bluuebunny/crossref_metadata_2025 huggingface dataset:
Horizontal Basal Cells Are Multipotent Progenitors in Normal and Injured Adult Olfactory Epithelium
Authors: Iwai Naomi , Zhou Zhijian , Roop Dennis R. , Behringer Richard R.
Published: February 2008

The mammalian olfactory neuroepithelium provides a unique system for understanding the regulation of neurogenesis by adult neural stem cells. Recently, mouse horizontal basal cells (HBCs) were identified as stem cells that regenerate olfactory receptor neurons (ORNs) and non-neuronal cell types only after extensive injury of the olfactory epithelium (OE). Here we report a broader spectrum of action for these cells. We show that even during normal neuronal turnover, HBCs actively generate neuronal and non-neuronal cells throughout adulthood. This occurs in a temporally controlled manner: an initial wave of HBC-derived neurogenesis was observed soon after birth, and a second wave of neurogenesis was observed at 4 months of age. Moreover, upon selective depletion of mature ORNs by olfactory bulbectomy, HBCs give rise to more neurons. Our findings demonstrate a crucial role for HBCs as multipotent progenitors in the adult OE, acting during normal neuronal turnover as well as in acute regeneration upon injury.

Disclosure of potential conflicts of interest is found at the end of this article.
Mitogenic functions of endocrine gland-derived vascular endothelial growth factor and Bombina variegata 8 on steroidogenic adrenocortical cells
Authors: Keramidas Michelle , Faudot Caroline , Cibiel Agnès , Feige Jean-Jacques , Thomas Michaël
Published: February 2008

Endocrine gland-derived vascular endothelial growth factor (EG-VEGF) and its homolog Bombina variegata (Bv8), also termed prokineticin-1 and -2 (PK1 and PK2) respectively, are newly identified peptides with specific mitogenic activity on endocrine gland-derived endothelial cells. In the present study, we analyzed the sites of expression of EG-VEGF/PK1, Bv8/PK2, and their receptors (PKR1 and PKR2) in the adrenal cortex and checked for new biological functions of these factors on the endocrine cell compartment. RT-PCR and immunostaining analyses revealed that glomerulosa and fasciculata cells express both factors and both receptors. EG-VEGF/PK1 had no effect on the steroidogenic activity of both bovine glomerulosa and fasciculata cells but appeared to be mitogenic for both cell types. Binding of EG-VEGF/PK1 to fasciculata cells stimulated the phosphorylation of ERK1/2. Pretreatment with pertussis toxin suppressed this effect, indicating that it was Gi mediated. EG-VEGF/PK1 also increased the phosphorylation of Akt in endocrine cells of the adrenal cortex. EG-VEGF/PK1 and Bv8/PK2 thus represent new regulatory peptides acting as autocrine mitogens for endocrine cells.
Effects of estrogen on gene expression profiles in mouse hypothalamus and white adipose tissue: target genes include glutathione peroxidase 3 and cell death-inducing DNA fragmentation factor, α-subunit-like effector A
Authors: Lundholm Lovisa , Putnik Milica , Otsuki Michio , Andersson Sandra , Ohlsson Claes , Gustafsson Jan-Åke , Dahlman-Wright Karin
Published: February 2008

Obesity has become a major health problem in many parts of the world. Estrogens are known to reduce adipose tissue mass in both humans and animals but the molecular mechanisms are not well characterized. We used gene expression profiling to study long-term effects of estrogen on gene expression in mouse white adipose tissue and hypothalamus. Overall, the effects of estrogen on hypothalamic gene expression were much smaller than the corresponding effects on white adipose tissue gene expression. We characterize in detail estrogenic regulation of glutathione peroxidase 3 (GPX3). Our studies suggest that GPX3 is a direct estrogen receptor α target gene in white adipose tissue. Since obesity is correlated with oxidative stress, and GPX3 has been demonstrated to be lower in obesity and higher after weight loss, we hypothesize that GPX3 is one important mediator of effects of estrogen in relation to fat mass. Additional genes that were affected by estrogen in adipose tissue include cell death-inducing DNA fragmentation factor, α-subunit-like effector A (CIDEA), a gene shown to be related to body fat in mice. We conclude that estrogen has large effects on gene expression in white adipose tissue and hypothesize that GPX3 and CIDEA could be important mediators of the effects of estrogen on fat mass.
Misclassification Bias and the Estimated Effect of Parental Involvement Laws on Adolescents' Reproductive Outcomes
Authors: Colman Silvie , Joyce Ted , Kaestner Robert
Published: February 2008

Objectives. We evaluated the presence of misclassification bias in the estimated effect of parental involvement laws on minors’ reproductive outcomes when subjection to such laws was measured by age at the time of pregnancy resolution.

Methods. Using data from abortion and birth certificates, we evaluated the effect of Texas's parental notification law on the abortion, birth, and pregnancy rates of adolescents aged 17 years compared with those aged 18 years on the basis of age at the time of pregnancy resolution and age at conception.

Results. On the basis of age at the time of the abortion or birth, the law was associated with a fall of 26%, 7%, and 11% in the abortion, birth, and pregnancy rates, respectively, of 17- relative to 18-year-olds. Based on age at the time of conception, the abortion rate fell 15%, the birth rate rose 2%, and the pregnancy rate remained unchanged.

