bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Recombinant Equine Growth Hormone on In Vitro Biomechanical Properties of the Superficial Digital Flexor Tendon of Standardbred Yearlings in Training
Authors: Gerard Mathew P. , Hodgson David R. , Rose Reuben J. , Walsh William. R.
Published: August 2005

Objective—To determine whether recombinant equine growth hormone (rEGH) would alter the in vitro biomechanical properties of the forelimb superficial digital flexor tendon (SDFT) in exercising young Standardbred horses.

Study Design—Randomized complete block design.

Animals—Twelve Standardbred yearlings.

Methods—Horses were trained for 12 weeks on a high‐speed treadmill (10% positive incline). rEGH was administered intramuscularly (IM) daily (10 μg/kg during week 4; 20 μg/kg for weeks 5–9) to 6 horses (treated group), whereas 6 horses (control group) were administered an equivalent daily volume of sterile water IM. At 12 weeks, horses were euthanatized and left forelimb SDFTs were collected and stored (−70°C). A section from the mid‐region of the SDFT was held in cryoclamps with a 4 cm interspace distance and distracted at 10 mm/s until failure. The variables evaluated were maximal load at yield and failure, ultimate and yield tensile stress and strain, tendon stiffness, and mode of failure. Data were analyzed using unpaired, two‐tailed, Student's t‐test. Statistical significance was set atP≤.05.

Results—Yield and ultimate tensile stress were significantly lower in the rEGH‐treated horses compared with controls. There was a trend toward increased maximal displacement, increased ultimate tensile strain, and decreased tendon stiffness in rEGH‐treated horses compared with controls. Tensile stress and cross‐sectional area, and tensile stress and stiffness were significantly correlated at yield and failure points.

Conclusions—rEGH, administered at the manufacturer's recommended dose rates to maturing Standardbred horses in training, does not significantly augment the in vitro biomechanical properties of the forelimb SDFT.

Clinical Relevance—Administration of rEGH to young horses in training is unlikely to enhance the physiologic adaptation of the SDFT to exercise stress.
Laparoscopic Sterilization of Sardinia Donkeys Using an Endoscopic Stapler
Authors: Pepe Marco , Gialletti Rodolfo , Moriconi Franco , Puccetti Massimo , Nannarone Sara , Singer Ellen R.
Published: August 2005

Objective—To describe a laparoscopic technique for sterilization of the male donkey using an endoscopic linear stapler (ELS).

Study Design—Clinical report.

Animals—Male Sardinia donkeys (n=6), aged 24–36 months.

Methods—Laparoscopic sterilization was performed under standing sedation or recumbent under general anesthesia. An endoscopic linear stapler was used to transect, and control hemorrhage of, the spermatic cord. Serum testosterone concentrations were measured preoperatively and at 3, 6, and 12 months after sterilization. One testis from each of 2 donkeys was collected at 12 months for histologic examination.

Results—Sterilization was successfully achieved. The only minor intraoperative complication experienced was hemorrhage from 1 spermatic cord stump, which was re‐stapled. No other major short‐ or long‐term complications occurred. Serum testosterone concentrations were <15 ng/dL at 3, 6, and 12 months after surgery in all donkeys. Testicular atrophy without evidence of revascularization was observed in the 2 testes examined histologically.

Conclusions—Sterilization of descended testes by intraabdominal laparoscopic transection of the spermatic cord is a simple practical method, with minimal intraoperative or postoperative complications. Testicular revascularization did not occur.

Clinical Relevance—Laparoscopic sterilization in donkey can be performed using an endoscopic linear stapler as an alternative to scrotal castration.
Pre‐ and Postoperative Radiographic and Computed Tomographic Evaluation of Dogs with Medial Patellar Luxation
Authors: Towle Heather A. , Griffon Dominique J. , Thomas Michael W. , Siegel Arthur M. , Dunning Dianne , Johnson Ann
Published: August 2005

Objective— To quantify, using radiographic and computed tomographic (CT) techniques, the effects of surgical procedures most commonly combined to treat dogs with medial patellar luxation (MPL).

Study Design— Prospective study.

Methods— Six dogs with 8 MPL were studied. Radiographs and CT of the pelvic limbs were obtained before and immediately after soft‐tissue reconstruction, trochlear wedge recession, and tibial crest transposition. Radiographic measurements included angle of inclination, Norberg angle, quadriceps angle (QA), anteversion angle, ratio of the length of the patellar tendon (PT) to the length of the patella, and change in patella tendon angle. CT measurements included angle of inclination, Norberg angle, QA, anteversion angle, depth of the femoral trochlear groove, ratio of the middle femoral trochlear groove depth to the patella thickness, and tibial crest alignment.

Results— Conformation of the coxofemoral joint was not affected by surgery. Surgical treatment corrected the QA by 33–58%. Trochlear wedge recession was most effective in deepening the proximal trochlea by 103.5%. The ratio of the middle femoral trochlear groove depth to the thickness of the patella postoperatively resulted in 50% coverage of the patella. Tibial crest transposition resulted in caudalization of the PT by 8.5±3.0°, with lateralization of the tibial tuberosity of 11.3°.

