Comparison of mandibular motion in horses chewing hay and pellets

REASONS FOR PERFORMING STUDY

Previous studies have suggested that temporomandibular joint (TMJ) kinematics depend on the type of food being masticated, but accurate measurements of TMJ motion in horses chewing different feeds have not been published.

HYPOTHESIS

The temporomandibular joint has a larger range of motion when horses chew hay compared to pellets.

METHODS

An optical motion capture system was used to track skin markers on the skull and mandible of 7 horses as they chewed hay and pellets. A virtual marker was created on the midline between the mandibles at the level of the 4th premolar teeth to represent the overall motion of the mandible relative to the skull during the chewing cycle.

RESULTS

Frequency of the chewing cycles was lower for hay than for pellets. Excursions of the virtual mandibular marker were significantly larger in all 3 directions when chewing hay compared to pellets. The mean velocity of the virtual mandibular marker during the chewing cycle was the same when chewing the 2 feeds.

CONCLUSIONS

The range of mediolateral displacement of the mandible was sufficient to give full occlusal contact of the upper and lower dental arcades when chewing hay but not when chewing pellets.

POTENTIAL RELEVANCE

These findings support the suggestion that horses receiving a diet high in concentrate feeds may require more frequent dental prophylactic examinations and treatments to avoid the development of dental irregularities associated with smaller mandibular excursions during chewing.

A phase I study of imatinib mesylate and paclitaxel in patients with advanced (stage IIIC/IV) or recurrent uterine papillary serous carcinoma (UPSC)

16025

Background: Uterine serous carcinoma (USC) is a rare, aggressive uterine tumor biologically distinct from typical endometrial cancers. Imatinib mesylate (IM)-associated kinases (kit, abl, PDGFR-B) are overexpressed and activated in most tumors from patients (pts) with USC. Single agent paclitaxel (TAX) has a good response rate but short duration of response in pts with USC. The purpose of this study was to determine the maximum tolerated dose (MTD) and dose limiting toxicity (DLT) of escalated doses of IM with a fixed dose of TAX. Methods: Pts with newly diagnosed (stage IIIC/IV) or recurrent USC were eligible (pts were required to have tumors that expressed at least one of the IM-targeted kinases by immunohistochemistry). Measurable disease was not required. TAX was administered at 175 mg/m2 every three weeks. One dose reduction to 135 mg/m2 was allowed. IM was given daily (400 mg, 500 mg or 600 mg). A 3+3 design was implemented. Pts with measurable disease were treated until progression or treatment associated toxicity. Pts with no measurable disease were treated for six cycles. Results: 11 pts were enrolled. The median age was 62 years (47–79). A total of 50 cycles were administered. Three pts were treated at the first dose level (400 mg), 6 pts treated at the second dose level (500 mg), and 2 pts were treated at the highest dose level (600 mg). Three DLTs were observed (1 at 500 mg level and 2 at 600 mg level) including: rash, neutropenia, and fatigue. IM 500 mg daily and TAX 175 mg/m2 every three weeks was the MTD. There were 3 serious adverse events not related to treatment (infection, dyspnea, pain). Neutropenia was the most common grade 3 or 4 toxicity but only one patient required TAX dose reduction. 8 pts were evaluated for efficacy (2 with measurable disease, 6 with no measurable disease). 1 (of 2) pts with measurable disease had a partial response and was treated for 13 cycles. Of the 6 pts with no measurable disease, 2 recurred (5 and 10 months). The median disease free interval for the pts without recurrent disease was 22 months (6–30). Conclusion: Combination therapy of IM and TAX is well tolerated with minimal side effects in pts with advanced or recurrent USC. Initiation of the phase II component of this study is warranted to better evaluate efficacy.

No significant financial relationships to disclose.

A phase I trial of the proteosome inhibitor PS-341 in combination with carboplatin in platinum and taxane resistant ovarian cancer patinets