Conclusions. Previous studies of parental involvement laws should be interpreted with caution because their methodological limitations have resulted in an overestimation of the fall in abortions and underestimation of the rise in births, possibly leading to the erroneous conclusion that pregnancies decline in response to such laws.
Plasticizers and related toxic degradation products in wastewater sludges
Authors: Beauchesne I. , Barnabé S. , Cooper D. G. , Nicell J. A.
Published: February 2008

Plasticizers can persist during the treatment of wastewaters in sewage treatment plants (STPs) and can be discharged in effluents and/or accumulated in sewage sludges. For example, di-2-ethylhexyl phthalate (DEHP) is a common plasticizer that is now considered a priority pollutant and is known to accumulate in sludges. This may add constraints to the exploitation of the beneficial uses of sludges that contain significant quantities of plasticizers. Recently, it was demonstrated in studies with pure cultures that the biodegradation of plasticizers including DEHP and di-ethylhexyl adipate (DEHA) generates toxic metabolites including 2-ethylhexanoic acid, 2-ethylhexanol, and 2-ethylhexanal. However, the environmental impacts and fate of the degradation products arising from plasticizers are unknown. Therefore, this work investigated the concentrations of DEHP and DEHA and their metabolites in the sludges from several STPs in Quebec, Canada. DEHP and DEHA were found in concentrations ranging from 15 to 346 mg kg−1 and 4 to 743 mg kg−1, respectively, in primary, secondary, digested, dewatered or dried sludges. Metabolites were detected in almost all sludges, except those that had undergone a drying process at high temperature. It is concluded that sludges can represent significant sources of plasticizers and their toxic metabolites in the environment.
Long-term land application of biosolids–a case study
Authors: Surampalli R. Y. , Lai K. C. K. , Banerji S. K. , Smith J. , Tyagi R. D. , Lohani B. N.
Published: February 2008

Impact of long-term land application of biosolids on groundwater and soil quality of an application site, which had been operated for 8–15 years, was evaluated in this study. During and after the biosolids application, biosolids-amended soil, groundwater, and background soil samples were collected mainly for pathogen, nitrogen, phosphorus, and heavy metal analyses. Soil test data showed that there was no heavy metal accumulation in the biosolids-amended soil even after 10 years of biosolids application. Similar results were also observed from the groundwater samples in which the heavy metal concentrations in all groundwater samples were well below the maximum contamination levels of the drinking water standards. In addition, bacteriological levels of the soil and groundwater samples were close to the background level and below the permissible limits, respectively, thereby showing no pathogen contamination. However, nitrate-nitrogen contamination of the groundwater was occasionally observed probably due to an excess loading of the biosolids in the past. This problem can be alleviated by applying biosolids at agronomic rates so that no excess nitrogen is available for leaching down to the groundwater.
Development of a process for the recovery of phosphorus resource from digested sludge by crystallization technology
Authors: Shimamura K. , Ishikawa H. , Mizuoka A. , Hirasawa I.
Published: February 2008

Removal and recovery of phosphorus from sewage in form of MAP (magnesium ammonium phosphate) have attracted attention from the viewpoint of eutrophication prevention and phosphorus resource recovery as well as scaling prevention inside digestion tanks. In this work, phosphorus recovery demonstration tests were conducted in a 50 m3/d facility having a complete mixing type reactor and a liquid cyclone. Digested sludge, having 690 mg/L T-P and 268 mg/L PO4-P, was used as test material. The T-P and PO4-P of treated sludge were 464 mg/L and 20 mg/L achieving a T-P recovery efficiency of 33% and a PO4-P crystallization ratio of 93%. The reacted phosphorus did not become fine crystals and the recovered MAP particles were found to be valuable as a fertilizer. A case study in applying this phosphorus recovery process for treatment of sludge from an anaerobic-aerobic process of a 21,000 m3/d sewage system, showed that 30% of phosphorus concentration can be reduced in the final effluent, recovering 315 kg/d as MAP.
Anaerobic microbial LCFA degradation in bioreactors
Authors: Sousa D. Z. , Pereira M. A. , Alves J. I. , Smidt H. , Stams A. J. M , Alves M. M.
Published: February 2008

This paper reviews recent results obtained on long-chain fatty acids (LCFA) anaerobic degradation. Two LCFA were used as model substrates: oleate, a mono-unsaturated LCFA, and palmitate, a saturated LCFA, both abundant in LCFA-rich wastewaters. 16S rRNA gene analysis of sludge samples submitted to continuous oleate- and palmitate-feeding followed by batch degradation of the accumulated LCFA demonstrated that bacterial communities were dominated by members of the Clostridiaceae and Syntrophomonadaceae families. Archaeal populations were mainly comprised of hydrogen-consuming microorganisms belonging to the genus Methanobacterium, and acetate-utilizers from the genera Methanosaeta and Methanosarcina. Enrichment cultures growing on oleate and palmitate, in the absence or presence of sulfate, gave more insight into the major players involved in the degradation of unsaturated and saturated LCFA. Syntrophomonas-related species were identified as predominant microorganisms in all the enrichment cultures. Microorganisms clustering within the family Syntrophobacteraceae were identified in the methanogenic and sulfate-reducing enrichments growing on palmitate. Distinct bacterial consortia were developed in oleate and palmitate enrichments, and observed differences might be related to the different degrees of saturation of these two LCFA. A new obligately syntrophic bacterium, Syntrophomonas zehnderi, was isolated from an oleate-degrading culture and its presence in oleate-degrading sludges detected by 16S rRNA gene cloning and sequencing.
The Effect of Firms' Depreciation Method Choice on Managers' Capital Investment Decisions
Authors: Jackson Scott B.
Published: February 2008

