bluuebunny/crossref_metadata_2025 huggingface dataset:
We've Come a Long Way—Maybe: New Challenges for Gender Equity in Education
Authors: Spencer Renée , Porche Michelle V. , Tolman Deborah L.
Published: November 2003

The purpose of this study was to examine the relationship between school-wide gender equity efforts and seventh grade girls’ and boys’ educational outcomes and psychological functioning. In this paper, we detail the components of the study, which included documenting that this school did in fact have a gender equitable environment; measuring students’ perceptions of gender equity in their school experience, academic achievement, self-esteem, and gender ideologies; and conducting classroom observations, focus groups, and individual interviews with a subset of this sample. Our findings from these efforts yielded an unexpected and intriguing contradiction. Overwhelmingly, teachers and students reported in surveys that they perceived their school to be gender fair. Yet classroom observations and interviews with students bring into view serious differentials in how boys and girls experienced, behaved and were treated in their classrooms. The students read these differences in classroom behaviors as reflecting inherent or natural differences between boys and girls; thus, these differences were experienced as equitable. The article concludes with a discussion of how these findings raise questions about, and issue challenges for, current conceptions of gender equity in schools.
Foreign Direct Investment, Technology Sourcing and Reverse Spillovers
Authors: Driffield Nigel , Love James H.
Published: November 2003

Recent theoretical work points to the possibility of foreign direct investment motivated not by ‘ownership’ advantages which may be exploited by a multinational enterprise but by the desire to access the superior technology of a host nation through direct investment. To be successful, technology sourcing foreign direct investment hinges crucially on the existence of domestic‐to‐foreign technological externalities within the host country. We test empirically for the existence of such ‘reverse spillover’ effects for a panel of UK manufacturing industries. The results demonstrate that technology generated by the domestic sector spills over to foreign multinational enterprises, but that this effect is restricted to relatively research and development intensive sectors. There is also evidence that these spillover effects are affected by the spatial concentration of industry, and that learning‐by‐doing effects are restricted to sectors in which technology sourcing is unlikely to be a motivating influence.
Aerobic Exercise and Plasma Beta Endorphin Levels in Patients with Migrainous Headache Without Aura
Authors: Köseoglu E , Akboyraz A , Soyuer A , Ersoy Aö
Published: November 2003

This study aims to evaluate the effects of plasma beta endorphin level and exercise on migrainous headache. Forty patients with migrainous headache without aura (MWOA), firstly exercised on a treadmill and afterwards were asked to continue an aerobic home exercise program for six weeks. On evaluation, basal plasma beta endorphin level was negatively correlated with total duration of attacks in the last month period ( P = 0.01). Exercise was found to have beneficial effects on all migraine parameters ( P < 0.0001) and to increase beta endorphin levels after the treadmill practice ( P < 0.0001) and after the home exercise program except four patients not regularly attended to the program ( P < 0.0001). Any of the changes in headache parameters was not correlated with the change in beta endorphin level. However, pre-exercise beta endorphin level was found to be negatively correlated with the changes in the number of attacks ( P < 0.05) and total duration of attacks ( P = 0.01) and also with the change in beta endorphin level due to exercise ( P < 0.0001). As a result, this study emphasizes the beneficial effect of exercise on migrainous headache, especially in patients with lower basal beta endorphin level.
Staff who Work with People who have Intellectual Disabilities: The Importance of Personality
Authors: Rose John , David Gareth , Jones Christopher
Published: November 2003

Background Previous research into stress in staff who work with people with intellectual disabilities has concentrated on the organizational determinants of stress and has tended to overlook the relative contribution of individual differences. A model was proposed to describe possible relationships between work‐based stressors, staff support, personality, coping strategy and psychological outcome.

Methods A survey methodology was used with care staff in community‐based homes for people with intellectual disability.

Results Analysis of the model explored how these variables might affect one another in their relationship to psychological outcomes. The most significant findings of this research was the direct effects found between personality (neuroticism), coping style (wishful thinking) and stress. A significant interaction was also observed between job demands and neuroticism.

