bluuebunny/crossref_metadata_2025 huggingface dataset:
In vivo Micromechanical Measurements of the Organ of Corti in the Basal Cochlear Turn
Authors: Nuttall Alfred L. , Ren Tianying , de Boer Egbert , Zheng Jiefu , Parthasarathi Anand , Grosh Karl , Guo Menghe , Dolan David
Published: April 2003

Cochlear mechanical measurements of organ of Corti motion are generally accomplished in the apical or basal turn as in vivo or in vitro studies. In the apex it is possible to observe and measure tectorial membrane vibration as well as vibrations of structures such as the reticular lamina or the basilar membrane (BM). However, compared to the basal turn, cochlear amplification and nonlinearity are not strong in the apex. Basal turn studies have typically been limited to point location measurements of the BM but improved technology for laser interferometry is now making possible the spatial mapping of BM motion. The ‘complexity’ of BM motion in the radial direction (particularly the phase variation) is important to new models of cochlear wave amplification. In future work it may be possible to learn about vibration of structures within the organ of Corti.
The Inner Hair Cell Synaptic Complex: Physiology, Pharmacology and New Therapeutic Strategies
Authors: Puel Jean-Luc , Ruel Jérôme , Guitton Matthieu , Wang Jing , Pujol Rémy
Published: April 2003

Within the cochlea, the sensory inner hair cells (IHCs), which transduce mechanical displacement of the basilar membrane into neural activity, release glutamate to act on postsynaptic receptor channels located on dendrites of primary auditory neurons. In turn the activity of the postsynaptic auditory dendrites is modulated by a variety of lateral efferent neurotransmitters. This presentation reviews the most recent findings obtained at the IHC synaptic complex with an original technique, namely coupling auditory nerve single unit recordings with multibarrel intracochlear perfusions. Two types of results are emphasized: (1) in physiological conditions, the activity of auditory nerve fibers involves AMPA, but not kainate or NMDA receptors, and (2) this activity is tonically modulated by dopamine, one of the lateral efferent neurotransmitters. With the increasing knowledge of molecular mechanisms involved at the first synaptic complex in the cochlea, it is now possible to envisage local treatments for spiral ganglion neurons. These treatments, available experimentally, may be used in the near future: either to protect spiral ganglion neurons against excitotoxic injury (traumatic and/or ischemic sudden deafness), or to prevent excitotoxic-induced hyperexcitability (probably the starting point of most posttraumatic tinnitus), or to delay neuronal death (neural presbycusis).
Biocompatibility of Hemodialysis Membranes: Interrelations between Plasma Complement and Cytokine Levels
Authors: Varela Maria P. , Kimmel Paul L. , Phillips Terry M. , Mishkin Gary J. , Lew Susie Q. , Bosch Juan P.
Published: April 2003

Hemodialysis (HD) membrane biocompatibility is defined as absence of complement activation. We have recently shown that circulating levels of interleukin (IL) 1 and IL-2 predict death and survival, respectively, of HD patients. Studies have assessed IL-1 in treatments with biocompatible and less biocompatible dialysis membranes, but no study has correlated circulating levels of all these immunoreactants. We assessed these immunoreactants, and temperature as an outcome, during HD in patients treated with different membranes. Twelve stable patients, receiving thrice-weekly chronic bicarbonate HD, were randomly dialyzed with three different types of membranes, composed of: Cuprophan, cuprammonium rayon modified cellulose, and Hemophan. Blood was drawn from the arterial line port before (Pre) and 15, 30, and 60 min during and after (Post) HD. Patients’ temperatures were measured before and after each treatment. The plasma concentrations of IL-1 and IL-2 and factors C3a and C5a were assessed by ELISA. There were no differences between baseline levels of any of the immunoreactants in patients treated with different dialyzers. C3a, C5a, and IL-1 levels increased significantly during HD treatments with all three different membranes. C3a, C5a, and IL-1 levels during Cuprophan and Hemophan treatments were significantly higher than the levels during modified cellulose treatment at 30 and 60 min and Post (p < 0.01). For all the immunoreactants, however, the Post levels were higher than the Pre levels. In contrast to IL-1, there were no differences in mean IL-2 levels during treatments when different membranes were compared. There were few correlations of plasma C3a and C5a levels with plasma IL-1 levels, but there was only one treatment time in one dialyzer group during which IL-2 and any of the other factors were correlated. Pre and Post temperature values and percent change in temperature were not correlated with any of the immunoreactants measured. These data show that C3a, C5a, and IL-1 responses are similar, but not identical, during treatments with different membranes. The response of circulating IL-2 levels to treatments is quite different from that of plasma C3a, C5a and IL-1 levels and suggests that these changes are not solely due to treatment factors. Treatment with modified cellulose membranes is associated with a different immunoreactive profile as compared with patients dialyzed using other cellulose membranes. We suggest that circulating IL-1 levels are good biocompatibility markers.
Blood Components Influence Cytokine Induction by Bacterial Substances
Authors: Schindler Ralf , Eichert Friedrich , Lepenies Julia , Frei Ulrich
Published: April 2003