Conclusion— The effects of surgery for MPL can be quantified with radiographic and CT measurements. Surgical correction restored the alignment of the quadriceps and adequately deepened the femoral trochlear groove. Tibial crest transposition resulted in caudalization of the patella tendon and lateralization of the tibial tuberosity.

Clinical Relevance— These pilot data quantified the effects of surgical procedures most commonly combined to treat MPL. We hope to use these measurements to correlate surgical treatment with functional outcome and postoperative occurrence of luxation.
Comparison of Postoperative Pain After Ovariohysterectomy by Harmonic Scalpel‐Assisted Laparoscopy Compared with Median Celiotomy and Ligation in Dogs
Authors: Hancock Robert B. , Lanz Otto I. , Waldron Don R. , Duncan Robert B. , Broadstone Richard V. , Hendrix Paula K.
Published: August 2005

Objective—To compare the effects of postoperative pain after ovariohysterectomy by harmonic scalpel‐assisted laparoscopy (HALO) and traditional ovariohysterectomy (OVH) in dogs.

Study Design—A randomized, blinded, prospective study.

Sample Population—Sixteen, purpose‐bred, intact female, Beagle dogs.

Methods—Dogs were divided into 2 groups: Group 1 (8 dogs), which had OVH by HALO, and Group 2 (8 dogs), which had traditional OVH. Physiologic data, abdominal nociceptive threshold scores, and University of Melbourne pain scores (UMPS) were recorded at 2, 6, 12, 24, 48, and 72 hours after surgery. Blood samples for measurement of plasma cortisol, glucose, and creatine phosphokinase (CPK) concentrations were collected at the time of the incision, and 2, 6, 12, 24, 48, and 72 hours after surgery.

Results—No significant surgical complications occurred. The HALO mean surgical time was significantly longer (55.7 minutes) than traditional OVH (31.7 minutes). No significant differences were observed between groups for the pain measures of heart rate, respiratory rate, temperature, CPK, and glucose concentrations. The OVH group had significantly higher mean plasma cortisol levels at hour 2 after surgery than the HALO group (P=.0001). The mean UMPS were significantly higher in OVH than the HALO group at all postoperative times (P=.0001). The mean nociceptive threshold measurements revealed significantly higher tolerated palpation pressures in HALO than OVH at all postoperative times, except hour 72 (P=.0002).

Conclusions—Dogs appeared to be in less pain with HALO than OVH. The harmonic scalpel coagulated ovarian and uterine vessels completely with minimal collateral damage to surrounding tissues.

Clinical Relevance—HALO is a safe alternative to OVH and offers a minimally invasive and less painful method of surgery.
In Vitro Evaluation of the 18 and 36 kg Securos Cranial Cruciate Ligament Repair System™
Authors: Banwell Max N. , Kerwin Sharon C. , Hosgood Giselle , Hedlund Cheryl S. , Metcalf John B.
Published: August 2005

Objective— To evaluate the mechanical properties of the 18 and 36 kg Securos Cranial Cruciate Ligament Repair System™.

Study Design— In vitro mechanical evaluation.

Sample Population— Loop constructs of 18, 27, and 36 kilogram test (kgt) nylon leader line (NLL) secured with Securos® crimp–clamps (SCC, n=40 per NLL test weight) or by a clamped square knot (CSK; n=40/NLL test weight).

Methods— The 36 kg SCC were used for the 27 and 36 kgt NLL, and 18 kg SCC were used for the 18 kgt NLL. Loop constructs were mounted on a material testing machine, and distracted at 500 mm/min for static tests, and for cyclic tests at 500 mm/min to a distraction limit of 6 mm (18 kgt) or 7.5 mm (27 and 36 kgt) for 49 cycles, until failure. Constructs were tested at 20°C except for 1 group of 27 kgt CSK loops tested at 40°C. Load at failure, elongation, and stiffness was recorded and compared between groups under static or cyclic testing conditions.

Results— All 27 and 36 kgt loops failed by disruption of NLL contained within the knot or crimp–clamp, whereas 18 kgt SCC loops failed by the NLL pulling through the crimp‐clamp. The 18 kg SCC loops had considerable variability in ultimate load and elongation (coefficient of variation 29.6% and 18.3%, respectively). There was no significant difference in elongation between 27.3 kgt CSK loops tested at 20°C and 40°C. Generally, in both static and cyclic testing, SCC constructs formed with 27.3 or 36.4 kgt NLL performed as well or better than CSK constructs, resulting in loops that were strong, underwent minimal elongation, and had high stiffness.

Conclusion— The results support use of the 36 kg Securos® system but not the 18 kg Securos® system (with the clamp and crimping device used). The significantly lower load required for failure, slippage through the clamp, and substantial variability suggested that the crimp tube diameter or the crimping device tested may be inappropriate for use with 18 kgt NLL.

Clinical Relevance— Surgeons should be aware that crimp–clamp design is important in controlling suture slippage or breakage within the clamp, and that novel systems should undergo mechanical testing with the size suture material they are intended to secure before clinical use.
Bursting Tension of Medium and Large Canine Arteries Sealed with Ultrasonic Energy or Suture Ligation
Authors: Bubenik Loretta J. , Hosgood Giselle , Vasanjee Sunil C.
Published: August 2005

Objective— To compare bursting tension of arteries ≥3 mm in diameter sealed with ultrasonic energy (UE) with arteries ligated with suture.