This study examines whether straight-line depreciation, relative to accelerated depreciation, causes non-executive managers to make non-value-maximizing capital investment decisions. To do this, I conduct experiments in which managers must decide whether to continue using an existing asset or invest in a replacement asset. By design, replacing the existing asset yields higher cash flows and managers are aware of this fact. However, if the asset is replaced, then the greater remaining book value under straight-line depreciation relative to accelerated depreciation causes earnings to be lower. Lower earnings and psychological forces may push managers of firms that use straight-line depreciation away from making the economically efficient capital investment decision. The results suggest that managers of firms that use straight-line depreciation are less likely to invest in a replacement asset than are managers of firms that use accelerated depreciation. Further, the results suggest that managers perceive that an asset depreciated using straight-line depreciation has provided less retrospective utility than an asset depreciated using accelerated depreciation. In turn, I find that depreciation method-induced differences in managers' retrospective utility perceptions influence their prospective utility perceptions, which, in turn, influence managers' asset replacement decisions. By theoretically and empirically linking firms' depreciation method choice to managers' capital investment decisions, I provide evidence that a seemingly innocuous choice made for external financial reporting purposes can cause managers to make non-value-maximizing capital investment decisions.
Effects of the Solvent Evaporation Technique on the Degree of Conversion of One-Bottle Adhesive Systems
Authors: Giannini M. , Arrais C. A. G. , Vermelho P. M. , Reis R. S. , Santos L. P. S. , Leite E. R.
Published: February 2008

Clinical Relevance

Since methods of solvent evaporation can change the degree of conversion for some adhesives, practitioners should be aware of the type and composition of bonding agents used.
Shear Bond Strength of Self-etch Adhesives to Enamel with Additional Phosphoric Acid Etching
Authors: Lührs A-K. , Guhr S. , Schilke R. , Borchers L. , Geurtsen W. , Günay H.
Published: February 2008

Clinical Relevance

When using self-etch adhesives to bond composite materials to enamel, there is concern about the ability to achieve bond strengths comparable to approved etch-and-rinse systems. An additional phosphoric acid etching can improve the shear bond strength of self-etch adhesives to enamel.
Effect of Cyclic Loading on the Bond Strength of Class II Restorations with Different Composite Materials
Authors: Cavalcanti A. N. , Mitsui F. H. O. , Silva F. , Peris A. R. , Bedran-Russo A. , Marchi G. M.
Published: February 2008

Clinical Relevance

New resin composite technologies, such as nano-filled-based systems, have been developed. The assessment of such materials in a simulated laboratory chewing condition may assist with the selection of composites in a clinical situation.
Environmental Risk Assessment: Relation to Mutagenesis, Teratogenesis, and Reproductive Effects
Authors: Omenn Gilbert S.
Published: February 2008

Effective and efficient assessment of the potential health effects from environmental chemicals requires well-validated tests to identify the toxicity of the chemical and then extensive scientific and analytical work to characterize the potential risk for humans in light of the relative potency of the chemical in test systems, the nature and routes of exposures for humans, and the differences in susceptibility across species and among human population subgroups. Such risk assessment is being applied increasingly for potential carcinogens and is beginning to be applied to mutagenic and teratogenic chemicals. One of the fertile areas for research is the study of mechanisms that may permit us to predict carcinogenic, mutagenic, or teratogenic activity of compounds from tests of each of these classes of end-points.
A Comparative Study of Lead Nephrotoxicity and Tissue Deposition Between Rats, Mice, and Pigeons Exposed to Drinking Water Containing 2, 20, or 200 ppm Lead
Authors: Revis N. W. , Shaw Judith , Bull R.
Published: February 2008

White Carnaew pigeons were exposed to drinking water containing various concentrations of lead to study the relationship between exposure and tissue deposition and the relationship between the concentrations of lead in kidney and morphologic alterations. The concentration of lead in the blood was the only tissue which showed a linear increase with respect to the concentration of lead in the drinking water. The concentration of lead in the liver, kidney, brain, heart, aorta, and pancreas increased in response to lead in the drinking water; however, these increases were not linear with respect to lead exposure. Similar results were obtained for rats and mice exposed via the drinking water to 2, 20, or 200 ppm lead; however, the concentration of lead in tissues was substantially greater in pigeons. Kidneys from rats and mice appeared normal following the exposure of 200 ppm lead for 4 months, whereas, in kidneys from pigeons exposed to 200 ppm for a similar period of time there was tubular degeneration, fibrosis, and acid fast intranuclear inclusion bodies. These pathoanatomic alterations may be related to the concentration lead found in the kidney in pigeons. The concentration of lead in the kidney was 3,930 μg gram dry weight for pigeons but only 40 and 6 μg for mice and rats respectively. These studies suggest that the pigeon is more responsive to ingested lead than the rat or mouse. The renal lesions induced by chronic lead exposure are similar in pigeons and man suggesting that the pigeon may be useful animal model to study the yet unanswered questions related to chronic nephritis following lead poisoning.
Seminal Cytology and Reproductive Toxicology of N-Chloropiperidine
Authors: Bempong Maxwell A. , Scully Frank E.
Published: February 2008