While some studies clearly demonstrated transfer of cytokine-inducing substances (CIS) through dialysis membranes, other authors were unable to reproduce such a transfer. This inconsistency may have been caused by marked differences in experimental design. We performed a systematic evaluation of cytokine induction in whole blood and from separated peripheral blood mononuclear cells (PBMC) using either purified lipopolysaccharide (LPS) or culture supernatants from various bacterial strains. An in vitro hemodialysis circuit with whole blood in the blood compartment was employed; the dialysate was contaminated with sterile filtrates from Pseudomonas aeruginosa cultures. Addition of plasma samples from the blood side to PBMC readily induced interleukin (IL)-1β and IL-6 after contamination of the dialysate, while the same samples failed to induce cytokine production in whole blood. In experiments using direct incubation, purified P. aeruginosa LPS induced more IL-1β and IL-6 in whole blood compared to PBMC. In contrast, bacterial filtrates from Escherichia coli, Enterobacter cloacae and especially P. aeruginosa induced significantly less cytokines in whole blood compared to PBMC. Addition of erythrocytes but not granulocytes decreased cytokine induction by bacterial filtrates as well as by LPS, probably by adsorption of these substances. The addition of 30% plasma increased cytokine induction by LPS but decreased cytokine induction by P. aeruginosas filtrates. Our results suggest that cellular and plasmatic components of whole blood interact with bacterial CIS altering their pyrogenic activity. The detection of CIS depends on the test system used; whole blood cultures are not as sensitive for the detection of CIS from bacterial filtrates as PBMC cultures.
Catheter Design for Continuous Flow Peritoneal Dialysis
Authors: Ronco Claudio , Gloukhoff Angela , Dell’Aquila Roberto , Levin Nathan W.
Published: April 2003

A new catheter for continuous flow peritoneal dialysis is presented. One of the main issues in this field is the safety and good clinical tolerance of the catheter. In this case, the size and diameter of the cannula has not been increased in comparison to previous PD catheters. Furthermore, the materials utilized are designed for maximum comfort of the patient and minimal traumatisation of the peritoneal membrane. Nevertheless, the two compartments of the catheter allow for high dialysate flows without creating high resistance and the rate of recirculation is minimal in conditions of simulated continuous flow PD. Furthermore, the characteristic of the new catheter is the presence in the inflow branch of a special diffuser designed like a shower cap that is intended to improve the dialysate inflow distribution in the peritoneal cavity and to increase the contact of the peritoneal membrane with the solution. At the same time, the diffuser prevents a traumatic effect of the inflow dialysate due to high speed infusion or jet flow conditions.
Impact of the New K/DOQI Guidelines
Authors: Eknoyan Garabed , Levin Nathan W.
Published: April 2003

During the course of developing clinical practice guidelines to improve outcomes of dialysis patients, it became evident that there existed an even greater opportunity to improve outcomes for all individuals with kidney disease, from the earliest stage of kidney injury through the entire spectrum of its progression to kidney failure, when replacement therapy becomes necessary. The development and adoption of a public health approach to the progressive course of chronic kidney disease could allow for the application of interventional strategies to prevent the loss of kidney function in some cases, to slow the progression of kidney disease in many others, and to ameliorate the complication or comorbidities in those with progressive kidney disease. In order to respond to this need, a new initiative, termed the Kidney Disease Outcomes Quality Initiative (K/DOQI), was launched in January of 2000. This article summarizes the recommendations of the first three set of clinical practice guidelines being developed under this new initiative: Chronic Kidney Disease: Evaluation, Classification and Stratification; Bone Metabolism and Disease in Chronic Kidney Disease, and Dyslipidemias in Kidney Failure.
Nutritional Considerations in Renal Transplant Patients
Authors: van den Ham Eugénie C.H. , Kooman Jeroen P. , van Hooff Johannes P.
Published: April 2003

In renal transplant patients, weight gain generally increases after renal transplantation, which will be influenced by improved appetite and a reversal of the uremic state. However, at least in the early posttransplant period, the increase in body weight is mainly due to an increase in body fat mass. This phenomenon may be partly due to relatively high doses of steroids in the early period after renal transplantation, possibly mediated by their inhibiting effect on lipid peroxidation, but also appears to be related to physical inactivity. The increase in body fat mass may contribute to posttransplant hyperlipidemia, which is improved but not completely normalized by dietary intervention. Current dietary recommendations in stable renal transplant patients do not generally differ from those of the general population, although intense dietary counselling may be indicated in patients with excessive posttransplant weight gain. The effect of supervised exercise training on body composition is currently under investigation.
Clinical Outcome of Patients with Wegener’s Granulomatosis Treated with Plasma Exchange
Authors: Aasarød Knut , Iversen Bjarne M. , Hammerstrøm Jens , Bostad Leif , Jørstad Størker
Published: April 2003

We report the clinical course of 29 patients with Wegener’s granulomatosis (WG) treated with plasma exchange (PE) in Norway in the period from 1988 to 1999. Median follow-up was 41.5 months. The mean number of exchanges was 8.5 ± 5.8 (range 2–32). Median serum creatinine concentration was 400 µmol/l (range 90–1,356) and 17 patients were dialysis dependent at presentation. Two- and five-year patient survival was 75 and 71%, respectively, and renal (ESRD-free) survival was 74 and 54%, respectively. Seven (50%) of the 14 patients alive in the dialysis group had discontinued dialysis within the first month, and 6 (50%) of 12 patients alive at follow-up had independent renal function. No patients, however, had normal serum creatinine concentration. Median time until development of ESRD for patients presenting with a need for dialysis was ∼32 months. The development of ESRD in 79 patients treated with immunosuppression alone was significantly lower, but when adjusted for serum creatinine there was no difference between patients treated with or without PE. Although a considerable fraction of patients with WG and severe renal involvement regain independent renal function, few will have normal serum creatinine concentration at follow-up, despite the addition of PE as adjunctive therapy.
VLA-2 and VLA-5 Cell Adhesion Molecules Expression in CD34+ Cells from Umbilical Cord Blood and from Bone Marrow
Authors: Pafumi C. , Mancari R. , Parisi G. , Farina M. , Russo A. , Pernicone G. , Bandiera S. , Giardina P. , Mirisola T. , Stagno F. , Calogero A.E.
Published: April 2003