Study Design— Experimental, nested factorial design.

Sample Population— Vascular segments from canine cadavers.

Methods— Arterial segments (12) were collected from each of 16 canine cadavers and equally divided into 2 groups based on vessel diameter (medium, 3.0–<4.5 mm; large, 4.5 –≤6.0 mm). Arterial specimens (3) from each group were sealed with either UE (Harmonic Scalpel®, HS, power level 3) or suture ligation. The mean bursting pressure and tension were determined and compared.

Results— Bursting tension was significantly higher (P<.0001) for sutured arteries than UE‐occluded arteries, irrespective of size. Bursting tension was significantly higher (P=.0013) for medium than large UE‐occluded arteries, whereas there was no difference associated with size for ligated arteries. UE energy failed to seal 1 medium artery and 7 large arteries. Compared with normal blood pressure, bursting pressures were 3.5 times greater for sutured arteries irrespective of size, 1.8 times greater for medium UE‐occluded arteries, and approached normal blood pressure for large UE‐occluded arteries.

Conclusion— At the power level tested, UE should not be used to seal arteries >4.5 mm in diameter. Suture provided an optimal seal for arteries ≤6.0 mm in diameter.

Clinical Relevance— Use of UE to occlude arteries during laparoscopic surgery is advantageous because only 1 instrument is required to simultaneously cut and coagulate tissue, but care should be exercised where large arteries might be encountered.
Assessment of Stiffness and Strength of 4 Different Implants Available for Equine Fracture Treatment: A Study on a 20° Oblique Long‐Bone Fracture Model Using a Bone Substitute
Authors: Florin Marion , Arzdorf Michael , Linke Berend , Auer Joerg A.
Published: August 2005

Objective— To compare the mechanical properties of 4 stabilization methods for equine long‐bone fractures: dynamic compression plate (DCP), limited contact‐DCPlate (LC‐DCP), locking compression plate (LCP), and the clamp‐rod internal fixator (CRIF—formerly VetFix).

Study Design— In vitro mechanical study.

Sample Population— Bone substitute material (24 tubes) was cut at 20° to the long axis of the tube to simulate an oblique mid‐shaft fracture.

Methods— Tubes were divided into 4 groups (n=6) and double plated in an orthogonal configuration, with 1 screw of 1 implant being inserted in lag fashion through the “fracture”. Thus, the groups were: (1) 2 DCP implants (4.5, broad, 10 holes); (2) 2 LC‐DCP implants (5.5, broad, 10 holes); (3) 2 LCP implants (4.5/5.0, broad, 10 holes) and 4 head locking screws/plate; and (4) 2 CRIF (4.5/5.0) and 10 clamps in alternating position left and right of the rod. All constructs were tested in 4‐point bending with a quasi‐static load until failure. The implant with the interfragmentary screw was always positioned on the tension side of the construct. Force, displacement, and angular displacement at the “fracture” line were determined. Construct stiffness under low and high loads, yield strength, ultimate strength, and maximum angular displacement were determined.

Results— None of the implants failed; the strength of the bone substitute was the limiting factor. At low loads, no differences in stiffness were found among groups, but LCP constructs were stiffer than other constructs under high loads (P=.004). Ultimate strength was lowest in the LCP group (P=.01), whereas yield strength was highest for LCP constructs (409 N m, P=.004). CRIF had the lowest yield strength (117 N m, P=.004); no differences in yield strength (250 N m) were found between DCP and LC‐DCP constructs. Differences were found for maximum angular displacement at the “fracture” line, between groups: LPC<DCP<LC‐DCP<CRIF (P≤.037).

Conclusions— DCP, LC‐DCP, and LCP constructs provided sufficient biomechanical stability to withstand single‐cycle loads that might be experienced postoperatively. LCP constructs showed the best performance because of the highest yield strength, above which irreversible deformation occurred. Inadequate biomechanical properties, excessive motion, and shape of the device create concern about the use of CRIF in these large sizes.

Clinical Relevance— CRIF does not meet the demands for equine long‐bone fracture treatment. With respect to biomechanical properties, DCP, LC‐DCP, and LCP constructs did not show critical differences so other factors may direct clinical selection of these implants. We prefer the LCP implants because of the high yield strength, high stiffness under high‐load application, and the least movement at the fracture line.
Role of respiratory system function in the age‐related decline of human functional capacity
Authors: Pine Matthew J , Murphy Aron J , Watsford Mark L
Published: August 2005

Objective:  To examine the age‐related decline of physical and respiratory system function in older individuals.

Methods:  Using a cross‐sectional research design, 36 healthy participants were assigned to group A (50–59 years) or group B (60–69 years). Males (n = 14) and females (n = 22) were examined separately. Physical capacity was determined using a combination of two walking tests. Measures of pulmonary function, respiratory muscle (RM) strength and inspiratory muscle endurance (IME) were used to assess respiratory system function.

Results:  Significant age‐related declines in RM strength, IME and walking ability were apparent for females, but not males. An increase in age was associated with less efficient breathing mechanics during exercise.