Conclusions These research findings highlight the importance of personality factors in determining stress levels in staff and suggest several possible intervention strategies. One intervention point may be to teach self‐management techniques to help some staff cope with periods of high demand, particularly those reporting high levels of neuroticism.
Study of the mechanism of Flavobacterium sp. for hydrolyzing organophosphate pesticides
Authors: Ortiz‐Hernández M.L. , Quintero‐Ramírez R. , Nava‐Ocampo A.A. , Bello‐Ramírez A.M.
Published: November 2003

The biotransformation by Flavobacterium sp. of the following organophosphate pesticides was experimentally and theoretically studied: phorate, tetrachlorvinphos, methyl‐parathion, terbufos, trichloronate, ethoprophos, phosphamidon, fenitrothion, dimethoate and DEF. The Flavobacterium sp. ATCC 27551 strain bearing the organophosphate‐degradation gene was used. Bacteria were incubated in the presence of each pesticide for a duration of 7 days. Parent pesticides were identified and quantified by means of a gas‐chromatography mass spectrum system. Activity was considered as the amount (μmol) of each pesticide degraded by Flavobacterium sp. Also, structural parameters obtained by means of the CAChe program package for biomolecules, the reactivity index of phosphorus, of oxygen at the P=O function and of sulfur at the P=S function, and lipophilicity (log Poct) (ALOGPS v. 2.0) were obtained for each pesticide. Pesticides were hydrolyzed at the bond between phosphorous and the heteroatom, producing phosphoric acid and three metabolites. Enzymatic activity was significantly explained by the following multiple linear relationship:
image

Finally, a mechanism of Flavobacterium sp. to hydrolyze pesticides was proposed.
Justo González, Acts: The Gospel of the Spirit
Authors: Rollins Wayne G.
Published: November 2003

Book reviewed in this article:

Justo González, Acts: The Gospel of the Spirit
Don Cupitt, Is Nothing Sacred? The Non‐Realistic Philosophy of Religion
Authors: Compson Jane
Published: November 2003

Book reviewed in this article:

Don Cupitt, Is Nothing Sacred? The Non‐Realistic Philosophy of Religion
Evolution of spatial expression pattern
Authors: Johnson Louise J. , Brookfield John F. Y.
Published: November 2003

Summary How can complex patterns of gene expression evolve? Understanding the near‐precise repeatability of morphology created by animal development, through the interactions between morphogens and networks of transcription factors, is one of the most difficult outstanding problems in developmental biology. Spatial patterns are created in part by interactions between transcription factors and their DNA targets. Here we simulate the evolution of such interactions to compare the success and the evolvability of simple and complex gene networks in reaching a desired spatial pattern of expression along an embryo. We find that adding more genes to a network makes only a slight difference to evolvability. Expression patterns can evolve within a few hundred mutational events, and some simulations show partial redundancy. However, there is wide variation between simulations, with both simple and complex networks being liable to reach evolutionary “dead ends” that can only be escaped by means of an advantageous combination of individually deleterious mutations.
Antidiabetic Drug Therapy of African‐American and White Community‐Dwelling Elderly Over a 10‐Year Period
Authors: Lindblad Catherine I. , Hanlon Joseph T. , Artz Margaret B. , Fillenbaum Gerda G. , Mccarthy Teresa C.
Published: November 2003

Objectives: To determine the prevalence and predictors of antidiabetic medication use over a 10‐year period in a general population of African‐American and white community‐dwelling elderly.

Design: Survey.

Setting: Five adjacent counties (one urban and four rural) in the Piedmont area of North Carolina.

Participants: Those aged 65 and older present at the baseline (n=4,136), second (n=3,234), third (n=2,508), and fourth (n=1,633) in‐person waves of the Duke Established Populations for Epidemiologic Studies of the Elderly.

Measurements: The use of six discrete categories of antidiabetic medications (insulin, first‐generation oral sulfonylureas, second‐generation oral sulfonylureas, metformin, oral combination therapy, and insulin combination therapy) was determined. Multivariate analyses, using weighted data adjusted for sampling design, were conducted to assess the association between antidiabetic medication use and race and other sociodemographic, health‐status, and access‐to‐healthcare factors at baseline and 10 years later.