Background/Aims: Umbilical cord blood contains a large number of early hematopoietic cells with high proliferating capacity, that has been used as an alternative to bone marrow transplantation. The aim of this study is to investigate the number of two cell adhesion molecules in cord blood and in bone marrow. Methods: We investigated two integrins, named VLA-2 and VLA-5 (Very Late Appearing Antigen), expressed in the surface of CD34+ cells. The CD34+ cells, isolated with MACS CD34+ isolation kit, were labelled with the appropriate monoclonal antibodies. Results: Cell adhesion molecules showed highly expressed in both cord blood and bone marrow CD34+ cells. Conclusion: There are no significant differences between the two sources of CD34+ populations.
Vasopressors and the Kidney
Authors: Schetz Miet
Published: April 2003

The changes in renal perfusion induced by vasopressors depend on their effects on systemic hemodynamics and renal vascular resistance. Both effects are largely influenced by the patient’s underlying condition such as myocardial contractility and vascular responsiveness. A beneficial effect can be expected if mean arterial pressure increases without decreasing cardiac output and if the effect on renal vascular resistance is less pronounced than on systemic vascular resistance. Acute renal failure is associated with loss of renal autoregulation and sepsis is associated with blood pressures below the autoregulatory threshold. Both conditions might therefore benefit from the administration of vasopressors. Many experimental and clinical data indeed suggest a beneficial effect of norepinephrine on the urine output in sepsis. A beneficial effect on renal function (glomerular filtration) is a less consistent finding suggesting that pressure diuresis might be partially responsible for the pressor-induced diuresis. Administration of vasopressors to patients with oliguria should be considered in fluid-resuscitated patients with distributive shock. Whether other vasopressors offer advantages over norepinephrine requires further investigation.
Coupled Plasma Filtration Adsorption
Authors: Bellomo Rinaldo , Tetta Ciro , Brendolan Alessandra , Ronco Claudio
Published: April 2003

Both pro-inflammatory and anti-inflammatory mediators participate in the pathogenesis of sepsis and explain the failure of specific therapies to improve survival. Continuous extracorporeal therapies have been proposed as a therapeutic option in sepsis. We have studied the effects of plasma filtration associated with adsorption in patients with septic shock. We have shown that such treatment may lead to improved survival in a rabbit model of sepsis and to improved hemodynamics, reduced norepinephrine dose and restoration of near-to-normal responsiveness of blood leukocytes to endotoxin in humans. It is anticipated that treatment of plasma, as a device modular to conventional hemofiltration, may pave the way to innovative approaches to the extracorporeal treatment of septic patients.
Preeclampsia and Na,K-ATPase Activity of Red Blood Cell Ghosts from Neonatal and Maternal Blood
Authors: Carreiras Milagros M. , Proverbio Teresa , Proverbio Fulgencio , Marín Reinaldo
Published: April 2003

We determined Na,K-ATPase activity and cholesterol/phospholipid ratio of maternal and cord red blood cell ghosts from either normotensive or preeclamptic pregnant women. The Na,K-ATPase activity of the red cell ghosts from neonatal blood is significantly lower (25–32%) as compared with the ATPase activity of the maternal red cell ghosts, regardless of the presence or not of preeclampsia. This diminution in Na,K-ATPase activity of the neonatal red blood cell ghosts could be due to an increase in the cholesterol/phospholipid molar ratio of the membrane. The Na,K-ATPase activity of the red blood cell ghosts from pregnant women was unaffected by preeclampsia; however, fetal red blood cell ghosts from infants of preeclamptic mothers showed a significantly lower ATPase activity (20%) than fetal red blood cell ghosts from infants of normotensive mothers. A low Na,K-ATPase activity in the neonatal red blood cells from mothers with preeclampsia could be an indication of an important modification of the physiological role of this enzyme.
Postnatal Dexamethasone Treatment and Retinopathy of Prematurity in Very-Low-Birth-Weight Neonates
Authors: Cuculich Phillip S. , DeLozier Kellie A. , Mellen Beverly G. , Shenai Jayant P.
Published: April 2003

Whether postnatal dexamethasone treatment for bronchopulmonary dysplasia (BPD) increases the risk of retinopathy of prematurity (ROP) in very-low-birth-weight (VLBW) neonates is uncertain. We performed a retrospective cohort study to determine the association between dexamethasone administered postnatally and the development of ROP in VLBW (≤1,250 g birth weight, ≤32 weeks’ gestational age at birth) neonates. The incidence of severe ROP (stage 2 or higher) was 26% among 72 infants who received no dexamethasone postnatally, 61% among 23 infants who received a low cumulative dexamethasone dose (≤1.8 mg/kg body weight), and 85% among 20 infants who received a high cumulative dexamethasone dose (>1.8 mg/kg body weight). However, after adjustment for confounding covariates of prematurity and severity of lung disease by logistic regression analysis, we found no independent association between postnatal dexamethasone treatment and the incidence of severe ROP.
Single Breath Analysis of Endogenous Nitric Oxide in the Newborn
Authors: Artlich Andreas , Jónsson Baldvin , Bhiladvala Maneck , Lönnqvist Per Arne , Gustafsson Lars E.
Published: April 2003

