Phosphate complexation model and its implications for chemical phosphorus removal

A phosphate complexation model is developed, in an attempt to understand the mechanistic basis of chemically mediated phosphate removal. The model presented here is based on geochemical reaction modeling techniques and uses known surface reactions possible on hydrous ferric oxide (HFO). The types of surface reactions and their reaction stoichiometry and binding energies (logK values) are taken from literature models of phosphate interactions with iron oxides. The most important modeling parameter is the proportionality of converting moles of precipitated HFO to reactive site density. For well-mixed systems and phosphate exposed to ferric chloride during HFO precipitation, there is a phosphate capacity of 1.18 phosphate ions per iron atom. In poorly mixed systems with phosphate exposed to iron after HFO formation, the capacity decreased to 25% of the well-mixed value. The same surface complexation model can describe multiple data sets, by varying only a single parameter proportional to the availability of reactive oxygen functional groups. This reflects the unavailability of reactive oxygen groups to bind phosphate. Electron microscope images and dye adsorption experiments demonstrate changes in reactive surface area with aging of HFO particles. Engineering implications of the model/mechanism are highlighted.

Pulse wave velocity in end-stage renal disease: influence of age and body dimensions

Arterial stiffness increases with age. This process is accelerated by end-stage renal disease (ESRD). Pulse wave velocity (PWV) increases with arterial stiffness. In this study, PWV of 133 healthy individuals (6-23 y of age) and 11 patients on dialysis was measured to establish the normal values of PWV and to compare them with those in ESRD. Age-matched (A-C) and height- and weight-matched (H/W-C) control groups were used. Thereafter, PWV was indexed to height and the data were reevaluated. The role of the risk factors including serum calcium, phosphate, parathyroid hormone (PTH), and the time on dialysis was analyzed using a score system. PWV correlated with age, weight, height, blood pressure, and heart rate. ESRD patients were smaller than A-C and older than H/W-C. PWV of patients with ESRD did not differ from A-C; however, it was elevated in comparison to H/W-C. In both healthy and ESRD patients, the PWV/height ratio was independent of age. PWV/height was increased in ESRD. There was a correlation between PWV/height and the risk factor score. Controls matched for height and weight or PWV/height should be used in cases of growth failure. A number of risk factors responsible for increased arterial stiffness are present in ESRD.

Transplantation of embryonic neurones to replace missing spinal motoneurones

Loss of spinal motoneurones results in severe functional impairment. The most successful way to replace missing motoneurones is the use of embryonic postmitotic motoneurone grafts. It has been shown that grafted motoneurones survive, differentiate and integrate into the host cord. If grafted motoneurones are provided with a suitable conduit for axonal regeneration (e.g. a reimplanted ventral root) the grafted cells are able to grow their axons along the whole length of the peripheral nerves to reach muscles in the limb and restore function. Grafted motoneurones show excellent survival in motoneurone-depleted adult host cords, but the developing spinal cord appears to be an unfavourable environment for these cells. The long term survival and maturation of the grafted neurones are dependent on the availability of a nerve conduit and one or more target muscles, no matter whether these are ectopic nerve-muscle implants or limb muscles in their original place. Thus, grafted and host motoneurones induce functional recovery of the denervated limb muscles when their axons regenerate into an avulsed and reimplanted ventral root. On the other hand, motoneurone-enriched embryonic grafts placed into a hemisection cavity in the cervical spinal cord induce axonal regeneration from great numbers of host motoneurones, possibly by the bridging effect of the grafts. In this case the regenerating host motoneurones reinnervate their original target muscles while the graft provides few axons for the reinnervation of muscles. These results suggest that reconstruction of the injured spinal cord with embryonic motoneurone-enriched spinal cord graft is a feasible method to improve severe functional motor deficits.

Clinicochemical follow-up of broiler rearing--a five-week study

Commercial broilers were raised in a 5-week period and a detailed clinicochemical follow-up was carried out, to characterise a flock selected for one-sided muscle mass production. Blood samples were drawn at the ages of 1 day, 1, 2, 3, 4 and 5 weeks, and plasma enzyme activities, metabolite and ion concentrations were determined. Early increases were found for all plasma nitrogenous compounds (total protein, albumin, creatinine and urate). Triglyceride showed a posthatch peak with a significant effect of age. Plasma total cholesterol was characterised by a marked post-hatch concentration peak, while during the first week its concentration decreased markedly. Plasma AST showed an increase during the rearing, while a one-magnitude increment was found for creatine kinase activity during the study. The main results of the study outlined a typical precocial bird (post-hatch triglyceride peak; decreasing cholesterol and early peaking plasma protein and urate concentrations) with very quick skeletal muscle mass growth (increasing creatine kinase and AST activities, slight hyperkalaemia).

Effects of articaine on action potential characteristics and the underlying ion currents in canine ventricular myocytes

BACKGROUND

In spite of its widespread clinical application, there is little information on the cellular cardiac effects of articaine. In the present study, the concentration-dependent effects of articaine on action potential morphology and the underlying ion currents were studied in isolated canine ventricular cardiomyocytes.

METHODS

Action potentials were recorded from the enzymatically dispersed myocytes using sharp microelectrodes (16 cells from 3 dogs). Conventional patch clamp and action potential voltage clamp arrangements were used to study the effects of articaine on transmembrane ion currents (37 cells from 14 dogs).

RESULTS

Articaine-induced concentration-dependent changes in action potential configuration including shortening of the action potentials, reduction of their amplitude and maximum velocity of depolarization (V(max)), suppression of early repolarization and depression of plateau. The EC50 value obtained for the V(max) block was 162 (sd 30) microM. Both the reduction of V(max) and action potential shortening were frequency dependent: the former was more prominent at shorter, while the latter at longer pacing cycle lengths. A rate dependent V(max) block, having rapid offset kinetics [tau = 91 (20) ms], was observed in addition to tonic block. Under voltage clamp conditions, a variety of ion currents were blocked by articaine: I(Ca) [EC50 = 471 (75) microM], I(to) [EC50 = 365 (62) microM], I(K1) [EC50 = 372 (46) microM], I(Kr) [EC50 = 278 (79) microM], and I(Ks) [EC50 = 326 (65) microM]. Hill coefficients were close to unity indicating a single binding site for articaine, except for I(K1).