5558

Background. PS-341 (Millenium Pharmaceuticals, Inc.), a proteosome inhibitor, affects p53, NFκB, cell adhesion molecules, and sensitivity to cytotoxic agents to promote apoptosis and inhibit metastasis in cancer cells. PS-341 alone rarely causes myelosupression or renal toxicity, and therefore is an attractive agent to use in combination with cytotoxic chemotherapy. This phase I study evaluates the safety, dose-limiting toxicities (DLTs), and optimal dose of PS-341 when combined with carboplatin in ovarian cancer patients with recurrent, platinum- and taxane-resistant disease. Methods: After IRB approval, patients with recurrent ovarian cancer, platinum and taxane resistant (progression on platinum and/or taxane therapy or recurrence within 6 months of completing platinum and/or taxane therapy), measurable disease, and performance status 0–2 were eligible and enrolled after giving informed consent. As guided by toxicity and pharmacokinetic data from single-agent phase I trials, PS-341 was administered on days 1, 4, 8, and 11 by IV push every 28 days with carboplatin (AUC 5) on day 1. Four dose levels were evaluated: 0.8, 1.0, 1.3, and 1.5 mg/m2. Dose was escalated if 0 of 3 or 1 of 6 patients had a DLT. The MTD was defined as 2 or more patients out of 6 with a DLT. Results: 21 women (median age 63, range 43–83), were treated with carboplatin and PS-341 at 0.8mg/ m2 (n=6), 1.0 mg/m2 (n=3), 1.3 mg/m2 (n=6), or 1.5 mg/m2. (n=6). At each level, respectively, there were 1, 0, 1, and 3 DLT’s attributable to PS- 341; all were grade 3, consisting of fatigue (n=3), nausea/vomiting/dehydration (n=1), and anorexia/dehydration/syncope (n=1). There were no Grade 4 toxicities. Common grade 2 toxicities included fatigue (n=12), nausea (n=10), anorexia, anemia, and dyspnea (n=7 each). 18 patients evaluable for response had stable disease (SD) or progression of disease (PD): at 0.8 mg/m2, SD=2, PD=3; at 1.0 mg/m2, PD=3; at 1.3 mg/m2, SD=3, PD=3; at 1.5 mg/m2, SD=3, PD=1. Median duration of stable disease was 4 months (range 3–10). Conclusions: The recommended dose of PS-341 in combination is 1.3 mg/m2. Treatment was well-tolerated with reversible side effects and no grade 4 toxicities, and at the optimal dose, there was a 50% rate of stable disease.

No significant financial relationships to disclose.

Use of a virtual human performance laboratory to improve integration of mathematics and biology in sports science curricula in Sweden and the United States

New fields such as bioengineering are exploring the role of the physical sciences in traditional biological approaches to problems, with exciting results in device innovation, medicine, and research biology. The integration of mathematics, biomechanics, and material sciences into the undergraduate biology curriculum will better prepare students for these opportunities and enhance cooperation among faculty and students at the university level. We propose the study of sports science as the basis for introduction of this interdisciplinary program. This novel integrated approach will require a virtual human performance laboratory dual-hosted in Sweden and the United States. We have designed a course model that involves cooperative learning between students at Göteborg University and Stanford University, utilizes new technologies, encourages development of original research and will rely on frequent self-assessment and reflective learning. We will compare outcomes between this course and a more traditional didactic format as well as assess the effectiveness of multiple web-hosted virtual environments. We anticipate the grant will result in a network of original faculty and student research in exercise science and pedagogy as well as provide the opportunity for implementation of the model in more advance training levels and K-12 programs.

Financial analysis of potential donor management at a medicare-approved transplant hospital

The purpose of this study was to perform a financial analysis of severe brain injured (SBI) patient management to determine potential reimbursement versus net losses in relation to organ donation and transplantation at a transplant center. We undertook a retrospective analysis of financial records of medically suitable referrals to the organ procurement organization (OPO) from our institution for fiscal years 2002-2003. This included (1) hospital cost and reimbursement, (2) OPO reimbursement for actual donors, (3) financial returns on local transplant activity solely supported by local donor activity and (4) Medicare incentives for local organ donation. There were 48 potential and 18 organ donors for this period. The consent rate reduced from 50% to 25% if family was offered withdrawal of care. After reimbursements from OPO, Medicare incentives and kidney transplant activity solely supported by local organ donation were figured in, the total returns were 244% of total cost of SBI patient management. Aggressive proactive management of severely brain injured patients remains a good medical practice. For Medicare-approved transplant centers, there are additional financial incentives to aggressively treat these patients and pursue organ donation. Prematurely offering withdrawal of care negatively impacts on the organ donation process and hurts institutions financially.

Changes in GABA(B) receptor mRNA expression in the rodent basal ganglia and thalamus following lesion of the nigrostriatal pathway

Loss of striatal dopaminergic innervation in Parkinson's disease (PD) is accompanied by widespread alterations in GABAergic activity within the basal ganglia and thalamus. Accompanying changes in GABA(B) receptor binding have been noted in some basal ganglia regions in parkinsonian primates, suggesting that plasticity of this receptor may also occur in PD. However, the molecular mechanisms underlying the changes in receptor binding and the manner and extent to which different GABA(B) receptor mRNA subunits and splice-variants are affected remain unknown. This study used in situ hybridisation to examine the full profile of changes in expression of the known rat GABA(B) receptor genes and gene variants in the basal ganglia and thalamus of rats, brought about by degeneration of the nigrostriatal tract. All of the GABA(B) mRNA species examined showed unique expression patterns throughout the basal ganglia and thalamus. In addition, all exhibited a marked loss of expression (between 46 and 80%) in the substantia nigra pars compacta of animals bearing a complete 6-hydroxydopamine-induced lesion of the nigrostriatal tract, confirming the presence of these variants in dopaminergic neurones in this region. Further analysis of autoradioagrams revealed additional changes only in GABA(B(1a)) mRNA in discrete anatomical regions. Expression of the GABA(B(1a)) variant was significantly increased in the substantia nigra pars reticulata (33+/-2%), entopeduncular nucleus (26+/-1%) and the subthalamic nucleus (16+/-1%). Since these regions all receive reduced GABAergic innervation following nigrostriatal tract lesioning, it is possible that the increased expression occurs as a compensatory measure. In conclusion, these data demonstrate that GABA(B) receptor genes exhibit regional- and subunit/variant-specific plasticity at the molecular level under parkinsonian conditions.