Nitric oxide (NO) is found in the exhaled gas of humans immediately after birth. However, variations of endogenous NO concentration during the breathing cycle have not been studied in newborns. We examined 24 newborns without acute respiratory compromise during spontaneous nasal breathing. Gas was sampled from the tip of a thin nasal catheter placed in the hypopharynx. Endogenous NO concentrations measured by chemiluminescence were assigned to the breathing cycle using synchronized CO2 recording. Exhaled NO could reproducibly be measured at 1.9 ± 0.2 parts per billion (ppb, mean ± SEM). Autoinhaled nasal NO peaks during regular breathing were 12.0 ± 1.7 ppb and reached intermittent maxima of 52.2 ± 5.8 ppb. During regular breathing 6 infants exhibited sudden decreases of nasal NO peaks to periods with <50% amplitude suggesting transient shortage of autoinhaled nasal NO. We conclude that tidal NO analysis can be used to assess upper and lower airway NO production noninvasively during spontaneous breathing in the newborn.
Generation of Periventricular Leukomalacia by Repeated Umbilical Cord Occlusion in Near-Term Fetal Sheep and Its Possible Pathogenetical Mechanisms
Authors: Marumo G. , Kozuma S. , Ohyu J. , Hamai Y. , Machida Y. , Kobayashi K. , Ryo E. , Unno N. , Fujii T. , Baba K. , Okai T. , Takashima S. , Taketani Y.
Published: April 2003

Periventricular leukomalacia (PVL) is a major cause of cerebral palsy. However, pathogenetic mechanisms of PVL have not been fully understood. Although it has been postulated that umbilical cord compression is related to the development of PVL, no animal experiments clearly demonstrated an association of umbilical cord occlusion with ‘periventricular’ white matter lesions. The purpose of this study is to determine whether umbilical cord occlusions could produce periventricular white matter lesions in fetal sheep and to examine how changes in fetal cardiovascular and metabolic variables are related to the induction of brain damage. Fourteen near-term fetal sheep underwent umbilical cord occlusion (3-min total cord occlusions 5 times at 5-min intervals). Dissections performed 24 h after cord occlusion revealed that periventricular white matter lesions were produced in 7 out of 14 sheep fetuses. According to the pattern of brain damage, we classified the fetal sheep into three groups: 5 fetuses with dominant lesions in the periventricular white matter (group I), 4 fetuses with brain lesions in the cerebral cortex and thalamus (group II) and 5 fetuses with no or minimal brain lesions (group III). Group I showed higher blood pressure and higher plasma lipid peroxide levels before cord occlusion compared to the other groups, while group II showed systemic hypotension during cord occlusion. No significant differences in changes in pH, PaCO2, PaO2 and heart rate were found between the three groups. It is speculated that PVL might be produced by an association of preexisting chronic circulatory instability with an acute episode of severe repetitive cord occlusion.
Brain Water and Proton Magnetic Resonance Relaxation in Preterm and Term Rabbit Pups: Their Relation to Tissue Hyaluronan
Authors: Sulyok Endre , Nyúl Zoltán , Bogner Péter , Berényi Ervin , Repa Imre , Vajda Zsolt , Dóczi Tamás , Sedin Gunnar
Published: April 2003

The present study was performed to investigate simultaneously total brain water, T1 and T2 relaxation times, and hyaluronan (HA) in fetal and neonatal rabbits. Attempts were also made to establish the relationship of HA to total brain water and to T2-derived motionally distinct water fractions, since HA is known to bind water and to limit tissue water mobility. Experiments were carried out in fetal Pannon white rabbit pups at gestational ages of 25, 27, 29, and 31 days and at a postnatal age of 4 days. The brain tissue water content (desiccation method), T1 and T2 relaxation times (H1-NMR method), and HA concentration (radioassay HA 50) were measured, and free and bound water fractions were calculated by using multicomponent fits of the T2 relaxation curves. Compared with values in newborn pups, water and HA contents were found to be highly elevated in the preterm brain and decreased markedly during early postnatal life. The trends and time courses of T1 and T2 relaxation times proved to be similar, but the postnatal decrease in T2 was preceded by a significant decline in late gestation. Maturity-related changes occurred in the T2 relaxation derived bound water fraction which amounted to 4–19% of brain water. The bound water fraction appeared to be independent of total brain water and HA concentration, and HA is, therefore, unlikely to be the only factor controlling brain water mobility. The clear dissociation of bound water fraction from total water suggests restructuring of brain water during the perinatal period.
Perinatal Expression of Heat-Shock Protein 90 in Different Regions of the Brain and in Non-Neural Tissues of the Piglet
Authors: David Jean Claude , Grongnet Jean François
Published: April 2003