CONCLUSIONS

Articaine can modify cardiac action potentials and ion currents at concentrations higher than the therapeutic range which can be achieved only by accidental venous injection. Since its suppressive effects on the inward and outward currents are relatively well balanced, the articaine-induced changes in action potential morphology may be moderate even in the case of overdose.

Characterization of Staphylococcus aureus strains isolated from bovine milk in Hungary

Staphylococcus aureus is a major foodborne pathogen due to its capability to produce a wide range of heat-stable enterotoxins. The primary purpose of this research was to characterize S. aureus isolates recovered from mammary quarter milk of mastitic cows and from bulk tank milk produced on Hungarian dairy farms of different sizes. Macrorestriction analysis of chromosomal DNA from S. aureus isolates was performed using the restriction enzyme SmaI followed by pulsed-field gel electrophoresis (PFGE). The prevalence rates of nine S. aureus enterotoxin genes (sea, seb, sec, sed, see, seg, seh, sei, and sej) and of the toxic shock syndrome toxin 1 gene (tst) were determined by multiplex polymerase chain reaction (PCR). The bulk tank milks of 14 out of 20 farms were contaminated with S. aureus at levels of up to 6.0x10(3 )CFU/ml. Farm size had no significant effect (P>0.05) on the S. aureus counts in bulk milk. The prevalence rates of penicillin resistance were 88.9% and 20.0% among the S. aureus recovered from mastitic quarter milk and bulk tank milk, respectively. After phenotypic characterization, a total of 59 S. aureus isolates were selected for genotyping. PFGE analysis revealed 22 distinct pulsotypes, including 14 main types and 8 subtypes, at a similarity level of 86%. Only one or two main types were observed on each of the farms tested, indicating a lack of genetic diversity among S. aureus isolates within farms, and there were only two pulsotypes which occurred on more than one farm. The PFGE patterns showed genetic relatedness between the S. aureus strains recovered from quarter milk and bulk milk on two large farms, implying that on farms having a high number of mastitic cows, S. aureus from infected udders may contaminate bulk milk and, subsequently, raw milk products. Sixteen (27.1%) of the S. aureus isolates tested by multiplex PCR were found to be positive for enterotoxin genes, with 15 of them carrying just one gene and one strain carrying two genes (seg and sei). The most commonly detected toxin genes were seb, sea, and sec, whereas none of our isolates possessed the see, seh, sej, or tst genes. On 75% of the dairy farms surveyed, no enterotoxigenic staphylococci were recovered from either mastitic quarter milk or bulk tank milk.

RNA expression as a prognostic tool in idiopathic nephrotic syndrome

A gyermekkori nephrosis 90%-a idiopathiás nephrosis szindróma. Az idetartozó három kórkép, a minimal change betegség, a mesangialis proliferatio és a focalis sclerosis hasonló klinikai képpel jelentkező, eltérő prognózisú és terápiás válaszú betegség. Dolgozatunk célja az idiopathiás nephrosis szindrómába tartozó kórképek kialakulásával, progressziójával összefüggő genetikai ismeretek, génexpressziós változások áttekintése és funkcionális csoportosítása. A génexpressziós változások meghatározásának eszközeként, dolgozatunk röviden összefoglalja a northern blot, a ribonuclease protection assay, azin situRNS-hibridizáció, a kvantitatív RT-PCR és a microarray módszerek lényegét. Az eddig elvégzett vizsgálatok a DNS-szintézis és repair gének, növekedési faktorok, extracelluláris mátrix, extracelluláris ligandreceptorok, extracelluláris jelátvitel zavarai mellett kiemelik a metabolikus és transzporter gének, illetve az immunszabályozó gének molekuláris eltéréseit, amelyek összefüggésben vannak az idiopathiás nephrosis szindróma eddig megismert molekuláris hátterével. A chiptechnológia fejlődésével és elterjedésével ezek a markerek és a hagyományos vizsgálati módszerek párhuzamos alkalmazása rutindiagnosztikai szempontból is fontossá válhat.

Delayed riluzole treatment is able to rescue injured rat spinal motoneurons

The effect of delayed 2-amino-6-trifluoromethoxy-benzothiazole (riluzole) treatment on injured motoneurons was studied. The L4 ventral root of adult rats was avulsed and reimplanted into the spinal cord. Immediately after the operation or with a delay of 5, 10, 14 or 16 days animals were treated with riluzole (n=5 in each group) while another four animals remained untreated. Three months after the operation the fluorescent dye Fast Blue was applied to the proximal end of the cut ventral ramus of the L4 spinal nerve to retrogradely label reinnervating neurons. Three days later the spinal cords were processed for counting the retrogradely labeled cells and choline acetyltransferase immunohistochemistry was performed to reveal the cholinergic cells in the spinal cords. In untreated animals there were 20.4+/-1.6 (+/-S.E.M.) retrogradely labeled neurons while in animals treated with riluzole immediately or 5 and 10 days after ventral root avulsion the number of labeled motoneurons ranged between 763+/-36 and 815+/-50 (S.E.M.). Riluzole treatment starting at 14 and 16 days after injury resulted in significantly lower number of reinnervating motoneurons (67+/-4 and 52+/-3 S.E.M., respectively). Thus, riluzole dramatically enhanced the survival and reinnervating capacity of injured motoneurons not only when treatment started immediately after injury but also in cases when riluzole treatment was delayed for up to 10 days. These results suggest that motoneurons destined to die after ventral root avulsion are programmed to survive for some time after injury and riluzole is able to rescue them during this period of time.