Conclusions:  The more substantial age‐related declines in RM and physical function for females may be related to greater age‐related reductions in physical activity participation. As individuals are living for increasingly longer periods, the continuance of such declines may significantly impair quality of life. Methods of overcoming respiratory system decline and the role of such methods in maintaining the physical capacity of ageing individuals require investigation.
Environmental approach to reducing agitation in older persons with dementia in a nursing home
Authors: Wilkes Lesley , Fleming Andrew , Wilkes Benjamin L , Cioffi Jane M , Le Miere Jenny
Published: August 2005

Objective:  This paper reports the effects on challenging (agitated) behaviours, such as aggression, noisiness and wandering, when persons with dementia were relocated to a special unit.

Methods:  The study was a simple interrupted time series quasi‐experimental design. The dependent variable was agitated behaviour and the independent variables were residing in an old unit and in a Special Care Unit (SCU). Twenty‐two persons with dementia from a nursing home were involved in this study. Subjects were assessed weekly for 1 month prior to the move to the SCU and weekly for 1 month at 3 and 6 months after the move. Data were entered into SPSS software and analysed.

Results:  The most significant results from the study were that the verbally agitated behaviour of the subjects was reduced and sustained throughout the 6 months of the study after their move into a SCU.

Conclusions:  This study has shown that environmental design does impact positively in the care of persons with dementia.
Language needs and service provision for older persons from culturally and linguistically diverse backgrounds in south‐east Melbourne residential care facilities
Authors: Runci Susannah J , O'Connor Daniel W , Redman Jennifer R
Published: August 2005

Objectives:  To provide up‐to‐date figures on the language needs of older persons from culturally and linguistically diverse (CALD) backgrounds in local residential care facilities and to investigate the extent to which these needs are catered for by the provision of language‐relevant services.

Methods:  A postal questionnaire was sent to 189 registered aged care facilities in the south‐east region of Melbourne, Victoria. The questionnaire focused on three main issues: the number of residents who preferred or needed to speak non‐English languages; the staff available to speak to residents in non‐English languages; and the language‐specific services provided at their facility.

Results:  As many as 19% (1191/6409) of residents either preferred or needed to speak one of 40 different non‐English languages. While over half of the facilities had at least one staff member who conversed with residents in their preferred language, residents speaking nine non‐English languages were never spoken to in their original tongue. Almost one‐quarter of the facilities did not provide any language‐relevant services.

Conclusion:  The findings emphasise the need for widespread use of language‐appropriate services and, due to the growing ageing migrant population, have important policy implications.
Quality project to prevent delirium after hip fracture
Authors: Wong Tin Niam Dorothy M , Bruce Jennifer J , Bruce David G
Published: August 2005

Objectives:  It has been demonstrated that a series of strategies supervised by a geriatrician can reduce the incidence of delirium in elderly hip fracture patients. The aims of this project were to determine if a geriatric registrar could introduce these strategies and alter the incidence of delirium in our orthopaedic unit.

Methods:  The program used quality improvement methods and included staff education and the use of a checklist to facilitate the use of the strategies. We counted the number of recommendations made, the subsequent adherence to the recommendations and the before and after monthly incidence of delirium.

Results:  The geriatric registrars made 424 recommendations (average six per patient) during a 3‐month intervention period, of which 89.9% were adhered to. Baseline data indicated an incidence of delirium of 10/28 cases (35.7%). Following introduction of the strategies, subsequent monthly incidences of delirium were 4/28 cases (14.3%), 3/22 cases (13.6%) and 2/21 cases (9.5%) (P < 0.035 compared with baseline).

Conclusions:  We conclude from this short program that methods proven to prevent delirium can be introduced into routine clinical practice and that this appears to prevent cases of delirium.
Grandparents parenting their grandchildren
Authors: Orb Angelica , Davey Margaret
Published: August 2005

Objectives:  This study aims to describe the perceptions of grandparents parenting their grandchildren on full‐time bases.

Method:  The paper uses a descriptive qualitative approach to depict grandparents’ parental experience. Seventeen grandparents, including four couples, were interviewed. Data were analysed and interpreted using content analysis.

Results:  The findings indicated that grandparents parenting their grandchildren found that this unexpected role brought several emotional, social and financial problems into their lives. They actively looked for resources that could provide them with support to overcome the stressors of their parental role. Many expressed concerns about the future of their grandchildren and frustration when they were dealing with government institutions.

Conclusion:  A number of important areas are identified that have policy implications.
Benchmarking the living standards of older Australians using budget standards
Authors: Saunders Peter , Patulny Roger , Lee Adeline
Published: August 2005

Objectives: To demonstrate how a budget standards framework can provide valuable information on the income needed by older Australians to attain a specific standard of living in retirement.

Methods: A budget standard is derived by specifying the items required to achieve a specific standard of living and pricing them to estimate how much is needed to buy them. This paper updates earlier estimates and develops a new comfortably affluent but sustainable (CAS) budget that represents the lifestyles and aspirations of self‐funded retirees. Initial updating was in line with movements in the consumer price index, followed by revisions guided by data on actual expenditure patterns and by three sets of focus group interviews with 21 people aged between 61 and 76 years.

Results: The low cost standard for a 70‐year‐old women living alone in September 2003 was $253 a week. The modest but adequate standard is $330 a week, while the new CSA standard is $611 a week.