Important stressful events occur at birth or within the few hours that follow. To establish a possible involvement of stress proteins, expression of heat-shock protein 90 was determined by Western blotting in several regions of the brain and in non-neural tissues of the developing piglet (fetal to 10 days and adult). Expression was found in all the tissues studied. While comparable values were found in the whole brain during development, decreased expressions were observed from 4 to 8 h to 2 days after birth in cerebellum, cortex, hypothalamus and striatum. In hippocampus, low expression was observed from 4 h postnatally onward. In non-neural tissues, low expression was observed after birth and in the adult for heart, liver and lungs. In kidney, low values were found from birth to 1 day of age. Changes in environmental parameters like temperature and/or hypoxia can be related to differential expressions of heat-shock proteins and they possibly result in severe developmental outcomes. The results are discussed in terms of using the newborn piglet as a model for the study of different forms of stress on the heat-shock protein expression during postnatal development.
Sensorial Saturation: An Effective Analgesic Tool for Heel-Prick in Preterm Infants
Authors: Bellieni C.V. , Buonocore G. , Nenci A. , Franci N. , Cordelli D.M. , Bagnoli F.
Published: April 2003

Pain is traumatic for preterm infants and can damage their CNS. We wanted to assess whether multisensorial stimulation can be analgesic and whether this effect is only due to oral glucose or sucking. We performed a randomized prospective study, using a validated acute pain rating scale to assess pain during heel-prick combined with five different procedures: (A) control, (B) 10% oral glucose plus sucking, (C) sensorial saturation (SS), (D) oral water, and (E) 10% oral glucose. SS is a multisensorial stimulation consisting of delicate tactile, vestibular, gustative, olfactory, auditory and visual stimuli. Controls did not receive any analgesia. We studied 85 heel-pricks (5 per baby) performed for routine blood samples in 17 preterm infants (28–35 weeks of gestational age). We applied in random order in each patient the five procedures described above and scored pain. SS and sucking plus oral glucose have the greater analgesic effect with respect to no intervention (p < 0.001). The effect of SS is statistically better than that of glucose plus sucking (p < 0.01). SS promotes interaction between nurse and infant and is a simple effective form of analgesia for the NICU.
Fetal Bile Acid Metabolism: Analysis of Urinary 3β-Monohydroxy-Δ5 Bile Acid in Preterm Infants
Authors: Yamato Yasuhiko , Kimura Akihiko , Inoue Toshiro , Kurosawa Takao , Kato Hirohisa
Published: April 2003

To elucidate the urinary concentration of total bile acids after birth and the profile of the usual and unusual urinary bile acids, especially 3β-hydroxy-5-cholen-24-oic acid (Δ5-3β-ol), we measured the concentrations of 13 bile acids in the urine from preterm infants vs. full-term controls by gas chromatography-mass spectrometry. The urinary concentration of total bile acids in early preterm infants below 32 weeks of gestational age significantly exceeded that of the late preterm and full-term infants (p < 0.0005). The major urinary bile acids in early preterm infants were cholic acid, 1β,3α,7α,12α-tetrahydroxy-5β-cholan-24-oic acid and Δ5-3β-ol. In conclusion, the high urinary concentrations of total bile acids in preterm infants may be due to an overproduction, or more likely to a low hepatic bile acid clearance. An alternative fetal pathway, the acidic pathway, may be a major route of bile acid biosynthesis in preterm infants.
Changes in the G Gamma- and A Gamma-Globin mRNA Components of Fetal Hemoglobin during Human Development
Authors: Bard Harry , Peri Krishna G. , Gagnon Carmen
Published: April 2003

To determine the postnatal developmental changes in Gγ- and Aγ-globin mRNAs of HbF, blood samples were obtained from 28 pre-term infants born at ≤ 33 weeks of gestation (27.9 ± 2.5), 9 term-born infants and 26 adults. Adult samples were used to determine the relationship between the levels Gγ- and Aγ-mRNAs of HbF and the–158 (C→T) variation in the promoter region of the Gγ-globin gene. The results showed that Gγ-globin mRNA to total γ-globin mRNAs remained around 66% (66.2 ± 4) until the 44 week of postconceptual age when a change in the Gγ- and Aγ-globin mRNA proportions occurred. The immature red cells of adults had a range of Gγ-globin mRNA to total γ-globin mRNAs varying from 20 to 74% (53.1 ± 16.9). The high levels of Gγ-globin mRNA to total γ-globin mRNAs are associated with the presence of a –158 (C→T) polymorphism. The gene frequency of polymorphism was 0.32.
Prenatal Influence of Ischemia-Hypoxia-Induced Intrauterine Growth Retardation on Brain Development and Behavioral Activity in Rats
Authors: Tashima Lena , Nakata Masahiko , Anno Kikue , Sugino Norihiro , Kato Hiroshi
Published: April 2003

The effects of intrauterine growth retardation (IUGR) on brain histological or functional development were examined in rats. IUGR was induced by ligating the bilateral uterine arteries at day 17 of pregnancy. On day 22 of pregnancy, cesarean section was performed, and pups with a birth weight of <2 SD of the mean birth weight of control pups were regarded as IUGR rats. Morphological changes of the brain were studied by Nissl’s staining at different timepoints during prenatal and postnatal periods. For behavioral study, an open-field test was performed at 5, 7 and 10 weeks after birth. Histological studies showed the migration disorder of the neurons in the cerebral cortex from embryonic day 17 to postnatal day (PD) 49. The open-field test revealed locomotor disturbance at PD49 in male IUGR rats, but not in female IUGR rats or control rats. It is concluded that IUGR due to antenatal ischemia-hypoxia causes morphological changes in the central nervous system, and induces behavioral impairment, particularly in male rats.
Pre- and Postnatal Tissue Selenium of the Rat in the Growing State
Authors: Bou-Resli M.N. , Dashti H.M. , Mathew T.C. , Al-Zaid N.S.
Published: April 2003