Genetic polymorphisms for vascular endothelial growth factor in perinatal complications

Low birth weight (LBW) infants have increased susceptibility to perinatal complications. An immature and impaired vascular system may possibly participate in these complications. There is evidence that supports the notion that vascular endothelial growth factor (VEGF), which is an essential regulator of embryonic angiogenesis, plays a central role in the pathogenesis of perinatal complications. We aimed to test whether functional genetic polymorphisms of VEGF are associated with the risk of preterm birth or perinatal morbidity. We enrolled 128 LBW infants (< or = 1500 grams). VEGF T-460C, VEGF C-2578A and VEGF G+405C polymorphisms were determined by real-time PCR or PCR-RFLP, respectively. Their genotypes were compared with VEGF genotypes of 200 healthy, term neonates. The prevalence of the VEGF+405 C allele was higher in LBW infants than in healthy, term neonates (OR [95% CI]: 1.29 [1.01-1.65]). Carrier state for the VEGF -2578A allele was an independent risk factor for enterocolitis necrotisans (NEC) (adjusted OR [95% CI]: 2.77 [1.00-7.65]). The carrier state for the VEGF -2578AA genotype was associated with a decreased risk of acute renal failure (ARF) (adjusted OR [95% CI]: 0.2 [0.05-0.78]). These results suggest that VEGF G+405C polymorphism might be associated with a higher risk of preterm birth and that VEGF C-2578A polymorphism may participate in the development of perinatal complications such as NEC and ARF.

Criminal liability of physicians and other health care professionals in Hungary (review of case law between 1996-2000)

The authors examine the criminal cases involving physicians and other health care workers between January 1996 and December 2000 inclusive. in Hungary. The data are based on the registry of the Criminal Prosecutor's Office. Altogether 94 cases were initiated in this period of time, the accused of the criminal proceeding was a registered nurse in 9 cases, an ambulance paramedic in 5 cases, a pharmacist in 3, and a physician in 77 cases. In cases where registered nurses were involved, the most common act was negligent change of medication or providing inadequate custody of a patient in need, pharmacists were also accused for negligent change of medicinal products. In case of ambulance assistants the most common violation of the professional rules was diagnostic failure or not responding to the call in time. As to physicians, mostly primary care physicians were accused (29%), usually for failing to examine the patient or for diagnostic error, obstetricians-gynecologists (17 %) and traumatologists (12 %) were also frequently accused.

Genetic polymorphisms of vascular endothelial growth factor and angiopoietin 2 in retinopathy of prematurity

Angiogenic factors such as vascular endothelial growth factor (VEGF) and angiopoietin 2 (Ang2) contribute to development of retinopathy of prematurity (ROP). We aimed to test whether polymorphisms of these factors are associated with ROP. VEGF(-2578) and Ang2(-35) polymorphisms were analyzed with PCR-RFLP method in 200 preterm infants without ROP or with ROP stages 1-5. Our results suggest that there is no association between carrier state of VEGF(-2578) and Ang2(-35) and risk of ROP in preterm infants. The prevalence of VEGF(-2578) "A" allele was lower in preterm boys with severe ROP (stages 4-5) than in those without or with mild ROP (stages 1-3).

The slow Wallerian degeneration genein vivoprotects motor axons but not their cell bodies after avulsion and neonatal axotomy

The slow Wallerian degeneration gene (Wld(S)) delays Wallerian degeneration and axon pathology for several weeks in mice and rats. Interestingly, neuronal cell death is also delayed in some in vivo models, most strikingly in the progressive motoneuronopathy mouse. Here, we tested the hypothesis that Wld(S) has a direct protective effect on motoneurone cell bodies in vivo. Cell death was induced in rat L4 motoneurones by intravertebral avulsion of the corresponding ventral roots. This simultaneously removed most of the motor axon, minimizing the possibility that the protective effect toward axons could rescue cell bodies secondarily. There was no significant difference between the survival of motoneurones in control and Wld(S) rats, suggesting that the Wld(S) gene has no direct protective effect on cell bodies. We also tested for any delay in apoptotic motoneurone death following neonatal nerve injury in Wld(S) rats and found that, unlike Wld(S) mice, Wld(S) rats show no delay in cell death. However, the corresponding distal axons were preserved, confirming that motoneurone cell bodies and motor axons die by different mechanisms. Thus, Wld(S) does not directly prevent death of motoneurone cell bodies. It follows that the protection of neuronal cell bodies observed in several disease and injury models where axons or significant axonal stumps remain is most probably secondary to axonal protection.

Effects of the somatostatin receptor subtype 4 selective agonist J-2156 on sensory neuropeptide release and inflammatory reactions in rodents

BACKGROUND AND PURPOSE

Substance P (SP) and calcitonin gene-related peptide (CGRP) released from capsaicin-sensitive sensory nerves induce local neurogenic inflammation; somatostatin exerts systemic anti-inflammatory actions presumably via sst4/sst1 receptors. This study investigates the effects of a high affinity, sst4-selective, synthetic agonist, J-2156, on sensory neuropeptide release in vitro and inflammatory processes in vivo.

EXPERIMENTAL APPROACH

Electrically-induced SP, CGRP and somatostatin release from isolated rat tracheae was measured with radioimmunoassay. Mustard oil-induced neurogenic inflammation in rat hindpaw skin was determined by Evans blue leakage and in the mouse ear with micrometry. Dextran-, carrageenan- or bradykinin-induced non-neurogenic inflammation was examined with plethysmometry or Evans blue, respectively. Adjuvant-induced chronic arthritis was assessed by plethysmometry and histological scoring. Granulocyte accumulation was determined with myeloperoxidase assay and IL-1beta with ELISA.

KEY RESULTS

J-2156 (10-2000 nM) diminished electrically-evoked neuropeptide release in a concentration-dependent manner. EC50 for the inhibition of substance P, CGRP and somatostatin release were 11.6 nM, 14.3 nM and 110.7 nM, respectively. J-2156 (1-100 microg kg(-1) i.p.) significantly, but not dose-dependently, inhibited neurogenic and non-neurogenic acute inflammatory processes and adjuvant-induced chronic oedema and arthritic changes. Endotoxin-evoked myeloperoxidase activity and IL-1beta production in the lung, but not IL-1beta- or zymosan-induced leukocyte accumulation in the skin were significantly diminished by J-2156.