Induction of sperm abnormality in mice and hamster and reproductive toxicity in mice was examined following chronic exposures (ad libitum) to N-chloropiperidine (NCP). The results showed that significant levels of abnormal sperm in the NCP treated group were observed after five weeks of exposure. The time of the appearance of NCP-induced anomalous sperm suggested that the compound did not affect late spermatocytes and spermiogenesis. Reproductive toxicological analysis based on moles, implantations, and offspring per pregnancy revealed that while the toxic effect of ethylmethane sulfonate was evident within the first week of treatment, NCP-induced toxicity was observed only after five weeks of treatment. The data further showed that in matings where both parents were exposed to NCP, the frequencies of moles, implantations, and offspring per pregnancy were fewer than those observed in single parent exposure.
Serum and Lung Clearance of Exogenous Horseradish Peroxidase: Influence of Low Levels of Nitrogen Dioxide
Authors: Sherwin Russell P. , Okimoto Dave T. , Mundy Dorothy , Richters Valda
Published: February 2008

Serum and tissue homogenates of lung and kidney from 264 mice, half of which had been exposed to continuous or intermittent nitrogen dioxide (NO3 at levels of 0.5 ppm, 0.6 ppm, and 0.8 ppm in three independent experiments, were assayed for intravenously introduced horseradish peroxidase (HRP), a molecular probe for protein leakage. Disc gel elec-trophoresis and enzyme kinetic assays were used independently to quantitate HRP content after 3 and 6 weeks of NO2 exposure, and at 5.5 hr after HRP injection. Of 6 test periods, 5 showed a greater lung HRP content for the NO2, exposed animals by gel scan analysis, and 3 of the 5 increases were statistically significant (p >.05, p >.025, and p >.0025). Similar trends were noted with the HRP kinetic assay. Serum and kidney comparisons showed no consistent differences; 1 of 6 test periods for each was statistically significant. The findings implicate an NO2, induced overload of the bidirectional protein transport system of the lung.
Could late rebleeding overturn the superiority of cranial aneurysm coil embolization over clip ligation seen in the International Subarachnoid Aneurysm Trial?
Authors: Mitchell Patrick , Kerr Richard , Mendelow A. David , Molyneux Andy
Published: February 2008

Object

The present purpose is to define the sensitivity of the superiority of coil embolization observed in the International Subarachnoid Aneurysm Trial (ISAT) according to the rate of late rebleeding over a reasonable range, and to find the range of rebleeding rates for which it may be overturned. In the ISAT, coil embolization appears to be safer than clip ligation at 1 year, and clip occlusion has better long-term efficacy at preventing rebleeding. This leaves open the question of which is better in the longer term.

Methods

The authors calculate the life expectancy of patients following a subarachnoid hemorrhage (SAH) and compare the life expectancy of those who underwent coil embolization with those who underwent clip ligation in the ISAT cohort.

Results

The 1-year poor outcome rate following treatment climbs rapidly with advancing age. A consequence is that the absolute difference between the poor outcome rates after coil embolization and clip occlusion is lower in those < 50 years of age (3.3%) than it is for those > 50 years of age (10.1%). This difference may be enough to give clip application the advantage in the < 40-year-old group despite the small size of the difference in 1-year rebleeding rates thus far observed (0.152%).

Conclusions

When treating ruptured cerebral aneurysms, the advantage of coil embolization over clip ligation cannot be assumed for patients < 40 years old. In this age range the difference in the safety of the 2 procedures is small, and the better long-term protection from SAH afforded by clip placement may give this treatment an advantage in life expectancy for patients < 40 years of age.
Intracranial aneurysms treated with Guglielmi detachable coils: long-term imaging follow-up with contrast-enhanced magnetic resonance angiography
Authors: Gauvrit Jean-Yves , Caron Sabine , Taschner Christian A. , Lejeune Jean-Paul , Pruvo Jean-Pierre , Leclerc Xavier
Published: February 2008

Object

The aim of this study was to assess the long-term results of intracranial aneurysms treated with Guglielmi detachable coils (GDCs) with the aid of contrast-enhanced magnetic resonance (MR) angiography.

Methods

Between January 1998 and August 2001, 92 patients with 92 aneurysms treated by endovascular coiling with GDCs underwent contrast-enhanced MR angiography. These patients underwent long-term follow-up (range 32–78 months, mean 42.1 ± 11.9 months [standard deviation]) after endovascular treatment. All images were compared with digital subtraction angiograms and contrast-enhanced MR angiograms that had been obtained during the short-term follow-up (range 5–25 months, mean 13 ± 5.1 months after treatment). The MR angiograms were analyzed independently by 2 senior radiologists. Findings were assigned to 1 of 3 categories: complete obliteration (Class 1), residual neck (Class 2), or residual aneurysm (Class 3).

Results

Of 92 contrast-enhanced MR angiograms obtained at the long-term follow-up, complete obliteration of the aneurysm was noted in 57 patients (Class 1), a residual neck was seen in 22 (Class 2), and a residual aneurysm was observed in 13 (Class 3). One patient experienced aneurysm rehemorrhaging during the follow-up period. The comparison of short- and long-term follow-up angiograms demonstrated a change in aneurysm classification in 7 patients (7.6%), including 4 that progressed from Class 1 to Class 2 and 3 from Class 2 to Class 3. However, 4 (14.2%) of the 28 long-term recurrences were not detected on the short-term control images.