Conclusions: The paper demonstrates that employing both quantitative and qualitative dimensions is necessary to give credibility to the complex task of estimating the income needed to attain a specific standard of living.
Patterns and predictors of nursing home placement over 14 years: Dubbo study of elderly Australians
Authors: McCallum John , Simons Leon A , Simons Judith , Friedlander Yechiel
Published: August 2005

Objective:  To describe patterns and predictors of nursing home placement.

Methods:  This is a longitudinal study of an elderly cohort living in Dubbo, New South Wales, Australia. A total of 1233 men and 1572 women aged 60 years and older living in the community were examined in 1988 and followed for 14 years. The incidence of nursing home placement and underlying clinical diagnoses were assessed. Results were modelled for baseline predictors of placement using Cox proportional hazards regression.

Results:  From 2805 subjects in the study there were 244 (8.7%) nursing home placements, 95 in men (7.7%) and 149 in women (9.5%). A total of 44% placements were primarily due to dementia, but dementia was a secondary diagnosis in another 20% of cases. The other principal diagnoses were stroke (16%) and coronary heart disease (14%). Median time to death in a nursing home was 10.5 months in men and 9.0 months in women. In a Cox proportional hazards model using baseline characteristics, the hazard of nursing home placement increased significantly with age (hazard ratio = 1.13), urinary incontinence (1.66), impaired peak expiratory flow (3.19), physical disability (1.59) and depression (1.85). The hazard of placement was significantly reduced by alcohol intake (0.55) and female gender (0.55). Socioeconomic factors were not significant.

Conclusions:  Dementia and disability‐related care burdens rather than other health conditions are the dominant causes of nursing home placement in an unselected elderly community. Risk factors such as incontinence, impaired respiratory function and depression have been identified and these are potentially amenable to intervention.
Adult day groups: addressing older people's needs for activity and companionship
Authors: Tse Tamara , Linsey Howie
Published: August 2005

Objective: Adult day groups (ADGs) are used by older adults living at home in the community in Australia. Their aim is to prevent social isolation and to maintain independence through supporting social networks and providing a program of activities that enhance the physical, intellectual and social well‐being of the participants and carers. The purpose of this study was to examine the experience of and reasons why older people attend ADGs.

Methods: An ethnographic study of four ADGs in Victoria, Australia was conducted over a 4‐month period. The study included observation of the four ADGs and interviews with eight clients, comprising five women and three men.

Findings: Four major themes were derived from data analysis. The first was related to the importance of companionship with staff and clients of the ADGs. The second revealed how participants valued keeping occupied in activities not achievable at home, while the third identified how home was experienced as a place where time passed slowly and there were insufficient things to do. Lastly, participants identified dissatisfactions with ADGs.

Conclusion: Community based programs that foster companionship and meaningful and purposeful occupations in older age are desirable. Improvements to ADGs to better meet the occupational and activity needs of older people living at home are suggested.
Comparative analysis of food‐finding behavior of an herbivorous and a carnivorous land snail
Authors: Shearer Alyssa , Atkinson James W.
Published: August 2005

Abstract. Although the olfactory capabilities of land snail tentacles have been tested by lesion studies and unilateral exposure of tentacles to specific odors, studies of a carnivorous species suggest that the anatomical similarities of herbivorous and carnivorous land snails may belie a fundamental difference in the way these structures are used to find food. Therefore, we challenged the herbivore, Anguispira alternata, and the carnivore, Haplotrema concavum, to find a stationary food source (carrot and caged young prey snail, respectively) under identical still air conditions. The herbivore traveled a significantly shorter distance to the food, even negotiating a barrier placed halfway between the snail and its food. The carnivore, on the other hand, followed a circuitous, apparently random, path to the food. Subsequent tests revealed that H. concavum readily follows prey slime trails while A. alternata seldom follows conspecific slime trails when a distant food source is available. These results are consistent with what might be expected as adaptations to the usually mobile nature of carnivore prey and the stationary nature of herbivore food plants. The ability of A. alternata to exhibit typical detour behavior is noted.
Neurocalcin‐like immunoreactivity in embryonic stages of the gastropod molluscs Aplysia californica and Lymnaea stagnalis
Authors: Dickinson Amanda J.G. , Croll Roger P.
Published: August 2005

Abstract. Neurocalcin is a calcium‐binding protein that has been localized in neural and non‐neural tissues of vertebrates, the arthropod Drosophila melanogaster, and in juveniles and adults of the mollusc Aplysia californica. We examine the distribution of neurocalcin in pre‐hatching stages of the molluscs A. californica and Lymnaea stagnalis to elucidate where this calcium‐binding protein functions in early development, as well as to localize novel neuronal populations in early stages of ontogeny. Aplysia neurocalcin (ApNc)‐like immunoreactivity was localized in shell‐secreting cells in embryonic stages of both A. californica and L. stagnalis. In A. californica, central and anterior regions of the embryo were diffusely labeled, as were a few identifiable neurons in veliger stages, On the other hand, in L. stagnalis, ApNc‐like immunoreactivity was clearly detected in cells and fibers in the same locations as neuronal elements that have been previously identified very early in development and throughout the embryonic period using techniques to localize specific transmitters and peptides. Furthermore, additional neurons are also identified with anti‐ ApNc in this species. Establishing the distribution of neurocalcin‐like proteins in embryonic stages of these two molluscs provides the first step to understanding the role of such proteins during development.
The spermatheca in the land snail, Arianta arbustorum (Pulmonata: Stylommatophora): muscle system and potential role in sexual selection
Authors: Bojat Nenad C. , Dürrenberger Markus , Haase Martin
Published: August 2005