Results: Antidiabetic medications were taken by 21.4% of the population at baseline; this increased to 28.1% at the 10‐year follow‐up (P<.001). Insulin was the most commonly used drug at baseline (7.9%). The use of second‐generation sulfonylureas increased, and use of first‐generation sulfonylureas decreased over the 10‐year time period. Combination antidiabetic therapy and metformin use was infrequent throughout the study. Multivariate analyses revealed that, at baseline, African Americans were nearly twice as likely (adjusted odds ratio (AOR)=1.93, 95% confidence interval (CI)=1.46–2.54) to receive any antidiabetic medication as their white counterparts. Other significant (P<.05) factors were hypertension (AOR=1.38, 95% CI=1.03–1.84), stroke (AOR=1.98, 95% CI=1.43–2.73), one or more mobility difficulties (AOR=1.29, 95% CI=1.01–1.66), continuity of care (AOR=1.74, 95% CI=1.20–2.54), and multiple doctor visits (1–4 visits, AOR=1.69, 95% CI=1.08–2.65; ≥5 visits, AOR=3.15, 95% CI=1.95–5.07). Being underweight (AOR=0.45, 95% CI=0.30–0.67) and being cognitively impaired (AOR=0.60, 95% CI=0.41–0.87) were factors significantly (P<.05) associated with a decreased risk of antidiabetic medication use. At the 10‐year follow‐up, similar trends were seen associating these sociodemographic, health‐status, and access‐to‐healthcare factors with antidiabetic medication use.

Conclusion: Antidiabetic medication use is common and increases over time for community‐dwelling elderly. Race is significantly associated with antidiabetic medication use, even after controlling for other sociodemographic, health‐status, and access‐to‐healthcare variables.
Selected As the Best Paper in the 1990s: Reducing Frailty and Falls in Older Persons: An Investigation of Tai Chi and Computerized Balance Training
Authors: Wolf Steven L. , Barnhart Huimnan X. , Kutner Nancy G. , Mcneely Elizabeth , Coogler Carol , Xu Tingsen ,   and the Atlanta FICSIT Group
Published: November 2003

Objectives: To evaluate the effects of two exercise approaches, tai chi (TC) and computerized balance training (BT), on specified primary outcomes (biomedical, functional, and psychosocial indicators of frailty) and secondary outcomes (occurrences of fall).

Design: The Atlanta Frailty and Injuries: Cooperative Studies and Intervention Techniques, a prospective, randomized, controlled clinical trial with three arms (TC, BT, and education (ED)). Intervention length was 15 weeks, with primary outcomes measured before and after intervention and at 4‐month follow‐up. Falls were monitored continuously throughout the study.

Setting: Persons aged 70 and older living in the community.

Participants: A total of 200 participants, 162 women and 38 men; mean age was 76.2.

Measurements: Biomedical (strength, flexibility, cardiovascular endurance, body composition), functional instrumental activities of daily living (IADL), and psychosocial well‐being (Center for Epidemiological Studies for Depression scale, fear of falling questionnaire, self‐perception of present and future health, mastery index, perceived quality of sleep, and intrusiveness) variables.

Results: Grip strength declined in all groups, and lower extremity range of motion showed limited but statistically significant changes. Lowered blood pressure before and after a 12‐minute walk was seen following TC participation. Fear of falling responses and intrusiveness responses were reduced after the TC intervention compared with the ED group (P=.046 and P=.058, respectively). After adjusting for fall risk factors, TC was found to reduce the risk of multiple falls by 47.5%.

Conclusion: A moderate TC intervention can impact favorably on defined biomedical and psychosocial indices of frailty. This intervention can also have favorable effects upon the occurrence of falls. TC warrants further study as an exercise treatment to improve the health of older people.
The Boundaries and Limitations of Agency Theory and Stewardship Theory in the Venture Capitalist/Entrepreneur Relationship
Authors: Arthurs Jonathan D. , Busenitz Lowell W.
Published: November 2003

The dynamic ownership arrangements surrounding the venture capitalist–entrepreneur (VC–E) relationship inherent in new ventures make the examination of principals’ or venture capitalists’ (VCs) and agents’ (entrepreneurs) governance arrangements interesting to explore. This article examines the limitations of agency theory and then stewardship theory in explaining the behaviors of individuals in the VC–E relationship. Our analysis points out the potential problems inherent in each theory's explanatory ability as it relates to the VC–E relationship. Lastly, theoretical gaps in the VC–E relationship are discussed along with suggestions for new theory surrounding this important and intriguing relationship.
The Need for Comprehensive Evaluation in Science Education
Authors: KUMAR DAVID D. , ALTSCHULD JAMES W.
Published: November 2003