Conclusions

Long-term follow-up with contrast-enhanced MR angiography after selective embolization of intracranial aneurysms can identify late aneurysm recanalization that is undetected at short-term follow-up.
High-dose intraarterial verapamil in the treatment of cerebral vasospasm after aneurysmal subarachnoid hemorrhage
Authors: Keuskamp Janine , Murali Raj , Chao Kuo H.
Published: February 2008

Object

Because oral calcium channel blockers appear to reduce the severity of cerebral vasospasm after aneurysmal subarachnoid hemorrhage (SAH), interest in their application intraarterially has emerged for cases in which noninvasive means of alleviating vasospasm are unsuccessful. Studies to date have been limited to the administration of low intraarterial doses because of concerns about hemodynamic stability and changes in intracranial pressure. These doses, although effective in cases of milder vasospasm, were inadequate in severe cases. The authors present a series of 10 patients with cerebral vasospasm who underwent 12 procedures in which they received ≥ 20 mg of intraarterial verapamil per procedure.

Methods

A retrospective review was undertaken of all patients who underwent endovascular treatment for cerebral vasospasm due to aneurysmal SAH by the senior author between February 2005 and October 2006. Ten patients were identified who had undergone a total of 12 procedures during which ≥20 mg of intraarterial verapamil had been administered. From angiography reports, anesthesia records, and nursing records, we obtained pre- and postverapamil mean arterial blood pressures (MABPs), heart rates, intracranial pressures (ICPs) (when available), and visible changes in the degree of vasospasm.

Results

No statistically significant changes in MABP, heart rate, or ICP were observed after administration of ≥ 20 mg of intraarterial verapamil, and the degree of improvement in vasospasm was statistically significant based on our grading system. No correlation was found between the change in hemodynamic parameters and the total dose of verapamil.

Conclusions

This study indicates that high-dose intraarterial verapamil may be used to treat cerebral vasospasm without compromising hemodynamic stability or increasing ICP.
Functional assessment of C-5 ventral rootlets by intraoperative electrical stimulation of the supraclavicular segment of the long thoracic nerve during brachial plexus surgery
Authors: Flores Leandro Pretto
Published: February 2008

Object

Anatomical and functional assessment of the intradural segment of the spinal nerves is imperative in brachial plexus surgery, as the repair of postganglionic elements in the setting of a confirmed nerve root avulsion is of no benefit. None of the current techniques to detect these avulsions can provide full information that ensures the functional status of the preganglionic segment of the roots. The objective of this study was to evaluate intraoperative electrical stimulation of the supraclavicular segment of the long thoracic nerve (LTN) as a method to differentiate C-5 nerve root extraforaminal rupture from its intradural avulsion.

Methods

The author performed a prospective analysis of data obtained in 14 patients presenting with the loss of C-5 nerve root function secondary to traumatic brachial plexus injury. The patients were divided into 2 groups: 8 patients in whom the intradural segment of C-5 nerve root was preserved (5 cases of closed traction injuries in whom the computed tomography [CT] myelograms confirmed the integrity of C-5 root and 3 cases of open sharp injuries) and a control group of 6 patients in whom CT myelography demonstrated avulsion of the root.

Results

The results of the intraoperative electrical stimulation of the LTN and the surgical outcome of each patient were recorded. The LTN electrical stimulation elicited serratus anterior muscle contraction in cases in which C-5 root was not avulsed, and there were no responses in patients whose radiological evaluation had demonstrated nerve root avulsion. In those patients in whom LTN stimulation proved to be positive, the C-5 root was used as a graftable stump to the suprascapular nerve and/or to the posterior division of the superior trunk. In these cases, favorable results were observed regarding arm abduction in all cases—Medical Research Council Grades M3 (37%) and M4 (62%). In the control group, the C-5 root was not used as a donor stump and a multiple nerve transfer technique was adopted as the preferred surgical option.

Conclusions

Intraoperative electrical stimulation of the supraclavicular segment of the LTN is a useful complementary method to test the functional status of the C-5 ventral rootlets. If the test is positive (that is, a response is present) it is indicative of extraforaminal rupture of the root, and if negative, it is suggestive of its avulsion.
Use of hemoglobin-based oxygen-carrying solution–201 to improve resuscitation parameters and prevent secondary brain injury in a swine model of traumatic brain injury and hemorrhage
Authors: Rosenthal Guy , Morabito Diane , Cohen Mitchell , Roeytenberg Annina , Derugin Nikita , Panter S. Scott , Knudson M. Margaret , Manley Geoffrey
Published: February 2008

Object

Traumatic brain injury (TBI) often occurs as part of a multisystem trauma that may lead to hemorrhagic shock. Effective resuscitation and restoration of oxygen delivery to the brain is important in patients with TBI because hypotension and hypoxia are associated with poor outcome in head injury. We studied the effects of hemoglobin-based oxygen-carrying (HBOC)–201 solution compared with lactated Ringer (LR) solution in a large animal model of brain injury and hemorrhage, in a blinded prospective randomized study.

Methods

Swine underwent brain impact injury and hemorrhage to a mean arterial pressure (MAP) of 40 mm Hg. Twenty swine were randomized to undergo resuscitation with HBOC-201 (6 ml/kg) or LR solution (12 ml/kg) and were observed for an average of 6.5 ± 0.5 hours following resuscitation. At the end of the observation period, magnetic resonance (MR) imaging was performed. Histological studies of swine brains were performed using Fluoro-Jade B, a marker of early neuronal degeneration.