The aim of this study is to quantify the selenium (Se) content (in µg/g) during different gestational periods in rat fetal tissues, and to follow up the changes in the Se content of the placenta, fetal head, liver and lung during gestation and postpartum periods. Locally reared virgin female Wistar rats were mated. Pregnant rats were sacrificed on days 15, 18 and 21 of pregnancy. Newborn pups at the age of 3 days and rats at the age of 1 month were also investigated. There was a gradual increase in placental and whole head Se content as gestation proceeded compared to day 15; however, the differences between the groups were not statistically significant. The liver Se content at day 18 of gestation was significantly higher than at day 21 of gestation and in rats at 3 days of age, but lower than the Se content of the liver of rats at the age of 1 month and the differences were statistically significant. The lung Se content was higher at day 18 of gestation than at day 21 and in the 3-day-old rats, and all differences between all groups were statistically significant except when the lung Se content at day 18 is compared to that of 1-month-old animals. The continuous increase in the Se content of the placental tissues and the whole head, although not significant statistically, may indicate that the fetus relies heavily on its supply of Se from the maternal blood and in part on the supply of thyroid hormones which are important for brain development, as evidence exists that T4 and T3 are present in the fetal brain in early fetal life before the onset of fetal thyroid function. The higher content of Se on day 18 and its decline on day 21 of gestation in the liver may imply that it is stored and being utilized partly in other tissues for other functions and particularly for thyroid hormone synthesis, metabolism and functions.
Surfactant Protein A and B Genetic Variants and Respiratory Distress Syndrome: Allele Interactions
Authors: Floros Joanna , Fan Ruzong
Published: April 2003

The contribution of multiple genetic components in disease pathogenesis is relevant to both diseases of multifactorial and/or multigenic etiology such as the respiratory distress syndrome (RDS) and to diseases where a single gene has been identified as the disease-causing gene. An example of the latter is cystic fibrosis (CF) where the disease-causing gene has been clearly identified as the CF transmembrane conductance regulator gene, but genetic variants of the mannose binding protein and surfactant protein A have been associated with disease severity in CF. The overall rationale for considering genetic contribution to disease pathogenesis is based on the premise that all diseases or deaths (except perhaps those resulting from trauma) have a genetic component. The difference in genetic contribution among various diseases is the percent contribution and the number of factors that make this contribution. Therefore, if the number of genetic contributors is small and the percentage of genetic contribution is high it may be less challenging to identify such factors. In this paper we summarize allele associations and discuss allele interaction of the surfactant protein genes in relation to RDS (the term allele and genetic variant will be used interchangeably).
A Low Serum sICAM-1 Level May Assist in the Exclusion of Neonatal Infection
Authors: Edgar David , Gabriel Vanessa , Craig Adam , Wheeler Darren , Thomas Moira , Grant Judith
Published: April 2003

Serum levels of soluble intercellular adhesion molecule-1 (sICAM-1) in 46 samples from 46 infants undergoing intensive care were studied. Residual serum remaining after routine electrolyte analysis was utilised. sICAM-1 levels were determined by ELISA. Blind retrospective chart review was employed to determine whether infants were infected. Serum levels were significantly elevated in infants with proven and probable infection, compared with non-infected infants (p < 0.001). sICAM-1 levels in serum were comparable to levels previously established in plasma samples. The results suggest that serum sICAM-1 measurement is a simple and robust test that differentiates infected from non-infected infants and that a low level of serum sICAM-1 may particularly assist in the exclusion of infection.
Estradiol Modulation of Central Monoamine Activity in Female Mountain Spiny Lizards
Authors: Woodley Sarah K. , Matt Kathleen S. , Moore Michael C.
Published: April 2003

Although estradiol (E2) mediates many behaviors in females, relatively little is known about its role in female aggression. Previous studies in female mountain spiny lizards indicated that female aggression is modulated by ovariectomy and sex steroid hormone replacement and that expression of aggressive behavior is accompanied by changes in serotonin activity. This study examines if E2 modulates the activity of serotonin and other central monoamines. Free-living females were caught and housed in the laboratory and received one of 3 treatments: sham surgery (SHAM), ovariectomy plus empty implant (OVEX), or sham surgery plus a long lasting E2 implant (E2-IMP). After 3 weeks of treatment, selected brain areas were examined for levels of monoamines and their metabolites. Changes in monoamine activity were most pronounced in the septum where levels of serotonin (5-HT), 5-hydroxyindoleacetic acid (5-HIAA), and norepinephrine (NE) were higher in E2-IMP females relative to SHAM, and levels of 5-HIAA were higher in OVEX females relative to SHAM. Changes in dopamine (DA) activity were also found, with increased DA concentration and decreased ratio of forebrain:brainstem HVA concentrations in E2-IMP relative to SHAM females. These results suggest that the actions of E2 on aggression might be mediated, in part, by dose-dependent effects on 5-HT activity in the septum.
Emergence of Axonal Tracts in the Developing Brain of the Turbot (Psetta maxima)
Authors: Doldán María Jesús , Prego Benjamín , Holmqvist Bo , Helvik Jon Vidar , de Miguel Encarnación
Published: April 2003