Abstract. Previous studies have shown variable patterns of paternity after multiple mating, and also variation in sperm storage among individuals of Arianta arbustorum, which suggests that the spermatheca may influence paternity in this promiscuous land snail. To identify possible morphological correlates of sperm manipulation, we investigated arrangement and ultrastructure of the muscles of the spermatheca. The musculature surrounding the 2–9 spermathecal tubules is arranged in a complex three dimensional network. In addition, each tubule has a thin sheath in which longitudinally oriented cells make up the innermost layer. Usually, the smooth muscle cells are enclosed by connective tissue. Only occasionally is direct muscle‐muscle contact established through dense plaques. The short thick filaments, their small diameter, the relatively weak development of the tubular system and sarcoplasmic reticulum, and the low density of mitochondria indicate that the muscle cells contract relatively fast but with little strength, that they recover slowly, and have low endurance. A single muscle cell may be innervated by several axons and one axon may contact several muscle cells. Combining evidence of the present paper and a foregoing investigation on the spermathecal epithelium, we suggest that the main function of the spermathecal muscles is to expel sperm stored for fertilization, while the ciliation of the common duct is probably responsible for the distribution of sperm among the tubules.
Ultrastructural evidence for nutritional exchange between brooding unionid mussels and their glochidia larvae
Authors: Schwartz Megan L. , Dimock Ronald V.
Published: August 2005

Abstract. The life history of unionid bivalve molluscs includes retention of developing embryos within the gills of parental mussels. This brooding behavior may facilitate nutrient transfer to the glochidia larvae, i.e., matrotrophy. To address this possibility, morphological relationships between brood chambers and developing larvae of Pyganodon cataracta and Utterbackia imbecillis were examined with TEM, and larval shells were observed with SEM, for features that could be associated with the uptake of dissolved materials. Early in brooding, glochidia are enclosed in a vitelline membrane that physically contacts numerous cilia and microvilli of the epithelial cells lining the brood chamber (marsupium). The vitelline membrane subsequently disappears. Lamellar tissues of parental mussels initially have large deposits of glycogen that diminish during the course of brooding. Septa separating brood chambers from adjacent secondary water tubes have numerous mitochondria and microvilli, suggesting the potential for active transport of materials into or out of the marsupia. Since punctae (pores) in the larval shells become filled with an organic matrix early in brooding, they are unlikely to be involved in nutrient exchange. Ultrastructure of the brood chamber and physical contact between the parental mussel and larvae are consistent with a nutritive role for retention of glochidia in the marsupia.
Reproduction and larval development of Polydora robi (Polychaeta: Spionidae), an obligate commensal of hermit crabs from the Philippines
Authors: Williams Jason D.
Published: August 2005

Abstract. The reproduction of a recently described spionid polychaete, Polydora robi, is examined from the Philippines. Adults inhabit a burrow in the apex of gastropod shells occupied by hermit crabs. Females were found to deposit broods of 18–94 egg capsules in the summer (June–August) and winter months (January–March) sampled. Paired or single egg capsules are attached by stalks to the inside wall of the burrow and contain 40–106 eggs which average 97 μm in diameter. The total number of eggs per brood ranges from 941–8761 eggs and is positively correlated with the total number of segments and length of female worms. Adults of P. robi are polytelic, producing ≤9 successive broods over a 3‐month period; a mean of 6.7 d was exhibited between broods in the laboratory. Females utilize sperm stored in the seminal receptacles during successive spawnings. Development occurs within egg capsules until the 3‐segment stage, at which time the planktotrophic larvae are released. Juveniles of ∼20 segments are competent to settle on gastropod shells inhabited by hermit crabs. Members of P. robi are relatively fecund, semicontinuous breeders; the life‐cycle in this species is similar to the only other known obligate polydorid commensal of hermit crabs.
Behavioral plasticity and central regeneration of locomotor reflexes in the freshwater oligochaete, Lumbriculus variegatus. I: Transection studies
Authors: Lesiuk Nalena M. , Drewes Charles D.
Published: August 2005

Abstract. Access to the ventral nerve cord in living specimens of Lumbriculus variegatus, an aquatic oligochaete, is normally impossible because surgical invasion induces segmental autotomy (self‐fragmentation). We show here that nicotine is a powerful paralytic agent that reversibly immobilizes worms, blocks segmental autotomy, and allows experimental access to the nerve cord. Using nicotine‐treated worms, we transected the ventral nerve cord and used non‐invasive electrophysiological recordings and behavioral analyses to characterize the functional recovery of giant nerve fibers and other reflex pathways. Initially, after transection, medial giant fiber (MGF) and lateral giant fiber (LGF) spikes conducted up to, but not across, the transection site. Reestablishment of MGF and LGF through‐conduction across the transection site occurred as early as 10 h (usually by 20 h) after transection. Analyses of non‐giant‐mediated behavioral responses (i.e., helical swimming and body reversal) were also made following nerve cord transection. Immediately after transection, functional reorganization of touch‐evoked locomotor reflexes occurred, so that the two portions of the worm anterior and posterior to the transection site were independently capable of helical swimming and body reversal responses. Similar reorganization of responses occurred in amputated body fragments. Reversion back to the original whole‐body pattern of swimming and reversal occurred as early as 8 h after transection. Thus, functional restoration of the non‐giant central pathways appeared slightly faster than giant fiber pathways. The results demonstrate the remarkable plasticity of locomotor reflex behaviors immediately after nerve cord transection or segment amputation. They also demonstrate the exceptional speed and specificity of regeneration of the central pathways that mediate locomotor reflexes.
Behavioral plasticity and central regeneration of locomotor reflexes in the freshwater oligochaete, Lumbriculus variegatus. II: Ablation studies
Authors: Lesiuk Nalena M. , Drewes Charles D.
Published: August 2005