Results

Swine resuscitated with HBOC-201 had higher MAP, higher cerebral perfusion pressure (CPP), improved base deficit, and higher brain tissue oxygen tension (PbtO2) than animals resuscitated with LR solution. No significant difference in total injury volume on T2-weighted MR imaging was observed between animals resuscitated with HBOC-201 solution (1155 ± 374 mm3) or LR solution (1246 ± 279 mm3; p = 0.55). On the side of impact injury, no significant difference in the mean number of Fluoro-Jade B–positive cells/hpf was seen between HBOC-201 solution (61.5 ± 14.7) and LR solution (48.9 ± 17.7; p = 0.13). Surprisingly, on the side opposite impact injury, a significant increase in Fluoro-Jade B–positive cells/hpf was seen in animals resuscitated with LR solution (42.8 ± 28.3) compared with those resuscitated with HBOC-201 solution (5.6 ± 8.1; p < 0.05), implying greater neuronal injury in LR-treated swine.

Conclusions

The improved MAP, CPP, and PbtO2 observed with HBOC-201 solution in comparison with LR solution indicates that HBOC-201 solution may be a preferable agent for small-volume resuscitation in brain-injured patients with hemorrhage. The use of HBOC-201 solution appears to decrease cellular degeneration in the brain area not directly impacted by the primary injury. Hemoglobin-based oxygen-carrying–201 solution may act by improving cerebral blood flow or increasing the oxygen-carrying capacity of blood, mitigating a second insult to the injured brain.
A complex cavernous sinus dural arteriovenous fistula secondary to covered stent placement for a traumatic carotid artery–cavernous sinus fistula
Authors: Lv Xian-Li , Li You-Xiang , Liu Ai-Hua , Lv Ming , Jiang Peng , Zhang Jing-Bo , Wu Zhong-Xue
Published: February 2008

✓The authors present the case of a patient with a direct carotid artery–cavernous sinus fistula caused by head trauma in whom a self-expanding covered stent was successfully used to obliterate the fistula. However, at the 9-month follow-up an angiogram revealed a complex caroticocavernous fistula that was completely obliterated with Onyx 18 transarterially.
Treatment of recurrent ventriculoperitoneal shunt failure associated with persistent cerebrospinal fluid eosinophilia and latex allergy by use of an “extracted” shunt
Authors: Ellis Michael J. , Kazina Colin J. , Del Bigio Marc R. , McDonald Patrick J.
Published: February 2008

✓Shunt failure is commonly associated with infection or mechanical obstruction of the shunt system. The presence of eosinophilia in the cerebrospinal fluid (CSF) has been associated with CSF shunt failure and may be related to both latex and shunt allergies. The authors describe the case of a child with a latex allergy who presented with 10 episodes of shunt failure over a period of 93 months. Cerebrospinal fluid sampling demonstrated persistent eosinophilia (3–36%) and negative cultures. Pathological examination of the ventricular catheter on 3 occasions demonstrated mechanical obstruction by inflammatory debris consisting largely of eosinophils and multinucleated giant cells. On the suspicion that the child might have some uncharacterized allergy to the shunt hardware, shunt replacement was performed using an “extracted” shunt system. The child has remained free of shunt malfunction for > 2 years since the last surgery. Immune responses to unpolymerized silicone are discussed.
Extracranial carotid artery pseudoaneurysm presenting with embolic stroke in a pediatric patient
Authors: Wolfe Stacey Quintero , Mueller-Kronast Nils , Aziz-Sultan Mohammad Ali , Zauner Alois , Bhatia Sanjiv
Published: February 2008

✓Extracranial carotid artery (CA) aneurysms are rare in the pediatric population and are usually the result of connective tissue disorders, traumatic dissection, or infection. The authors present the case of a large calcified internal carotid artery pseudoaneurysm of obscure origins presenting with embolic stroke in a child. Aneurysm excision and CA reconstruction would have been extremely difficult due to the distal location of the lesion, and CA ligation was contraindicated due to a failed balloon test occlusion. Therefore, after anticoagulation therapy, the patient was treated endovascularly with a covered stent and complete exclusion of the aneurysm from the circulation. The patient recovered all neurological function and has remained in excellent condition. A follow-up angiogram performed at 6 months showed no recurrence or stenosis.
Oscillation frequencies of tapered plant stems
Authors: Spatz Hanns‐Christof , Speck Olga
Published: February 2008

Free oscillations of upright plant stems, or in technical terms, slender tapered rods with one end free, can be described by considering the equilibrium between bending moments in the form of a differential equation with appropriate boundary conditions. For stems with apical loads, where the mass of the stem is negligible, Mathematica 4.0 returns solutions for tapering modes α = 0, 0.5, and 1. For other values of α, including cases where the modulus of elasticity varies over the length of the stem, approximations leading to an upper and a lower estimate of the frequency of oscillation can be derived. For the limiting case of ω = 0, the differential equation is identical with Greenhill's equation for the stability against Euler buckling of a top‐loaded slender pole. For stems without top loads, Mathematica 4.0 returns solutions only for two limiting cases, zero gravity (realized approximately for oscillations in a horizontal orientation of the stem) and for ω = 0 (Greenhill's equation). Approximations can be derived for all other cases. As an example, the oscillation of an Arundo donax plant stem is described.
The biomechanics of Pachycereus pringlei root systems
Authors: Niklas Karl J. , Molina‐Freaner Francisco , Tinoco‐Ojanguren Clara , Paolillo Dominick J.
Published: February 2008