Characterization of cationic amino acid transporters and expression of endothelial nitric oxide synthase in human placental microvascular endothelial cells

We investigated the expression and activity of arginine transporters and endothelial nitric oxide synthase (eNOS) in human placental microvascular endothelial cells (HPMEC). Using RT-PCR amplification products for eNOS, CAT1, CAT2A, CAT2B, CAT4, 4F2hc (CD98), rBAT and the light chains y+LAT1, y+LAT2, and b0+T1 were detected in HPMEC, but not B0+. Immunohistochemistry and Western blotting confirmed the presence of 4F2hc and CAT1 protein in HPMEC. 4F2hc-light chain dimers were indicated by a shift in molecular mass detected under nonreducing conditions. L-Arginine transport into HPMEC was independent of Na+ or Cl- and was inhibited by the neutral amino acid glutamine, but not by cystine. The Ki for glutamine inhibition was greater in the absence of Na+. Kinetic analysis supported a two-transporter model attributed to system y+L and system y+. Expression of eNOS in HPMEC was detectable by immunohistochemistry and ELISA but not by Western blotting. Activity of eNOS in HPMEC, measured over 48 h, either as the basal production of nitric oxide (NO) or as the accumulation of intracellular cGMP was not detectable. We conclude that HPMEC transport cationic amino acids by systems y+ and y+L and that basal eNOS expression and activity in these cells is low.

Multiple renal arteries do not pose an impediment to the routine use of laparoscopic donor nephrectomy

Since the first description by Ratner and collegues in 1996, laparoscopic live-donor nephrectomy is gaining wide acceptance in an attempt to minimize the donor morbidity, length of hospital stay and length of time to return to work. It is unknown whether multiple renal arteries pose additional problems with laparoscopic donor nephrectomy. In November 1998, our institution initiated laparoscopic donor nephrectomy program. In the ensuing 19 months, we performed 25 living donor renal transplants, 24 of them using laparoscopic donor nephrectomy. The left kidney was procured in all cases. Eight donor candidates (33%) had two or more renal arteries (two arteries in five patients and three patients).

RESULTS

In six cases (25%), findings at surgery differed from the CT angography results (in four cases, CT angiogram reported fewer arteries than were found at surgery and in two cases it reported more). We found no significant differences in both donor outcomes and recipient, based on the presence or absence of multiple renal arteries. Among donor outcomes, we found equivalent results for donor warm ischemia time total donor operating time, and donor length of stay. For recipient outcomes, we found no significant differences between groups for the incidence of acute tubular necrosis (ATN), graft survival and most recent serum creatinine. In one case, we constructed two arteries into a single conduit on the backtable prior to transplantation. However, in most cases with multiple arteries, we implanted the arteries separately into the recipient external iliac artery. Based on this experience, we do not find the presence of multiple renal arteries to be a barrier to the successful use of kidney grafts procured by laparoscopic donor nephrectomy.

Nouns and verbs in Australian sign language: an open and shut case?

Results of the noun-verb pair comprehension and production tests from the Test Battery for Auslan Morphology and Syntax (Schembri et al., 2000) are re-presented, re-analyzed, and compared to data from two other cases also dealing with noun-verb pairs: the Auslan lexical database and a comparison of Auslan and American Sign Language (ASL) signs. The data elicited through the test battery and presented in this article confirm the existence of formationally related noun-verb pairs in Auslan in which the verb displays a single movement and the noun displays a repeated movement. The data also suggest that the best exemplars of noun-verb pairs of this type in Auslan form a distinct set of iconic (mimetic) signs archetypically based on inherently reversible actions (such as opening and shutting). This strong iconic link perhaps explains why the derivational process appears to be of limited productivity, though it does appear to have "spread" to a number of signs that appear to have no such iconicity. There appears to be considerable variability in the use of the derivational markings, particularly in connected discourse, even for signs of the "open and shut" variety. Overall, the derivational process is apparently still closely linked to an iconic base, is incipient in the grammar of Auslan, and is thus best described as only partially grammaticalized.