In this study we have investigated the pattern of morphogenesis and axogenesis in the turbot brain during embryonic and early larval stages with immunohistochemistry using an antibody against acetylated tubulin. The first immunoreactive elements were detected at 74 h post-fertilization in fibers running in the medial and lateral longitudinal fascicles. Newly positive axonal bundles are progressively added during development forming rostrocaudally directed tracts. The tract of the postoptic commissure appears at 86 h post-fertilization located rostrally to the medial longitudinal fascicle. Together, the medial longitudinal fascicle and the tract of the postoptic commissure constitute a major longitudinal axonal pathway, which is extended rostrally in embryos of 98 h post-fertilization by the supraoptic tract. In the forebrain, two vertical tracts, the tract of the posterior commissure (appearing around 98 h post-fertilization) and the tract of the anterior commissure (detected at 110 h post-fertilization) project descending axons to the pre-existing axonal longitudinal pathway. These early tracts are connected by four associated commissures (ventral tegmental, postoptic, posterior and anterior commissure). Some groups of labeled cell bodies are identified either as the origin of the embryonic tracts or contributing axons to the axonal pathways. Additionally, a conspicuous cluster of large cells, not clearly associated with any axonal bundle, was observed from 98 h post-fertilization lining the caudal floor of the presumptive hypothalamus. Several hypotheses are proposed to determine the nature of these cells. A comparison of the emergence of the axonal circuitry in turbot and that of other teleosts reveals significant analogies, suggesting that a common pattern underlies the establishment of the embryonic tracts in this vertebrate group. The minor differences observed between different teleost species, associated with the absence of some axonal fascicles, is also considered.
Brain Mediation of Anolis Social Dominance Displays
Authors: Baxter Jr. Lewis R. , Clark Edward C. , Ackermann Robert F. , Lacan Goran , Melega William P.
Published: April 2003

Serotonin (5-HT) functions are associated with social dominance status in diverse species, but to date the brain regions wherein 5-HT exerts such effects are uncertain. Here, we indexed 5-HT turnover in male Anolis carolinensis as the ratio of 5-HT to its metabolite, 5-hydroxy-indol-acetic acid, and also as the accumulation of the in vivo tracer 14C-alpha-methyl-tryptophan (14C-AMT). After patching one eye, displaying dominant animals increased both measures of 5-HT turnover in the forebrain hemisphere receiving display-evocative visual stimuli, compared to control, contralateral brain, whereas both 5-HT turnover indices were decreased when animals displayed submissively. In contrast, various non-displaying controls showed forebrain symmetry on both measures. Drugs that stimulate 5-HT2C receptors in mammals, and have 5-HT2C-like binding in A. carolinensis, evoked some elements of dominant display behaviors in non-dominant anole males and also activated dorsolateral basal ganglia as seen in non-medicated dominants when they display [Baxter et al., 2001]. Thus, acute changes in forebrain 5-HT output from baseline equilibrium, acting at 5-HT2C-like receptors, might effect some elements of the dominant vs. submissive male anoles’ territorial displays. A mechanistic model of how this might occur is offered. Given similarities in 5-HT systems, forebrain functions, and territorial display routines, similar mechanisms might have similar functions in other amniotes, including primates.
Pharmacological Characterization of the D1- and D2-Like Dopamine Receptors from the Brain of the Leopard Frog, Rana pipiens
Authors: Chua Joanne , Wilczynskia Walter , Wilcoxb Richard E.
Published: April 2003

The pharmacological profiles of D1- and D2-like dopamine receptors were investigated for native brain receptors in the leopard frog, Rana pipiens, using direct binding assays, which characterize functional receptors rather than assess total receptor protein. We used homogenate assays of R. pipiens fore- and midbrains to determine, via saturation isotherms, that the dissociation constant, Kd, for 3H-SCH-23390 binding to the D1-like receptors was 0.29 nM, and the maximal receptor density, Bmax, was 40 fmoles/mg protein. This compares with the more than 10-fold higher density of D1 sites in rat striatum. Specific binding for the D2-like receptors was measurable using these methods with 3H-spiperone as the ligand. However, saturation of binding was not achieved. This contrasts with the > 400 fmoles/mg protein Bmax in rat striatum. Pharmacological profiles (rank order of potency of displacing drugs) for each receptor type were determined. We used non-radioactive SCH-23390, SKF-38393, sulpiride, and spiperone to displace 3H-SCH-23390 and 3H-spiperone at D1 and D2 receptors, respectively. Parallel displacement assays were performed with rat striatal controls. Results indicated that the relative rank order displacements in anuran dopamine receptors were characteristic of D1- and D2-like receptors. However, the rank orders were not identical to those in mammals. The rank order for affinity at D1-like receptors in both rats and frogs was SCH-23390 > SKF-38393 > spiperone > sulpiride. The rank order for affinity at D2-like receptors was spiperone > SCH-23390 > sulpiride > SKF-38393 in frogs, and spiperone > sulpiride > SCH-23390 > SKF-38393 in rats. SKF-38393 and spiperone had similar affinities for the ‘D1’ receptors in both species. SCH-23390 had a slightly lower affinity for the D1-like receptors in Rana, whereas sulpiride had a significantly lower affinity for Rana D1-like receptors compared to rat D1 receptors. In Rana D2-like receptors, spiperone and sulpiride were significantly less potent compared to rat. However, SCH-23390 and SKF-38393 were equally potent for the D2-like receptors in both species. The results indicate that amphibian brain dopamine receptors fall into two classes similar to the mammalian D1 and D2 subfamilies, but with binding characteristics slightly different from those typically described in mammals. This work represents the first pharmacological characterization of native brain dopaminergic receptors in an anuran amphibian. Because direct binding assays measure the initial aspect of the functional interaction between transmitter and receptor, these data provide an important complement to studies using cell expression systems.
Ostrich Ocular Optics
Authors: Martin Graham R. , Ashash Udi , Katzir Gadi
Published: April 2003