This article argues for policies regarding the implementation of evaluation as an integral part of science education reform. Approaches to evaluation should be made comprehensive enough to include multiple methods and, through their use, to gain in‐depth information on large‐scale science education programs and projects. There must be a sustained commitment from stakeholders such as the National Science Foundation to support the training of specialists in the evaluation of science education. Specialists who are able to arrive at independent conclusions that are meaningful and beneficial for science teaching and learning are needed. Evaluation recommendations posited by the authors should be put through careful analysis and feasibility testing before moving to widespread adoption.
Surface changes of ram spermatozoa by adsorption of homologous and heterologous seminal plasma proteins revealed by partition in an aqueous two-phase system
Authors: Ollero M. , García-López N. , Pérez-Pé R. , Cebrián-Pérez J. A. , Muiño-Blanco T.
Published: November 2003

Ram spermatozoa freed from seminal plasma by a dextran ‘swim-up’
procedure were incubated with Tween 20 and fractionated into motile (PEG-rich)
and stationary (dextran-rich) fractions by centrifugal countercurrent
distribution (CCCD) in an aqueous dextran–Ficoll– polyethylene
glycol (PEG) two-phase system. Increasing concentrations of Tween 20 resulted
in greater amounts of extracted protein and lower cell viability. Addition of
bull seminal plasma increased the proportion of live cells, whereas ram
seminal plasma increased the proportion of stationary cells. Proteins isolated
from each type of seminal plasma restored the CCCD profile of treated
spermatozoa to the right, this effect being reduced when proteins were
thermally denatured. Bovine serum albumin induced a slight displacement to the
left. No restoration of profile was achieved when ram spermatozoa were exposed
to proteins from bull seminal plasma in the presence of protein-free ram
seminal plasma. Adsorption of seminal plasma proteins by spermatozoa
previously stripped of surface proteins by exposure to detergent reversed the
detergent effect on motility. The findings are consistent with the concept
that ram seminal plasma contains a factor that interferes with protein
adsorption on the cell surface and prevents the protective effect of seminal
plasma proteins on maintenance of cell viability
Seasonal effects on ovarian responsiveness to exogenous gonadotrophins and successful artificial insemination in the snow leopard (Uncia uncia)
Authors: Roth Terri L. , Armstrong Doug L. , Barrie Michael T. , Wildt David E.
Published: November 2003

Ovaries of the seasonally-breeding snow leopard
(Uncia uncia) were examined to determine whether they
were responsive to exogenous gonadotrophins throughout the year. The potential
of laparoscopic artificial insemination (AI) also was assessed for producing
offspring. During the non-breeding, pre-breeding, breeding and post-breeding
seasons, females (n = 20) were treated with a
standardized, dual-hormone regimen given intramuscularly (600 I.U. of equine
chorionic gonadotrophin followed 80–84 h later with 300 I.U. of human
chorionic gonadotrophin (hCG)). Laparoscopy was performed 45–50 h after
administration of hCG, and all ovarian structures were described. Females with
fresh corpora lutea (CL) were inseminated, and anovulatory females were
subjected to follicular aspiration to examine oocyte quality. Snow leopards
responded to exogenous gonadotrophins throughout the year. Mean number of
total ovarian structures (distinct follicles mature in appearance plus CL) did
not differ (P ≥ 0 · 05) with season, but the proportion of CL :
total ovarian structures was greater (P < 0 ·
01) for the breeding season compared with all other seasons. The proportion of
females ovulating was greater (P<0 · 05)
during the breeding and post-breeding seasons than during the pre-breeding and
non-breeding seasons respectively. No Grade-1 quality oocytes were recovered
from follicles of anovulatory females. Serum concentrations of oestradiol-17b
appeared elevated in all females, and neither oestradiol-17β
concentrations nor progesterone concentrations differed
(P ≥ 0 · 05) among seasons. Of 15 females
artificially inseminated, the only one that was inseminated in the
non-breeding season became pregnant and delivered a single cub. This is the
first successful pregnancy resulting from AI in this endangered species.
Zoonoses and fertility control in wildlife—requirements for vaccines
Authors: Stöhr K. , Meslin F.-X.
Published: November 2003