Innovative programs for children and adolescents with spinal cord injury

A few innovative programs have enabled children with SCI to surpass traditional levels of independence defined solely on preservation of motor function. Implementation of unique upper extremity and bladder surgical programs has provided children with tetraplegia the ability to manipulate objects without equipment and to independently empty their bladder, respectively. Innovative surgical programs have also restored privacy, dignity, and spontaneity. These are important gains previously unachievable by young persons with tetraplegia. Functional electrical stimulation has advanced children's abilities in upright mobility and has made significant impact on their quality of life by restoring hand and bladder capacities. Nurses play a leadership role in the delivery and integration of these dynamic programs.

Climate change and the adaptability of agriculture: a review

The assessment of climate change impacts on agriculture has emerged as a recognizable field of research over the past 15 years or so. In a relatively short period, this area of work has undergone a number of important conceptual and methodological developments. Among many questions that have been debated are the adaptability of agriculture to climate change and the importance of land management adjustments in reducing the adverse effects of climate change. In turn, this latter focus has spawned a discussion regarding the nature of adaptation and the ability of agriculture to respond to sudden and rapid climatic changes. In this paper we present an overview of this debate. It is argued that the first generation of climate change impact studies generally ignored the possibility that agriculturalists may adjust their farming practices in order to cope with climate change or to take advantage of new production opportunities. This conceptual oversight has been largely eliminated over the past five years or so. However, questions remain surrounding the likelihood that various adaptive strategies will actually be deployed in particular places. In this paper, we stress the importance of studying adaptation in the context of decision-making at the individual farm level and beyond.

Taxometric analysis of impression management and self-deception on the MMPI-2 in child-custody litigants

The typology of impression management (IM), a deliberate attempt to create a positive social image, and self-deceptive positivity (SDP), an unintentional concealment of symptoms, were examined using taxometric procedures with MMPI-2 (Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989) underreporting scales in several custody-litigant samples. IM was identified as a taxon using several procedures and estimates of the base rate that were consistent (.40, .37, .31, .36, .37). SDP was better characterized as a dimensional construct. Means and estimated validities for MMPI-2 underreporting scales in this sample are reported. IM and SDP appear to be distinct and measurable underreporting constructs on the MMPI-2.

High performance laser diode bars with aluminum-free active regions

We present operating and lifetest data on 795 and 808 nm bars with aluminum-free active regions. Conductively cooled bars operate reliably at CW power outputs of 40 W, and have high efficiency, low beam divergence, and narrow spectra. Record CW powers of 115 W CW are demonstrated at 795 nm for 30% fill-factor bars mounted on microchannel coolers. We also review QCW performance and lifetime for higher fill-factor bars processed on identical epitaxial material.

In vivo assessment of failed trophoblastic invasion of the spiral arteries in pre-eclampsia

OBJECTIVE

To assess the ability of colour/pulsed Doppler ultrasound to detect failed physiologic change of the spiral arteries in pregnancies complicated by pre-eclampsia.

DESIGN

Prospective matched-pairs case controlled study.

SETTING

Tertiary referral teaching hospital.

SAMPLE

Sixteen women with severe pre-eclampsia and 16 normotensive controls.

METHODS

Colour/pulsed Doppler assessment of blood flow in the uterine arteries and spiral arteries in central and peripheral parts of the placental bed.

MAIN OUTCOME MEASURES

Impedance to blood flow in the spiral arteries in pre-eclamptic group compared with normotensive controls.

RESULTS

In women with pre-eclampsia there is significantly higher impedance to blood flow in spiral arteries compared with normotensive women.

CONCLUSIONS

Ultrasound colour/pulsed Doppler based investigation of blood flow in the spiral arteries in ongoing pregnancy can detect failed physiological change of these vessels in pre-eclampsia. This is in concordance with histologic data.

Expect the worse or hope for the best? Prenatal diagnosis of geleophysic dysplasia

Geleophysic dysplasia is a rare, autosomal recessive disorder which causes disproportionate short stature associated with severe physical handicaps, but is compatible with survival into adulthood. We present a case, a first-born child, where genetic counselling difficulties arose following ultrasound recognition of short-limbed dwarfism in association with polyhydramnios and an initial incorrect prenatal diagnosis of lethal chondrodysplasia. After birth of the surviving affected infant, the parents had great difficulty accepting that there had been a prenatal misdiagnosis and they were greatly disappointed by our inability to predict the postnatal survival of an infant to whom no hope of life had previously been given. The correct diagnosis was not made until the proband was nearly 1 year old, and the true prognosis then became clearer. This experience underlines the relative ease of prenatal recognition of skeletal growth abnormalities compared with the considerable difficulties experienced in reaching a precise diagnosis. Thus, following prenatal diagnosis of unspecified chondrodysplasia when parents seek definite information about the prognosis, the temptation to be either overpessimistic or overoptimistic should be avoided.