The optical structure of the eyes of ostriches (Struthio camelus; Struthionidae; Struthioniformes) was determined by the construction of a schematic eye model for paraxial optics. The eye is large (axial length = 38 mm) and of globose shape with an anterior focal length (posterior nodal distance) of 21.8 mm. The optical design of the eye is such that the lens and cornea contribute equally to its total optical power. Interspecific comparison shows that optically the ostrich eye is a larger scaled version of the eyes of common starlings (Sturnus vulgaris) and an owl (Strix aluco).
NADPH-Diaphorase Activity and Nitric Oxide Synthase-Like Immunoreactivity Colocalize in the Electromotor System of Four Species of Gymnotiform Fish
Authors: Smith G. Troy , Unguez Graciela A. , Reinauer Jr. Robert M.
Published: April 2003

The electric organ discharge (EOD) of gymnotiform electric fish is controlled by a well-characterized neural circuit in the brainstem and spinal cord. NADPH-diaphorase (NADPH-d) activity was previously found in phase-locking and/or rapidly firing neurons in the electromotor and electrosensory systems of Apteronotus leptorhynchus [Turner and Moroz, 1995]. These findings suggested that nitric oxide synthase (NOS) is expressed in these neurons and may regulate their precise, high frequency firing. We extended these results by examining the distribution of both NADPH-d activity and NOS-like immunoreactivity (NOS-lir) in the electromotor systems of four gymnotiform species that differ in the frequency and modulation of their EODs. NOS-lir colocalized with NADPH-d staining throughout the electromotor system, indicating that NADPH-d is a faithful indicator of NOS in this system. The distribution of NOS-lir and NADPH-d was similar in the electromotor systems of all four species in this study, with one exception: NOS and NADPH-d staining was consistently less intense in pacemaker and relay cells in Sternopygus macrurus, which produces low frequency EODs, than in the three other species that produce higher frequency EODs. This species difference in NOS expression in the pacemaker nucleus may be related to species differences either in EOD frequency or in modulations of the EOD (e.g., the jamming avoidance response). In Apteronotus species, NOS-lir and NADPH-d were concentrated in bands along the axons of their nerve-derived electric organs. These bands corresponded to regions surrounded by little or no staining with a Schwann cell-specific antibody, suggesting that the NOS-positive regions lie near nodes of Ranvier. In Sternopygus and Eigenmannia, the innervated, posterior membranes of muscle-derived electrocytes were more intensely labeled for NADPH-d and NOS than inexcitable portions of the membrane. Thus, in both muscle- and nerve-derived electric organs, NOS is concentrated near excitable membranes. These results indicate that NOS is well-positioned within the electromotor system to regulate the frequency, precision, amplitude, and waveform of EODs.
The Change of DMFT Counts in Slovenia
Authors: Kovač-Kavčič M. , Skalerič U.
Published: April 2003

This longitudinal study was designed to assess the change in caries prevalence and DMFT counts in the adult population of Ljubljana, Slovenia, over a 10–year period. All data in the present study are derived from two surveys conducted in 1983–1987 and 1993–1997. In the first survey, 1,609 dentate subjects in the range from 15 to 65 years were examined. Ten years later, 555 (34.5%) of these subjects participated in the second oral survey. In the 538 dentate 25– to 75–year–old subjects examined in the second survey, a decline in the mean number of decayed teeth (1.1 vs. 0.5) was found, and an increase in DMFT counts (15.9 vs. 19.1) due to a higher number of missing (5.2 vs. 7.5) and filled teeth (9.7 vs. 11.1) was observed. However, a comparison with the previous generation of the same age showed a decline in the average number of decayed and missing teeth in all age groups and an increase in the mean number of filled teeth in all age groups as well. The population of Ljubljana from the 1993–1997 survey had retained in most of the age groups about 2 teeth more than had the generation 10 years before.
Comparison between Visual Examination and a Laser Fluorescence System for in vivo Diagnosis of Occlusal Caries
Authors: Sheehy E.C. , Brailsford S.R. , Kidd E.A.M. , Beighton D. , Zoitopoulos L.
Published: April 2003

This study compared a laser fluorescence (LF) system (DIAGNOdent) with a visual caries scoring system for in vivo detection and diagnosis of occlusal caries under the conditions of an epidemiological study, in 132 mandibular and 38 maxillary first permanent molars in 170 children (mean age: 6.85 ± 0.58 years). The teeth were cleaned and occlusal caries status in a selected investigation site recorded using both visual and LF systems. The LF readings were interpreted both according to the cut–off points recommended by the manufacturers and those based on laboratory research with histological validation. The percentage agreement of the LF and visual scoring system was better using the cut–off limits recommended by the manufacturer. Histological validation was not possible in this clinical study, but it appeared that either the LF method was overscoring some lesions or the visual method was underscoring them. Since the LF instrument cannot be expected to differentiate caries from hypomineralisation, it should probably be used as an adjunct to a clinical examination.