamma-IFN) were measured in multiple sclerosis (MS) patients, human immunodeficiency virus type 1 (HIV-1)-infected patients and normal controls (NC). Increased levels of both IL-2 and sIL-2R were found in MS serum. Moreover, 11 of 50 MS patients showed detectable levels of IL-2 in the CSF. HIV-1-infected patients had increased levels of sIL-2R in serum and, less frequently, in the CSF. gamma-IFN was never detected in serum and CSF of all the patients studied. These findings confirm preliminary reports, further stress a systemic T-cell activation in MS, and support the hypothesis that an immunologic disorder exists in such patients.

Modulatory effect of three antibiotics on uterus bovine contractility in vitro and likely therapeutic approaches in reproduction.

This in vitro study investigates the modulatory effect of three antibiotics (amoxicillin, enrofloxacin, and rifaximin) on contractility of the bovine uterine tissue in follicular and luteal phases. The effects of these antibiotics at three single doses (10(-6), 10(-5), and 10(-4) M) on their basal contractility were evaluated in isolated organ bath. The functionality of the strip throughout the experiment was evaluated by a dose of carbachol (10(-5) M); the obtained effect had to be repeatable (difference of ≤20%) that is comparable to that induced by the previous administration of the same substance. The results demonstrate the different modulatory activities of these antibiotics on uterine contractility in follicular and luteal phases. The effects induced by amoxicillin and enrofloxacin are opposite: the first relaxes and the second increases the uterine contractility in both cycle phases. Instead, the activity of rifaximin varies depending on the phase of estrous cycle: it increases in the follicular phase and relaxes in the luteal phase. The obtained data provide the hypothesis of possible implications of these drugs in the pharmacologic modulation of uterine contractions. Their action at this level, associated with their specific antimicrobial effects, could suggest using these antibiotics for the treatment of diseases related to postpartum or infections that may occur in pregnant cattle, by virtue of their effects on myometrial contractility too.