We report on the root system of the large columnar cactus species Pachycereus pringlei to explore the hypothesis that increasing plant size decreases the ability to resist wind‐throw but increases the capacity to absorb and store nutrients in roots (i.e., plant size limits the performance of these functions and may shift the performance of one function in favor of another as size increases). Based on 18 plants differing in size, the root system is characterized by a broad and deep bayonet‐like root central to a shallow and extensive lateral system of root elements bearing sinker roots near the stem base. All root types have a living secondary cortex and contain wood with a large volume fraction of ray tissues that increases toward the stem base. Wood stiffness and tensile strength are correlated negatively with the ray tissue volume fraction and thus decrease toward the stem base in lateral and bayonet roots. Calculations show that the ability of the bayonet and proximal lateral root elements to resist wind‐throw decreases with increasing plant size, whereas the nutrient absorption/storage capacity of the total root system increases with plant size (i.e., a size‐dependent shift between these two root functions occurs).
The application of SSRs characterized for grape (Vitis vinifera) to conservation studies in Vitaceae
Authors: Arnold Claire , Rossetto Maurizio , McNally Jody , Henry Robert J.
Published: February 2008

The use of microsatellite loci developed from a single plant species across a number of related taxa is becoming increasingly widespread. This approach can provide highly informative markers even for species for which microsatellites have not been characterized. As a number of expressed sequence tag (EST)‐derived and enrichment‐derived microsatellites are available for grape (Vitis vinifera), this study set out to assess transferability of nine such loci across 25 species from five different Vitaceae genera. Intergeneric transfer success in Vitaceae was high (51.1%) and EST‐derived loci performed better than enrichment‐derived loci. Six loci were further tested across two Australian native species, Cissus hypoglauca and C. sterculiifolia, in order to assess the conservation of microsatellite repeats and their flanking sequences. Polymorphism of these selected loci was successfully tested for each species across a small, isolated rain forest population from northern New South Wales (Australia). Results from this preliminary investigation suggest that it is possible to use grape‐derived simple sequence repeats (SSR) loci for population studies on Vitaceae. As Vitaceae are an important component of rain forest flora, the availability of such highly informative loci will be beneficial to future studies aimed at determining the genetic consequences of rain forest fragmentation.
Novel morphology inEnteromorpha(Ulvophyceae) forming green tides
Authors: Blomster Jaanika , Bäck Saara , Fewer David P. , Kiirikki Mikko , Lehvo Annamaija , Maggs Christine A. , Stanhope Michael J.
Published: February 2008

“Green tides” are vast accumulations of unattached green macroalgae associated with eutrophicated marine environments. They have major ecological and economic impacts globally, so an understanding of their origin and persistence is required in order to make management decisions. Blooms predominantly consist of two common fouling genera of the Ulvales,Ulva(distromatic sheets) andEnteromorpha(monostromatic tubes). In the Baltic Sea and elsewhere green tides have increased over the last few decades. On the west coast of Finland, summer blooms consist of monostromatic sheets resemblingMonostroma(Codiolales). We identified these asEnteromorpha intestinalisby comparative analyses of rDNA internal transcribed spacer 1 (ITS1), 5.8S, and ITS2 sequences, the first time monostromatic sheets have been found in the genusEnteromorpha. Ordinary attachedE. intestinalissporulated freely in culture, but the sheets reproduced only by cell regeneration into typical tubular thalli. The ITS sequences were identical to those of attachedE. intestinalispopulations in southwestern Finland, but differed by two substitutions from other Baltic sequences. We infer that this bloom originated from local attached populations and now reproduces clonally by fragmentation. This study provides further evidence of radical changes in gross morphology of green algae under eutrophicated conditions and the need for molecular identification.
Floral anatomy and systematics of Alliaceae with particular reference to Gilliesia, a presumed insect mimic with strongly zygomorphic flowers
Authors: Rudall Paula J. , Bateman Richard M. , Fay Michael F. , Eastman Alison
Published: February 2008