CONCLUSIONS AND IMPLICATIONS

J-2156 acting on sst4 receptors inhibits neuropeptide release, vascular components of acute inflammatory processes, endotoxin-induced granulocyte accumulation and IL-1beta synthesis in the lung and synovial and inflammatory cells in chronic arthritis. Therefore it might be a promising lead for the development of novel anti-inflammatory drugs.

Effect of pituitary adenylate cyclase activating polypeptide-38 on sensory neuropeptide release and neurogenic inflammation in rats and mice

Substance P (SP) and calcitonin gene-related peptide (CGRP), released from capsaicin-sensitive sensory nerves induce local neurogenic inflammation, while somatostatin exerts systemic anti-inflammatory actions. The aim of the present study was to investigate the release of pituitary adenylate cyclase activating polypeptide-38 (PACAP-38) and its effects on sensory neuropeptide release in vitro and acute neurogenic ear swelling in vivo. Capsaicin (10(-6) M) or electrical field stimulation (EFS; 40 V, 0.1 ms, 10 Hz, 120 s; 1200 impulses)-induced release of PACAP-38, SP, CGRP and somatostatin from isolated rat tracheae was measured with radioimmunoassay. Mustard oil-induced neurogenic inflammation in the mouse ear was determined with a micrometer and in the rat hind paw skin by the Evans Blue leakage technique. Capsaicin and EFS evoked 27% and more than twofold elevation of PACAP-38 release respectively, compared with the prestimulated basal values from isolated trachea preparation. Exogenously administered PACAP-38 (20-2000 nM) diminished both capsaicin- and EFS-evoked sensory neuropeptide release in a concentration-dependent manner. The maximal inhibitory effects of PACAP on capsaicin-induced substance P, CGRP and somatostatin release amounted to 75.4%, 73.3% and 90.0%, while EFS-evoked release of these peptides was 80.03%, 87.7% and 67.7%. In case of capsaicin stimulation the EC50 values for substance P, CGRP and somatostatin were 82.9 nM, 60.1 nM and 66.9 nM, respectively. When EFS was performed, these corresponding EC50 data were 92.1 nM, 67.8 nM and 20.9 nM. PACAP-38 (10, 100 and 1000 microg/kg i.p. in 200 microl volume) inhibited neurogenic ear swelling in the mouse. Furthermore, 100 microg/kg i.p. PACAP also significantly diminished mustard oil-evoked plasma protein extravasation in the rat skin. These results suggest that PACAP-38 is released from the stimulated peripheral terminals of capsaicin-sensitive afferents and it is able to inhibit the outflow of sensory neuropeptides. Based on this mechanism of action PACAP is also able to effectively diminish/abolish neurogenic inflammatory response in vivo after systemic administration.

Ontogenic development of the fatty acyl chain composition of the turkey (Meleagris gallopavo) pectoralis superficialis muscle membranes: an allometric approach

The growth-associated development of the m. pectoralis superficialis (MPS) phospholipid (PL) and triacylglycerol (TAG) fatty acyl (FA) chain composition was determined in BUT8 meat-type turkeys. Samples (3 d, 8, 12, 16 and 20 wk) of each 6 males were analysed by lipid fractionation and subsequent gas chromatography. Results were interpreted on an allometric basis. The MPS mass increased linearly (MPS weight = 0.2787 BW- 123.67; R2 = 0.9935, P<0.001, n = 30). In the total phospholipids 62-63% unsaturated fatty acids were found irrespective of the diet. A negative allometric alteration was found for the total saturated acyl chains (B = -0.012), while a positive value for the calculated unsaturation index (B = 0.026) was obtained. Within the PUFA chains, the n3- n6 balance was markedly changed, on the favour of the n3 fatty acyl chains, namely competitive allometric trends were found for the total n3 (B = 0.087) and n6 (B = 0.032) fatty acid groups. The alterations of the TAG FA chain composition were diet-dependent. The serum creatine kinase activity increased by over one class of magnitude during the trial. The allometric approach was found to be powerful in the characterization of the basic, non diet-dependent ontogenic alterations of the phospholipid fatty acyl chain composition.

Body size related adaptations of the avian myocardial phospholipid fatty acyl chain composition

The myocardial phospholipid fatty acid (FA) composition (mol %) of 7 avian species was determined, in a body mass range from 150 g (Japanese quail, Coturnix coturnix japonica) to 19 kg (turkey, Meleagris gallopavo). Significant allometric increases were found for C16:1 n7 (allometric exponent: B=0.15), C18:1 n7 (B=0.08), C18:1 n9 (B=0.24), C20:1 n9 (B=0.22) and C20:3 n3 (B=0.12); moreover, total monounsaturates (B=0.20) and the sum of n9 FAs (B=0.24) was also positively related to body mass. The total n3 FAs (B=-0.36), and within them C22:5 n3 (B=-0.41) and C22:6 n3 (B=-0.60) showed allometric declines, such as total polyunsaturated fatty acids (PUFA; B=-0.01), unsaturation index (B=-0.03) and mean FA chain length (B=-0.003). Comparing our results with earlier published data on avian skeletal muscle and divergent mammalian tissues, the allometric scaling of the above membrane forming fatty acids seems to be part of a general relationship postulated as the theory "membranes as metabolic pacemakers". In addition, the cardiac muscle malondialdehyde concentration was negatively related to body mass (B=-0.16), referring to a lower level of lipid peroxidation in larger birds, and vice versa, indicating a progressive myocardial lipid peroxidation in smaller-bodied species.