Abstract. After 8–10 segments of posterior ventral nerve cord were ablated in Lumbriculus variegatus, touch‐evoked locomotor responses were evident both in segments anterior and posterior to the ablation site. However, responses in these two regions were independent and uncoupled. During recovery, four outcomes were observed at the ablation site: (Group 1) recovery of normal functions with no growth of new segments; (Group 2) formation of a laterally protruding, multi‐segmented, ectopic head; (Group 3) formation of a laterally protruding, amorphous, and multi‐segmented outgrowth; and (Group 4) segmental autotomy. In Groups 1 and 2, touch‐evoked swimming and body reversal were studied. In addition, sensory fields and conduction properties of giant nerve fibers were examined near the ablation site. In some Group 1 worms, clear‐cut behavioral and electrical signs of recovery and reconnection were seen by 3 d after ablation. By 8 d, all worms had recovered and exhibited response patterns comparable to those of normal worms. In Group 2 worms, with an ectopic head, segments posterior to the ablation (together with those in the ectopic head), exhibited touch‐evoked swimming and body reversal responses resembling those of a complete worm. Segments anterior to the ectopic head were independently capable of locomotor responses. Medial and lateral giant fiber sensory fields in worms with ectopic heads reflected a pattern expected for two worms. Thus, through apparent morphallactic reorganization, a medial giant fiber sensory field emerged which included the ectopic head and 10–15 adjacent posterior segments. In contrast, electrical recordings showed longitudinal through‐conduction of giant fiber spikes, across the ablation site. Histological examination revealed that the giant nerve fibers in the ectopic head were complexly interconnected with those in the main body axis.
Copepods of the genus Asterocheres (Copepoda: Siphonostomatoida) feeding on sponges: behavioral and ecological traits
Authors: Mariani Simone , Uriz Maria‐J.
Published: August 2005

Abstract. Four copepod species of the genus Asterocheres (A. echinicola, A. latus, A. suberitis and A. complexus) are recorded for the first time as associated with Mediterranean sponges of the classes Calcarea and Demospongiae (orders Dictyoceratida, Dendroceratida, and Poecilosclerida). Individuals of A. suberitis are described for the first time as inhabiting sponges other than Suberites domuncula. The copepods seemed to use their trunk to suck the material (cuticles or excreted cells) produced at the sponge periphery (ectosome), which indicates that their feeding habits are similar to those observed in species of the same genus that feed on exfoliated tissues of echinoderms. In the laboratory, copepods fed on young sponges (rhagons) of the species Crambe crambe, Cacospongia mollior, and Dysidea avara without reducing the rhagon biomass. In contrast, rhagons of the species Haliclona sp., Hymedesmia spp., and Phorbas tenacior were consumed and their biomass reduced. This may be because the latter group does not produce external proteinaceous material. Copepod offspring were continuously released (∼6 nauplii every 48 h) and the larval stages were capable of limited swimming. We found significantly more copepods over the surface of the sponges than inside them. Copepod abundance was positively correlated with the sponge surface area while not with the sponge biomass. These results indicate that the copepods live preferentially over the sponge surface and that their abundance is surface‐area dependent. The behavioral traits described here indicate that the interactions between asterocherid species and sponges are worthy of future study.
Gut ultrastructure of the appendicularian Oikopleura dioica (Tunicata)
Authors: Burighel Paolo , Brena Carlo , Martinucci Gian Bruno , Cima Francesca
Published: August 2005

Abstract. The appendicularians, planktonic tunicates, possess a specialized, external filtering system that captures food particles <1 μm in size. In this work the alimentary canal of Oikopleura dioica has been studied by serial sections of whole animals and ultrastructure. The gut includes a dorsal esophagus, a bilobed saccular stomach, and a curved intestine, divided into vertical, mid‐, and distal intestine (or rectum). No multicellular glands or cellular proliferative centers were found. Three main cell types were recognized, ciliated microvillar cells, globular cells and gastric band cells, with specializations reflecting different physiological roles in the various regions. Ciliated microvillar cells, the most diffuse, are considered to be involved in food propulsion, fecal pellet formation, absorption, and nutrient storage. Pinocytotic features and vacuoles suggest that absorption of macromolecules and intracellular digestion occur in the globular cells of the stomach and rectum. The large gastric band cells of the left lobe have typical features of intense protein synthesis and probably produce enzymes for extracellular digestion. Diffuse interdigitations of many cells enormously increase the plasmalemma surface and may be involved in liquid/ion exchange. Despite the apparent structural simplicity of the gut epithelium, O. dioica efficiently processes food to fulfill the energy requirements of its exceptionally rapid life‐cycle.
Food plaquette digestion in the ciliated protozoan Hyalophysa chattoni
Authors: Landers Stephen C. , Treadaway Rex A. , Johnson Jason W. , Luckie Rebecca N.
Published: August 2005