This paper reflects on public health considerations on the voluntary release
of anti-fertility vaccines for wildlife in the environment. The World Health
Organization (WHO) has established a variety of recommendations on safety and
efficacy requirements for the voluntary release of rabies vaccines used for
oral immunization of animals.
These requirements cover aspects of control of rabies and possible biological
consequences in the target population. They also deal with the protection of
the health of humans and other non-target species that might come into contact
with the different oral rabies vaccines used in various parts of the world.
These recommendations are laid down in several WHO publications. They are
specific to the disease concerned, the target animal reservoir, the
relationship and types of contact between humans and target animals, the
vaccines and baits used and the respective conditions of oral immunization of
wildlife in densely-populated areas. Many of these recommendations also apply
to the development and application of contraceptive vaccines for wildlife
carnivores. Additional safety requirements concern the transmissibility of the
antigen, the reversibility of the intervention within an individual animal and
in animal populations, as well as the species specificity of the antigen used.
The management of animal populations that are reservoirs for zoonotic diseases
is a possible means by which diseases that are transmissible from animals to
humans could be prevented. Oral contraception by means of vaccines is an
appealing method, provided that requirements for protecting public and animal
health, as well as ensuring environmental safety, are precisely defined and
strictly adhered to.
Cytokine enhancement of immune responses important for immunocontraception
Authors: Ramsay Alistair J. , Ramshaw Ian A.
Published: November 2003

To be effective, an immunocontraceptive vaccine should elicit strong,
sustained antibody responses. Circulating antibodies may block the function of
hormones and target some gamete antigens, but the most effective inhibition of
fertilization will probably be achieved by antibodies in the reproductive
tract. It may also be beneficial to administer vaccine antigens with strong
adjuvants, such as cytokines, in order to achieve high specific antibody
titres. In this review, recent findings concerning the role of cytokines in
the regulation of antibody responses, particularly at mucosae, are described
and prospects for immunization for immune responses which may be important for
fertility control are discussed. On the basis of these findings, a model
system for the delivery of vaccine antigens to the immune system in vaccinia,
fowlpox or DNA plasmid vectors along with type-2 cytokines, such as
interleukin-4 (IL-4), IL-5 and IL-6, as B cell adjuvants is presented. Studies
such as these in the areas of antigen delivery and enhancement of immune
responses are aimed at providing new options for fertility control,
particularly via oral vaccination.
A bait-delivered immunocontraceptive vaccine for the European red fox (Vulpes vulpes) by the year 2002?
Authors: Bradley Mark P. , Hinds Lyn A. , Bird Peter H.
Published: November 2003

An orally-delivered immunocontraceptive vaccine is being developed for the
control of fox populations. A number of genes (PH-20,
LDH-C4, ZP3) encoding gamete proteins have been cloned,
produced in recombinant expression systems and used in fertility trials to
test the efficacy of these antigens. As the immunocontraceptive vaccine will
be delivered in a bait, there is a requirement for a greater understanding of
the immune responses of the reproductive mucosa in canids, and the assessment
of the best vaccine delivery system that will evoke a mucosal antibody
response. Several vaccine delivery systems including microencapsulated
antigens, and both vaccinia virus and bacterial vectors are being
investigated. Oral administration of
Salmonella typhimurium recombinants expressing different
fox sperm antigens stimulates both systemic IgG responses to the antigen and a
mucosal immune response within the female reproductive tract in the fox,
indicating that salmonella may have potential with respect to the oral
delivery of antigen. The enhancement of mucosal immune responses to
orally-delivered vaccines is also being examined, research focussing on the
possible use of fox-specific cytokines or the β-subunit of cholera toxin
in forming part of the vaccine construct.
Selection of antigens for use in a virus-vectored immunocontraceptive vaccine: PH-20 as a case study
Authors: Holland Michael K. , Andrews Jason , Clarke Hannah , Walton Clayton , Hinds Lyn A.
Published: November 2003

The European wild rabbit (Oryctolagus cuniculus) has
become the major agricultural and environmental pest species in Australia.
Current methods of rabbit control are lethal procedures which are increasingly
questioned for their overall efficiency, applicability, specificity, cost and
humaneness. New initiatives are required. One such initiative is
virus-vectored immunocontraception. In this approach, the lagomorph-specific
myxoma virus will be genetically engineered to include genes encoding
components of rabbit gametes which can induce an immune response that causes
infertility. Central to such a strategy is the ability to identify antigens
capable of inducing an immunocontraceptive response. A strategy for
identifying such antigens has been described previously. A case study of one
sperm antigen, PH-20, is reported here. The issues involved in developing this
antigen to the stage where it could be considered as a candidate for insertion
into a recombinant myxoma virus with the ultimate goal of testing for
immunocontraceptive efficacy are discussed. Techniques for inserting genes
into myxoma virus have been described previously. The knowledge gained from
research with this particular antigen are broadly applicable to other antigens
used for both immunocontraceptive vaccines in general and, specifically, for
virus-vectored immunocontraception.
Isolation and partial characterization of tammar wallaby luteinizing hormone and development of a radioimmunoassay
Authors: McFarlane James R. , Rudd Carl D. , Foulds Lynda M. , Fletcher Terry P. , Renfree Marilyn B.
Published: November 2003