Genetic polymorphisms of vascular endothelial growth factor in severe pre-eclampsia

Several lines of evidence support the hypothesis that vascular endothelial growth factor (VEGF) plays an important role in the pathogenesis of pre-eclampsia (PE). VEGF is a key component in the regulation of vascular remodelling and the survival of cytotrophoblasts in the placenta. In this case-control study, we aimed to test whether VEGF genetic polymorphisms are associated with the risk of severe PE. We enrolled 84 nulliparous pregnant women with severe PE (PE group). Their VEGF G(+405)C and VEGF C(-2578)A genotypes were determined by PCR-restriction fragment length polymorphism (PCR-RFLP) from venous blood samples and were compared with the corresponding VEGF genotypes of 96 nulliparous patients with uncomplicated pregnancies (control group). Carriers of the VEGF(+405)G allele occurred less frequently in PE than in the control group [P = 0.039; adjusted odds ratio (aOR) = 0.28, range: 0.08-0.93]. Hypertension and proteinuria were diagnosed earlier (by 1.6 weeks and 1.9 weeks, respectively) in PE patients with VEGF(-2578)A only after adjustment of this association for risk factors of PE. Our results suggest that carriers of VEGF(+405)G allele have a decreased susceptibility to PE and that the progression of PE may be modified by the presence of VEGF(-2578)A allele. Nevertheless, the clinical significance of these findings remains to be determined.

Development of a computed tomographic calibration method for the determination of lean meat content in pig carcasses

Sixty left sides of pig carcasses were scanned by spiral computed tomography (CT) to measure lean meat weight and percentage. The carcasses were fully dissected and scanned to develop a calibration protocol. Different image analyses were performed on the basis of anatomically defined scans, direct volumetric estimation, body- and grey-scale ranges and using Partial Least Squares (PLS) regression of data provided by CT. The R2 values of the calibrations for lean meat weight were 0.874, 0.976, 0.983 and 0.992, respectively, depending on the method applied. The PLS proved to be the best approach with a calibration RSD of 232 g. When changing from lean meat weight to percentage, the statistical goodness drops-to a very small extent (R2 = 0.988, RSD = 0.56). According to the results, the CT method can be recommended as a reference for determining the lean meat content of pig carcasses.

[Osteopenia of prematurity]

The survival rate of premature infants has been significantly increased during the last decades. As a consequence, the problem of less imminent, slowly progressing, but also important disorders such as osteopenia of prematurity has been emerging. The diagnosis of osteopenia of prematurity is based evidence for less bone mineral density compared to fetuses or infants at the same gestational age in the absence of laboratory parameters and/or clinical signs for rachitis or other metabolic bone disease. The incidence of osteopenia among infants born before 28 weeks of gestational age are as high as 30%. The aim of this paper is to review the information regarding the prevention and treatment of osteopenia of prematurity and to summarize the preventive measures to avoid fractures or bone deformations and to achieve the genetically determined peak bone mass. The latter is essential for the prevention of osteoporosis in adulthood, a significant problem of public health.

Association between interleukin-6 polymorphism and age-at-onset of type 1 diabetes. Epistatic influences of the tumor necrosis factor-alpha and interleukin-1beta polymorphisms

Multiple immune mediators have been mentioned as playing a role in the pathomechanism of type1 DM. Interleukin (IL)-1beta, and tumor necrosis factor (TNF)-alpha play a central role in the autoimmune destruction of pancreatic beta-cells, whereas IL-6 inhibits TNF-alpha secretion, and may have some protecting effects. In our study, we aimed to investigate the association between these three cytokines' single nucleotide polymorphisms (IL-6 gene G(-174)C, TNF-alpha gene G(-308)A and IL-1beta gene C(3954)T polymorphisms) and age-at-onset of type 1 diabetes mellitus (T1DM) in 165 diabetic children (median age: 17 years). Polymorphisms were determined using the PCR-RFLP method. We found that the age-at-onset of T1DM was significantly different in patients with a different IL-6 genotype (median age-at-onset of T1DM was: 8, 6 and 4.5 years in children with the (-174)GG, GC and CC genotypes, respectively; p < 0.01). Adjusted for TNF-alpha and IL-1beta polymorphisms, patients with a IL-6 (-174)CC genotype have a 3.0-fold (95% CI: 1.2-7.1) increased risk of developing diabetes before the age of 6 years than (-174)G allele carrier patients. However, we found this association to be present only in patients who carried the TNF-alpha (-308)A or IL-1beta (3954)T allele, i.e. in patients with high TNF-alpha and high IL-1beta producer genotypes. We suppose that in the case of high TNF-alpha and IL-1beta producer genotypes, elevated proinflammatory cytokine levels result in a higher production of IL-6 in (-174)G allele carrier patients. This elevated IL-6 level may have a protective effect against the development of T1DM and may delay the destruction of pancreatic beta-cells.

Survival and Proliferative Ability of Various Living Cell Types after Laser-Induced Forward Transfer

The survival, proliferation, and differentiation of freshly isolated and cultured cells were studied after absorbing film-assisted laser-induced forward transfer. Rat Schwann and astroglial cells and pig lens epithelial cells were used for transfer and the cells were cultured for 2 weeks after laser-pulsed transfer. All three cell types survived, proliferated, and differentiated under cell culture conditions and regained their original phenotype a few days after cell transfer. Time resolution studies have shown that the time required to accelerate the jets and droplets containing the cells was less than 1 micros and that the estimated minimum average acceleration of those ejected cells that reached a constant velocity was approximately 10(7) x g. This suggests that the majority of studied cells tolerated the extremely high acceleration at the beginning of the ejection and the deceleration during impact on the acceptor plate without significant damage to the original phenotype. These results suggest that the absorbing film-assisted laser-induced forward transfer technique appears to be suitable for several potential applications in tissue engineering and the biomedical tissue repair technologies.

Developmental dynamics of some blood biochemical parameters in the growing turkey (Meleagris gallopavo)

Blood serum clinical biochemical parameters of fasted BUT Big 8 male turkeys were determined at the ages of 3 days, 4, 8, 12, 16 and 20 weeks, for a follow-up of the developmental changes of some serum metabolites, enzymes and ions. The serum protein content (total protein, albumin, globulin) increased with age, indicating also the moulting-associated metabolic changes in the age interval from the 8th to the 12th weeks. Creatinine was shown to have a peak at 3 days of age (role of muscle activity in thermogenesis), while urate concentration sensitively reflected the dietary protein amount. Serum triglycerides peaked at the time of yolk catabolism, while cholesterol was shown to indicate the moulting, as was serum malondialdehyde. Serum sodium content increased throughout the study. Alanine aminotransferase and aspartate aminotransferase activities increased along the ontogeny, while alkaline phosphatase activity decreased in parallel with the growth. Serum creatine kinase activity showed an over one-magnitude increase. General metabolic and enzymatic alterations were characteristic and applicable for the description of the ontogenetic development of a precocial (post-hatch triglyceride peak), large bodied, meat-type (lactate dehydrogenase, continuously increasing creatine kinase) bird species.