Abstract. The digestion of food plaquettes in the ciliated protozoan Hyalophysa chattoni was analyzed by light and electron microscopy. Through the use of nigrosin as a tracer for light microscopy and polystyrene microparticles for electron microscopy, we have demonstrated that food plaquettes transform to late‐stage digestive vesicles. Eventually, in the phoront, some of the late‐stage vesicles merge to form larger fusion vesicles, which are retained in the peripheral cytoplasm of the ensuing feeding stage. After the feeding stage settles and encysts, these vesicles are either retained by the daughter cells or are left in the divisional cyst as residual bodies. Food plaquettes, digestive vesicles, and fusion vesicles stain positively with neutral red and acridine orange, indicating an acidic pH. These results portray a unique digestive pathway in which stored, undigested material is reorganized into larger fusion vesicles as the cell prepares for additional feeding.
Temperate and tropical algal‐sea anemone symbioses
Authors: Muller‐Parker Gisèle , Davy Simon K.
Published: August 2005

Abstract. In this review, we seek to develop new insights about the nature of algal‐sea anemone symbioses by comparing such associations in temperate and tropical seas. Temperate seas undergo pronounced seasonal cycles in irradiance, temperature, and nutrients, while high irradiance, high temperature, and low nutrients are seasonally far less variable in tropical seas. We compare the nature of symbiosis between sea anemones (= actinians) and zooxanthellae (Symbiodinium spp.) in both regions to test tropical paradigms against temperate examples and to identify directions for future research. Although fewer anemone species are symbiotic in temperate regions, they are locally dominant and ecologically important members of the benthic community compared to the tropics.

Zooxanthella densities tend to be lower in temperate anemones, but data are limited to a few species in both temperate and tropical seas. Zooxanthella densities are far more stable over time in temperate anemones than in tropical anemones, suggesting that temperate symbioses are more resistant to fluctuations in environmental parameters such as irradiance and temperature. Light‐saturated photosynthetic rates of temperate and tropical zooxanthellae are similar, but temperate anemone hosts receive severely reduced carbon supplies from zooxanthellae during winter months when light is reduced. Symbiont transmission modes and specificity do not show any trends among anemones in tropical vs. temperate seas.

Our review indicates the need for the following: (1) Investigations of other temperate and tropical symbiotic anemone species to assess the generality of trends seen in a few “model’ anemones. (2) Attention to the field ecology of temperate and tropical algal‐anemone symbioses, for example, how symbioses function under seasonally variable environmental factors and how zooxanthellae persist at high densities in darkness and winter. The greater stability of zooxanthella populations in temperate hosts may be useful to understanding tropical symbioses in which bleaching (loss of zooxanthellae) is of major concern. (3) Study of the evolutionary history of symbiosis in both temperate and tropical seas. Continued exploration of the phylogenetic relationships between host anemones and zooxanthella strains may show how and why zooxanthellae differ in anemone hosts in both environments.
Macrodasyida (Gastrotricha): a cladistic analysis of morphology
Authors: Hochberg Rick , Litvaitis Marianne K.
Published: August 2005

Abstract. A cladistic analysis based on 33 morphological characters was performed for the 31 genera currently assigned to the order Macrodasyida (Gastrotricha). Outgroup analysis indicated that the order is monophyletic and that it is defined by the structure of the pharynx and the complex distribution of duo‐gland adhesive organs. Of the 6 currently recognized families in Macrodasyida, our analysis confirmed that 4 families are monophyletic: Dactylopodolidae, Macrodasyidae, Thaumastodermatidae and Turbanellidae. Dactylopodolidae was further confirmed as the most basal family within the order based on the retention of several plesiomorphies. The other three families have well‐defined autapomorphies but will require further investigation to increase inter‐ and intrafamilial phylogenetic resolution. Planodasyidae appeared to be a paraphyletic taxon with no obvious autapomorphies; genera clustered among members of a polyphyletic family, Lepidodasyidae. We recommend that future research on macrodasyidan phylogeny focus on issues of comparative morphology and ultrastructure in lesser‐known taxa such as the Dactylopodolidae, and on the taxa Lepidodasyidae and Planodasyidae.
A carnivorous bdelloid rotifer, Abrochtha carnivora n.sp.
Authors: Ricci Claudia , Melone Giulio , Walsh Elizabeth J.
Published: August 2005

Abstract. Here we describe a new bdelloid rotifer, Abrochtha carnivora n.sp., that preys on other bdelloids and monogonont rotifers. This is the first report of predatory behavior in bdelloids. Despite this extraordinary behavior, A. carnivora displays no major structural deviation from the standard body plan for members of the bdelloid family Philodinavidae: body with head (with ciliated corona), trunk, and foot, mastax with ramate trophi. The finding of such a carnivorous species, unique for the class, appears to contradict the common assumption that the wholly parthenogenetic bdelloids are evolutionary dead‐ends.