Tammar wallaby (Macropus eugenii) luteinizing hormone
(LH) was purified from pituitaries collected from wild and captive populations
by salt sequential precipitation, ion exchange chromatography and gel
filtration. Pituitary tissue (5 g) yielded 1·8 mg of purified wallaby
luteinizing hormone (ME-14B), as verified by sodium dodecyl sulfate
polyacrylamide gel electrophoresis (SDS-PAGE). A heterologous radioimmunoassay
has been developed for measurement of LH in plasma of marsupials using a
monoclonal antibody raised against bovine LH (518B7). This assay system was
able to measure basal LH concentrations in male and female tammars and
detected a significant rise in plasma LH in response to oestradiol benzoate in
female tammars and luteinizing hormone-releasing hormone (LHRH) in males.
Parallel dose–response curves were also obtained from pituitary extracts
from four other species of marsupial (brushtail possum,
Trichosurus vulpecula; brown
antechinus,Antechinus stuartii; kowari,
Dasyuroides byrnei; and Eastern pygmy
possum,Cercartetus nanus) in this assay, which suggests
its usefulness in the measurement of LH in other marsupial species.
Male-dependent variability of fertilization and embryo development in two bovine in vitro fertilization systems and the effects of casein phosphopeptides (CPPs)
Authors: Kreysing U. , Nagai T. , Niemann H.
Published: November 2003

This study investigated the effects of semen from five different bulls and two
different ejaculates of the same bull on penetration, cleavage, blastocyst
formation, and cell allocation in bovine blastocysts produced
in vitro. Casein phosphopeptides (CPPs) were tested for
their ability to enhance fertilization and minimize variability among bulls
and ejaculates. In Experiment 1, the BO-fertilization system was employed.
Penetration and polyspermy both displayed great variation among bulls and
between ejaculates, whereas no significant differences were observed in
cleavage and blastocyst-formation rates. Similar variability was observed in
penetration, polyspermy, cleavage, blastocyst-formation rates and cell
allocation and distribution when the two fertilization systems, TALP and BO,
were compared in Experiment 2. The BO-system supported penetration and
polyspermy better (P < 0·05) than the
TALP-system, whereas the TALP-system was superior (P
< 0·05) in supporting cleavage and blastocyst formation. Significant
interactions existed between bulls and the fertilization system employed.
It is concluded that the success of
in vitrofertilization is markedly dependent on
individual bulls as well as on ejaculates from the same bull. CPPs are able to
enhance penetration and embryo development in certain bulls or ejaculates and
thus contribute to reducing the degree of individual variability, but they do
not generally improve the success of bovine embryo production
in vitro.
Collagen in the fetal membranes of sheep: changes throughout gestation and effects of dexamethasone at 60 days
Authors: Shandley Lynne , Moritz Karen M. , Samuel Chrishan S. , Wintour E. Marelyn
Published: November 2003

The tensile strength of fetal membranes is largely due to their collagen
content. In this study we have examined the changes in collagen in the
amniotic and allantoic membranes of the sheep over a wide gestational range
(27–142 days of gestation; term, 145–150 days). The results have
been correlated with volume changes in normal development, and in particular,
the changes in allantois have been studied after a rapid and extensive
increase in allantoic volume, as a result of maternal dexamethasone treatment
(0·76 mg h-1 for 48 h) from Day 60 of gestation.
Electron microscopy and immunohistochemistry were used to delineate collagen
distribution, and gel electrophoresis was used to assess the relative
proportions of each type. In the amnion, collagen content increased from
37±4% to 50±1% dry weight of the tissue from
41–102 days and declined slightly thereafter. In the allantois, collagen
content increased from 20±1% at Day 27 to 50±6% at
Day 142, significantly correlated with a volume increase from 253 mL to
813±274 mL. Collagen types I (>85%), III (10%) and
small amounts of types IV and V (<5%) were identified in both
membranes at all ages. When allantoic fluid volume was increased rapidly by
maternal dexamethasone infusion, there was a significant decrease in collagen
content from 38±6% to 25±2%
(P < 0·05). By immunohistochemistry it was
observed that both epithelial cells and fibroblasts were synthesizing
collagen.
Characterization and proteolytic activity of a cathepsin L-like polypeptide in endometrium and uterine flushings of cycling, pregnant and steroid-treated ovariectomized gilts
Authors: Geisert Rodney D. , Blair Robert M. , Pratt Thea , Zavy Michael T.
Published: November 2003