Serum 25(OH)-vitamin D levels and bone metabolism in patients on maintenance hemodialysis

AIMS

An increasing amount of evidence suggests that 25-hydroxy vitamin D3 (25(OH)D3) may contribute to the bone health of patients with chronic kidney disease (CKD). The underlying vitamin D status of these patients, however, has often been neglected. In a cross-sectional study we assessed the association between vitamin D status and parathyroid function, bone turnover, bone mass and structure in patients on maintenance hemodialysis.

METHODS

69 patients on maintenance hemodialysis were assessed by bone densitometry (DEXA) and quantitative bone ultrasound (QUS). Serum 25-hydroxy vitamin D3 levels, serum markers of bone turnover and clinical data were tabulated.

RESULTS

A high prevalence of potentially significant vitamin D3 deficiency was found in this patient group: 59% of the patients had a 25(OH)D3 level below 20 nmol/l. There was a significant negative correlation between serum 25(OH)D3 levels and serum intact parathyroid hormone (iPTH) (r = -0.231, p < 0.05), and this association remained significant after controlling for potential covariables. Furthermore, we show here that serum 25(OH)D3 concentration is positively correlated with bone mineral density (BMD) measured at the radius (r = 0.424, p < 0.01). Finally, we show for the first time that 25(OH)D3 levels are significantly and independently correlated with broadband ultrasound attenuation (beta = 0.262, p < 0.05) measured with calcaneal quantitative bone ultrasound (QUS) in patients with chronic renal failure.

CONCLUSION

Vitamin D3 deficiency may contribute to the impaired bone health of patients on maintenance dialysis.

Photopigment coexpression in mammals: comparative and developmental aspects

In mammals, each cone had been thought to contain only one single type of photopigment. It was not until the early 1990s that photopigment coexpression was reported. In the house mouse, the distribution of color cones shows a characteristic division. Whereas in the upper retinal field the ratio of short wave to middle-to-long wave cones falls in the usual range (1:10), in the ventral retinal field M/L-pigment expression is completely missing. In the transitional zone, numerous dual cones are detectable (spatial coexpression). In other species without retinal division, dual cones appear during development, suggesting that M/L-cones develop from S-cones. Dual elements represent a transitory stage in M/L-cone differentiation that disappear with maturation (transitory coexpression). These two phenomena seem to be mutually exclusive in the species studied so far. In the comparative part of this report the retinal cone distribution of eight rodent species is reported. In two species dual cones appear in adult specimens without retinal division, and dual elements either occupy the dorsal peripheral retina, or make up the entire cone population. This is the first observation proving that all cones of a retina are of dual nature. These species are good models for the study of molecular control of opsin expression and renders them suitable sources of dual cones for investigations on the role and neural connections of this peculiar cone type. In the developmental part, the retinal maturation of other species is examined to test the hypothesis of transitory coexpression. In these species S-pigment expression precedes that of the M/L-pigment, but dual cones are either identified in a small number or they are completely missing from the developing retina. These results exclude a common mechanism for M/L-cone maturation: they either transdifferentiate from S-cones or develop independently.

Changes in the plasma concentration of soluble thrombomodulin in patients with severe carotid artery stenosis after eversion endarterectomy

OBJECTIVE AND DESIGN

The purpose of the study was to investigate the putative role of soluble thrombomodulin (sTM) in severe carotid artery stenosis.

MATERIALS AND METHODS

We prospectively studied 64 patients who were undergoing carotid endarterectomy (2001-2003). Plasma sTM concentration was determined in each patient before surgery and at 14 months postsurgery. -308 TNF-alpha promoter polymorphism was also determined.

RESULTS

Strong negative correlation was found between the preoperative duplex scan values and the plasma sTM concentrations (R = -0.418, p = 0.0006). Patients with 308 A TNF-alpha genotype had significantly lower (p = 0.0415) preoperative sTM values than their counterparts with no such polymorphism. Soluble TM concentrations measured in plasma samples taken at the end of the postsurgical follow-up period of 14 months duration were significantly higher compared to the preoperative values (p < 0.0001).

CONCLUSIONS

Our present findings indicate that sTM may be adsorbed to the atherosclerotic plaques or inflamed endothelium in carotid arteries. The pathological significance of this adsorption remains to be determined.

Measurement of belly composition variability in pigs by in vivo computed tomographic scanning

The belly region composition of a representative commercial pig sample of 130 castrates was examined by in vivo spiral computed tomographic (CT) scanning. The lean meat percentage, the muscle/fat tissue ratio within the total body and separately within the bacon part were estimated by image analysis. The lean meat content of the total body was determined by the EU reference method. A correlation of r = 0.97 was found between lean meat content of the total body determined by CT estimation and the slaughtering results. The pigs were divided into seven groups on the basis of their lean meat content. The muscle percentage of the bacon part was 26% and 67%, respectively, in the two groups representing the two extremes of lean meat percentage (36% and 67%, respectively). The total volume of the bacon part was relatively constant (8.6 +/- 1 dm3) in the groups representing different lean meat categories. At the same time, the fat tissue volume of the bacon part was considerably higher while its muscle tissue volume was markedly lower in the group of the lowest than in that of the highest lean meat content (6.6 vs. 2.5 dm3 and 2.4 vs. 5.5 dm3, respectively). To describe changes in the tissue composition of the bacon part during fattening, 10 castrates were scanned repeatedly at 70, 90 and 110 kg of liveweight. A linear regression model was developed to characterise the continuous decrease observed in the muscle/fat ratio within the bacon part due to increasing liveweight.