The floral structure of Alliaceae is assessed in relation to the systematics of the family, especially the nature of the component parts of the remarkably insect‐like flower of Gilliesia graminea. Both presence of solid styles and possession of tenuinucellate ovules represent consistent synapomorphies for Alliaceae and support the separation of Agapanthus and Themidaceae from Alliaceae. Within Alliaceae, absence of septal nectaries (i.e., complete fusion of carpel margins) is a synapomorphy for the sister genera Gilliesia and Gethyum; septal nectaries are present in all other Alliaceae. A gynobasic style and reduced ovule number are probable synapomorphies for the genus Allium. In contrast to most other Alliaceae, in Gethyum and Gilliesia only three (abaxial) stamens (A1, a1, a2) are expressed, as in the apostasioid orchid Neuwiedia, but the perianth of Gethyum is only slightly bilaterally symmetric (zygomorphic), whereas Gilliesia graminea shows bilateral symmetry in all three floral whorls: perianth (suppression of the inner adaxial tepal in most flowers), androecium (suppression of three adaxial stamens), and gynoecium (slight bilateral symmetry, evident in transverse section). The precise relationships of Miersia and Solaria, the other two genera of Alliaceae with bilaterally symmetric flowers, are unknown, but their morphology indicates a close relationship with Gilliesia and Gethyum. Appendages of tepaline origin occur in Gethyum, Gilliesia, and Miersia; their papillate epidermis suggests that they function as osmophores. Their presence in Miersia, which has six stamens, indicates that these novel structures, which develop late in floral ontogeny, evolved independently from stamen suppression in this group. Within Gilliesia graminea, the genetic mechanisms controlling tepal number and shape are apparently unstable, resulting in fluctuating asymmetry. In G. graminea the possession of insect mimicry, presence of osmophores and absence of nectar together indicate a deceitful pollination mechanism similar to that of some Orchidaceae; this would make Gilliesia highly unusual among non‐orchid monocots, given that pollination by sexual deceit is normally regarded as exclusive to orchids.
Root deployment and shoot growth for two desert species in response to soil rockiness
Authors: Martre Pierre , North Gretchen B. , Bobich Edward G. , Nobel Park S.
Published: February 2008

Soil texture, as well as the presence of rocks, can determine the water status, growth, and distribution of plants in arid environments. The effects of soil rockiness and soil particle size distribution on shoot and root growth, root system size, rooting depth, and water relations were therefore investigated for the Crassulacean acid metabolism leaf succulent Agave deserti and the C4 bunchgrass Pleuraphis rigida after precipitation events during the summer and winter/spring rainfall periods in the northwestern Sonoran Desert. The soils at the field site varied from sandy (<3% rocks by volume) to rocky (up to 35% rocks), with greater water availability at higher water potentials for sandy than for rocky soils. Although A. deserti was absent from the sandiest sites, its shoot and root growth during both rainfall periods were greatest in comparatively sandier sites and decreased as the soil rock content increased. Furthermore, A. deserti had twofold greater root surface area, root : leaf area ratio, and mean rooting depth at sandier than at rocky sites. As for A. deserti, shoot growth was greater for P. rigida at the sandier sites than at the rockier sites, even though its root surface area and mean rooting depth did not vary significantly. After early spring rainfall events, the leaf water potential for A. deserti did not differ between rocky and sandy sites, but transpiration rates were almost twofold greater at rocky than at sandy sites. During the same period, P. rigida had lower leaf water potentials and 25% lower transpiration rates at rocky than at sandy sites. The greater variability in the deployment of the root systems of A. deserti in response to soil rockiness may reflect its evergreen habit and slower growth, which allow it to endure periods of lower water availability than does P. rigida, whose leaves die during drought.
A phylogeny of the rice tribe Oryzeae (Poaceae) based on matK sequence data
Authors: Ge Song , Li Ang , Lu Bao‐Rong , Zhang Shou‐Zhou , Hong De‐Yuan
Published: February 2008

Phylogenetic relationships were inferred using nucleotide sequences of the chloroplast gene matK for 26 species representing 11 genera of the tribe Oryzeae and three outgroup species. The sequenced fragments varied from 1522 base pairs (bp) to 1534 bp in length with 15.4% variable and 7.9% phylogenetically informative sites when the outgroups were excluded. The aligned sequences were analyzed by maximum parsimony and neighbor‐joining methods. Analyses of the sequence data indicated that species of Oryzeae form a strongly supported monophyletic group, concordant with previous morphological and anatomical evidence. The tribe Oryzeae can be divided into two monophyletic lineages, corresponding to the traditionally recognized subtribes Oryzinae and Zizaniinae. The first subtribe consists of Oryza and Leersia, while the subtribe Zizaniinae includes the remaining genera. The matK sequence data did not support the close affinities of the monoecious genera in Oryzeae, implying the possibility of multiple origins of the floral structures in the tribe. It is noteworthy that Porteresia coarctata is closely related to Oryza species, suggesting that it should be treated as a member in the genus Oryza rather than a separate monotypic genus.
Glacial history of the alpine herb Rumex Nivalis (Polygonaceae): a comparison of common phylogeographic methods with nested clade analysis
Authors: Stehlik Ivana
Published: February 2008

The glacial history of the alpine herb Rumex nivalis was investigated using amplified fragment length polymorphisms (AFLPs) and restriction fragment length polymorphisms with polymerase chain reaction (PCR‐RFLPs) of cpDNA. Both traditional statistical methods widely applied in phylogeographic research and nested clade analysis were used. The AFLPs indicated little geographic structure probably due to the wind‐pollinated reproductive system of the dioecious R. nivalis. Because cpDNA haplotypes exhibited distinct distributional patterns, correlation between AFLPs and PCR‐RFLPs was low. The results of common statistical methods and of nested clade analysis were largely congruent. Both supported in situ survival of one group of common haplotypes in the Central Alps. For another group of common haplotypes, classical phylogeographic analyses gave strong evidence for survival in peripheral refugia at the northern alpine border, whereas this conclusion was not as clearly supported in the nested clade analysis. Nested clade analysis provided several detailed insights on past and ongoing populational demographic processes. Thus, it is a valuable tool in the phylogeographical analysis of haplotype data, but it should preferably be combined with other statistical analyses. In situations with low genetic variation in cpDNA, classical phylogeographic analytical tools on nuclear DNA will still be the methods of choice.