Cathepsin L has been proposed to be involved with the
endothelial–chorial type of placentation in the cat. Little information
concerning the presence and secretion of cathepsin L is available for a
species with noninvasive epitheliochorial placentation such as the pig.
Cathepsin L activity in uterine flushings and endometrium from gilts during
different days of the oestrous cycle and early pregnancy was analysed through
specific substrate metabolism and Western blot analyses with antiserum against
cat endometrial cathepsin L. This antiserum was utilized to determine the
cellular localization of the enzyme within porcine endometrium. Cathepsin L
activity within uterine flushings was elevated on Day 15 of the oestrous cycle
and early pregnancy, with activity declining on Day 18. Cat cathepsin L
antiserum cross-reacted with a group of 46, 40 and 38 kDa uterine proteins and
detected a product within the surface and glandular epithelium of the
endometrium. The appearance of the 40 kDa protein was first detected on Day 10
of the oestrous cycle with the 38 kDa proteins appearing on Day 15 and 18 of
pregnancy. The 40 and 38 kDa uterine proteins appear to be steroid regulated
as 12 days of progesterone administration is necessary to detect the proteins
and cathepsin L activity.
Role of glucose, fatty acids and protein in regulation of testicular growth and secretion of gonadotrophin, prolactin, somatotrophin and insulin in the mature ram
Authors: Boukhliq Rachid , Martin Graeme B. , White Colin L. , Blackberry Margaret A. , Murray Peter J.
Published: November 2003

This study tested whether the effects of nutrition on gonadotrophin secretion
and testicular growth in mature rams are due to increases in the supply of
glucose, fatty acids (FA) or amino acids. Responses to protein (casein) and
glucose, alone or in combination, were compared with responses to lupin grain
and responses to a combination of protein, glucose and FA (acetate, propionate
and vegetable oil). Glucose and casein were infused intra-abomasally whereas
lupins and FA were added to the diet. Lupin feeding decreased blood growth
hormone (GH) concentrations, but increased pulsatile luteinizing hormone (LH)
secretion and increased the concentrations of follicle-stimulating hormone
(FSH), prolactin, glucose and insulin. These effects were associated with
testicular growth. Glucose or casein increased insulin concentrations and
decreased GH concentrations, but did not affect gonadotrophins or testicular
growth. There was no synergism between casein and glucose. Responses elicited
by adding FA to the glucose+casein treatment were similar to those
observed with lupins. In conclusion, the reproductive axis does not seem to be
closely linked with dietary intakes of amino acids or with circulating
concentrations of glucose, insulin or GH. However, the energetic components of
the diet, particularly the fatty acids, appear to play a key role in the
reproductive responses to changes in nutrition.
In vivo effects of epidermal growth factor on epidermal pattern formation and hair follicle initiation in the marsupial bandicoot Isoodon macrourus
Authors: Adelson David L. , Hollis David E. , Merchant James C. , Kelley Bronwyn A.
Published: November 2003

The extrauterine development of marsupial pouch young (northern brown
bandicoot Isoodon macrourus) has facilitated the study
of the effects of murine epidermal growth factor (mEGF) on pattern formation
in skin. Hair follicle initiation and development, which in the mouse would
occur from about Days 13–14 of gestation onward, occurs postnatally. In
the present study the effect in vivo of mEGF on
developing skin corresponding to mouse gestational ages from Day 13 onward was
examined. Subcutaneous injections of mEGF (0· 5, 1 ·0 and
2· 0 µg g-1 body weight) or equivalent
volumes of saline (0· 9% w/w) were administered daily,
before and during hair follicle initiation and development. Murine EGF
inhibited the formation of hair follicles, hair follicle sweat glands,
sebaceous glands and dermal papillae. The pattern of follicle initiation was
perturbed. The characteristic trio follicle grouping was absent, and follicle
rudiment densities (no. per mm2skin surface) were
significantly lower in animals treated with mEGF, whereas follicle diameters
were increased. These data may reflect a role for the epidermal growth factor
(EGF) receptor in epidermal pattern formation. The EGF receptor and its
potential ligands (such as EGF, transforming growth factor (TGF-α) or
other yet-to-be-discovered ligands) perhaps act as parts of a pattern-forming
system in vertebrate skin.
Extra keyword: EGF receptor.
Parthenogenetic activation of pig eggs by exposure to protein kinase inhibitors
Authors: Prather R. S. , Mayes M. A. , Murphy C. N.
Published: November 2003