Differential utilization of hepatic and myocardial fatty acids during forced molt of laying hens

Feed was totally withdrawn from laying hens (n = 30, Hy-Line Brown, 608 d of age, 2.04 +/- 0.07 kg of mean BW) to induce molting. Ten birds were slaughtered on d 0 and 12, and the hepatic and myocardial triacylglycerol (TAG) and phospholipid (PL) fatty acid composition, as well as the tissue malondialdehyde (MDA) and reduced glutathione (GSH) concentrations were determined. The liver TAG and PL contents decreased by 24.3 and 16.1%, respectively, whereas the myocardial TAG content increased by 12%, and the PL decreased by 22%. Liver TAG fraction has been found to selectively retain arachidonic and docosahexanoic acids. Hepatic PL fatty acids were markedly affected by fasting; these changes reflected an altered PL metabolism, primarily degradation. Liver TAG compensated for the absence of dietary fatty acids, because we found practically no qualitative alteration in myocardial TAG. The lipid peroxide status, as measured with MDA content was, accordingly, increased in the liver tissue only. In the myocardial PL fatty acids, preferred conservation of arachidonic acid was shown, and it was hypothesized that energy deprivation of cardiomyocytes strongly improved PL degradation in fasting laying hens and influenced PL homeostasis. Generally the physiological recovery from forced molting associated with fasting is complete; however, the use of total feed withdrawal methods should be reevaluated.

Marked decrease in the levels of two inflammatory markers, hs-C-reactive protein and fibrinogen in patients with severe carotid atherosclerosis after eversion carotid endarterectomy

OBJECTIVE AND DESIGN

To study changes in the levels of two acute phase proteins, plasma fibrinogen and serum C-reactive protein (hs-CRP) in patients with severe carotid stenosis after eversion endarterectomy.

MATERIAL AND SUBJECTS

A total of 117 consecutive patients who underwent eversion endarterectomy were included in the study. Blood samples for acute phase protein measurement were taken before operation as well as 5.7 weeks and 13.8 months (median) post-surgery. Plasma fibrinogen and serum hs-CRP concentrations were promptly determined.

RESULTS

During the follow-up period sharp, highly significant (p < 0.0001) drop occurred in the serum concentrations of both acute phase proteins. The drop in the hs-CRP levels during the follow up period was mainly due to decrease in patients with highest baseline CRP levels.

CONCLUSIONS

Our present findings indicate that removal of atherosclerotic plaques from the carotid arteries markedly decreases the production of two acute phase proteins due to the decrease of the inflammatory burden or the removal of the advanced plaques able to produce these proteins.

The system of cerebrospinal fluid-contacting neurons. Its supposed role in the nonsynaptic signal transmission of the brain

Recent investigations confirm the importance of nonsynaptic signal transmission in several functions of the nervous tissue. Present in various periventricular brain regions of vertebrates, the system of cerebrospinal fluid (CSF)-contacting neurons seems to have a special role in taking up, transforming and emitting nonsynaptic signals mediated by the internal and external CSF and intercellular fluid of the brain. Most of the CSF-contacting nerve cells send dendritic processes into the internal CSF of the brain ventricles or central canal where they form terminals bearing stereocilia and a 9+0-, or 9+2-type cilium. Some of these neurons resemble known sensory cells of chemoreceptor-type, others may be sensitive to the pressure or flow of the CSF, or to the illumination of the brain tissue. The axons of the CSF-contacting neurons transmit information taken up by dendrites and perikarya to synaptic zones of various brain areas. By forming neurohormonal terminals, axons also contact the external CSF space and release various bioactive substances there. Some perikarya send their axons into the internal CSF, and form free endings there, or synapses on intraventricular dendrites, perikarya and/or on the ventricular surface of ependymal cells. Contacting the intercellular space, sensory-type cilia were also demonstrated on nerve cells situated in the brain tissue subependymally or farther away from the ventricles. Among neuronal elements entering the internal CSF-space, the hypothalamic CSF-contacting neurons are present in the magnocellular and parvicellular nuclei and in some circumventricular organs like the paraventricular organ and the vascular sac. The CSF-contacting dendrites of all these areas bear a solitary 9 x 2+0-type cilium and resemble chemoreceptors cytologically. In electrophysiological experiments, the neurons of the paraventricular organ are highly sensitive to the composition of the ventricular CSF. The axons of the CSF-contacting neurons terminate not only in the hypothalamic synaptic zones but also in tel-, mes- and rhombencephalic nuclei and reach the spinal cord as well. The supposed chemical information taken up by the CSF-contacting neurons from the ventricular CSF may influence the function of these areas of the central nervous system. Some nerve cells of the photoreceptor areas form sensory terminals similar to those of the hypothalamic CSF-contacting neurons. Special secondary neurons of the retina and pineal organ contact the retinal photoreceptor space and pineal recess respectively, both cavities being embryologically derived from the 3rd ventricle. The composition of these photoreceptor spaces is important in the photochemical transduction and may modify the activity of the secondary neurons. Septal and preoptic CSF-contacting neurons contain various opsins and other compounds of the phototransduction cascade and represent deep encephalic photoreceptors detecting the illumination of the brain tissue and play a role in the regulation of circadian and reproductive responses to light. The medullo-spinal CSF-contacting neurons present in the oblongate medulla, spinal cord and terminal filum, send their dendrites into the fourth ventricle and central canal. Resembling mechanoreceptors of the lateral line organ, the spinal CSF-contacting neurons may be sensitive to the pressure or flow of the CSF. The axons of these neurons terminate at the external CSF-space of the oblongate medulla and spinal cord and form neurohormonal nerve endings. Based on information taken up from the CSF, a regulatory effect on the production or composition of CSF was supposed for bioactive materials released by these terminals. Most of the axons of the medullospinal CSF-contacting neurons and the magno- and parvicellular neurosecretory nuclei running to neurohemal areas (neurohypophysis, median eminence, terminal lamina, vascular sac and urophysis) do not terminate directly on vessels, instead they form neurohormonal nerve terminals attached by half-desmosomes on the basal lamina of the external and vascular surface of the brain tissue. Therefore, the bioactive materials released from these terminals primarily enter the external CSF and secondarily, by diffusion into vessels and the composition of the external CSF, may have a modulatory effect on the bioactive substances released by the neurohormonal terminals. Contacting the intercellular space, sensory-type cilia were also demonstrated on nerve cells situated subependymally or farther away from the ventricles, among others in the neurosecretory nuclei. Since tight-junctions are lacking between ependymal cells of the ventricular wall, not only CSF-contacting but also subependymal ciliated neurons may be influenced by the actual composition of the CSF besides that of the intercellular fluid of the brain tissue. According to the comparative histological data summarised in this review, the ventricular CSF-contacting neurons represent the phylogenetically oldest component detecting the internal fluid milieu of the brain. The neurohormonal terminals on the external surface of the brain equally represent an ancient form of nonsynaptic signal transmission.

Noninvasive characterization of the turkey heart performance and its relationship to skeletal muscle volume

The cardiovascular capacity of turkeys is considerably affected by the selection procedure for meat production. To determine the body weight-related changes of some quantitative characteristics of the turkey heart function, serial measurements were carried out. BUT Big 6 turkeys (both sexes) were examined using whole-body magnetic resonance imaging (MRI) and spiral computer tomography (CT). Based on dynamic MRI examinations the following significant age- and sex-dependent quantitative differences were found. Means of the left ventricular stroke volumes were measured at the ages of 12 wk (males, 4.18 mL; females 2.89 mL), 16 wk (males, 6.56 mL; females, 4.14 mL), and 20 wk (males, 8.17 mL; females, 5.16 mL). Average cardiac output (CO) values were 0.76, 1.14, and 1.33 L/min for males and 0.58, 0.79,0.93 L/min for females. A statistically unproven age-dependent increasing tendency in the estimated relative CO value (skeletal muscle tissue volume measured by CT/CO unit) of male and female turkeys was found under sedentary conditions. These changes in the relative CO value and also the determined decrease of CO value related to body surface may, in theory, indicate a disadvantageous process that is more pronounced in males. The combined application of CT and MRI can be a powerful approach for studying the relationship between skeletal muscle development and heart capacity.

The inhibition of retinal inducible nitric oxide synthase overexpression and the attenuation of experimental uveitis by anti-inflammatory drugs in rats

OBJECTIVE AND DESIGN

The effect of a steroid and a non-steroid anti-inflammatory drug on the inducible nitric oxide synthase (NOS II) in rats suffering from lipopolysaccharide (LPS)-induced uveoretinitis was studied.

TREATMENTS

Rats were injected with LPS to induce uveitis and divided into three groups: treated with LPS only, LPS + dexamethasone and LPS + indomethacin, respectively.

METHODS

Retinal, peritoneal macrophages and white blood cells were isolated. The activity and the expression of NOS II were followed by citrulline formation and Western blotting, respectively. Phagocytosis of bacteria was also measured.

RESULTS

The best induction of NOS II was achieved by the intravitreal administration of LPS. Dexamethasone and indomethacin significantly decreased the activity and the expression of inducible nitric oxide synthase in retinal tissue, peritoneal macrophages and white blood cells. LPS treatment also increased phagocytosis and neither dexamethasone nor indomethacin reversed this effect.

CONCLUSIONS

The beneficial effects of these drugs in experimental uveitis are mediated, at least partly, by their inhibitory effect on NOS II induction.

Divergence of renal vascular endothelial growth factor mRNA expression and protein level in post-ischaemic rat kidneys

Vascular endothelial growth factor (VEGF) is a potent regulator of angiogenesis and vascular protection. Synthesis of VEGF is induced by hypoxia and different cytokines including interleukin-6 (IL-6) and interleukin-1beta (IL-1beta). However, post-ischaemic alterations of this growth factor in the kidney are incompletely known. To determine VEGF synthesis in renal ischaemia/reperfusion (I/R) injury unilateral warm ischaemia was induced by cross-clamping the left renal pedicle for 55 min followed by 2 and 24 h of reperfusion (T2 and T24 kidneys; n= 6 in each group). Sham-operated, non-clamped animals served as controls (n= 6). Renal VEGF, IL-6 and IL-1beta mRNA expression were determined by reverse transcription-polymerase chain reaction (RT-PCR). VEGF protein level and distribution were determined by Western blot and immunohistochemical analysis. Immunohistochemistry revealed prominent VEGF staining in the outer medulla of control, T2 and T24 kidneys. VEGF immunoreactivity accumulated at the basolateral area of tubular epithelial cells in T2 kidneys, while it was diffuse in control and T24 kidneys. VEGF protein levels were increased 2- to 3-fold in T2 and T24 kidneys (both P < 0.01 versus controls), while VEGF mRNA expression remained unchanged. IL-6 mRNA expression was increased (P < 0.01 versus controls) in T2 kidneys, while IL-1beta mRNA expression remained unchanged. Increased VEGF protein levels but not mRNA expression suggests that during renal I/R injury VEGF synthesis in kidneys--unlike in other organs--is primarily regulated at a post-transcriptional level. As IL-6 mRNA expression increased simultaneously with VEGF protein levels, the post-ischaemic regulation of IL-6 and VEGF synthesis might be interrelated in rat kidney.

Tracking of the hormonally induced maturation of female eels by computed tomography

Female European eels were kept in artificial seawater for a trial period of 14 weeks. Three fish were injected intra-abdominally with carp pituitary suspension (twice a week) and human chorionic gonadotropin (every 2nd week), with the aim to induce artificial maturation. Three further fish were not treated (control). Fish were not fed during the trial. The treated fish were scanned by computed tomography (CT) every second week (the controls only at the start and at the end of the trial) to follow changes in body composition. Notable decreases were shown in total body pixel number (body volume), total body fat content, total fillet volume and fillet fat content during the experiment. Changes were more pronounced in the treated group than in the control. The abdominal volume strongly increased in the responding fish throughout the trial. The ovary volume increased measurably, while its fat content increased only until the 8th week, after which a decrease was measured. Tissue volumetric estimations of the ovary were also supported by histological results. A so-called volumetric gonadosomatic index (gonad volume/total body volume x 100) was developed for the quantitative characterisation of eel maturation.