The objective of the present study was to assess the effect of low
concentrations of protein kinase inhibitors on activation. Pig eggs were
electrostimulated or cultured with the following: 10 µM
1-[5-isoquinolinylsulfonyl]-2-methylpiperazine, HCl H7 for 24 h; 100
µM H7 for 24 h; 10 nM staurosporine for 24 h; or with 20 µM
staurosporine for 20 min followed by Whitten’s medium for 24 h. Rates of
pronuclear formation in eggs (n = 1240) subjected
to these treatments were: untreated, 6·2%; electrostimulated,
77·1%; 10 M H7, 10·0%; 100 µM H7,
65%; 10 nM staurosporine, 24·2%; and 20 µM
staurosporine, 67·3% (significance at P
£ 0· 05: 10 µM H7 vs untreated, not significant; 20
µM staurosporine vs 100 µM H7, not
significant). Percentages of eggs (n = 125)
expressing a 22-kDa band after treatment were: untreated, 37·5%;
electrostimulated, 100%; 10 µM H7, 72%; 100 µM H7,
66·7%; 10 nM staurosporine, 40 ·0%; and 20
µM staurosporine, 77· 3% (significance at
P ≤ 0·10: 100 µM H7, 10 nM staurosporine
and 20µM staurosporine vs 10 µM H7, not significant; 100 µM
H7 and 10 nM staurosporine vs untreated, not significant). Transmission
electron microscopy of ultrathin sections of treated eggs revealed that
cortical granules were present in over half the untreated eggs, as well as
over half of the eggs treated with 100 µM H7 or 10 nM staurosporine; in
contrast, all cortical granules were absent from electrically-activated eggs.
The results indicate that long-term exposure of eggs to low concentrations of
broad-spectrum protein kinase inhibitors induces some of the events commonly
associated with fertilization.
Effect of desialylation of highly purified isoforms of human luteinizing hormone on their bioactivity in vitro, radioreceptor activity and immunoactivity
Authors: Burgon Patrick G. , Stanton Peter G. , Pettersson Kim , Robertson David M.
Published: November 2003

To establish whether sialic acid content is responsible for an observed
7–8-fold variability in bioactivity in vitro of
highly purified human pituitary luteinizing hormone (hLH) isoforms, the
bioactivity in vitro, radioreceptor activity and
immunoactivity of hLH isoforms were determined before and after enzymatic
desialylation. Three immunofluorometric assays with different hLH
specificities allowed characterization of 13–24 pituitary hLH isoform
preparations of pI 7·03–8·98 in terms of sialic acid
content (1–5 sialic acid residues per LH molecule), bioactivity
in vitro (4030–30 000 I.U.
mg-1), radioreceptor activity (6420–25 400 I.U.
mg-1) and hLH immunoactivity (2900–4400 to 18
300–27 300 I.U. mg-1). Significant positive
correlations between sialic acid content and either immunoactivity or in vitro
bioactivity were observed, whereas radioreceptor activity showed a curvilinear
response. Following more than 90% removal of sialic acid, both
in vitro bioactivity and radioreceptor activity were
increased, although specific activity still differed between isoforms;
immunoactivities were unaffected. It is concluded that the presence of the
sialic acid residue(s) on hLH isoforms does partially contribute to the
in vitro bioactivity and radioreceptor activity of the
isoforms, but that hLH immunoactivity is independent of sialic acid content.
Localization and synthesis of collagen types III and V during remodelling and decidualization in rat uterus
Authors: Hurst Peter R. , Palmay Rochelle D. , Myers Don B.
Published: November 2003

Uteri of pregnant rats on Days 6, 7 and 8 of pregnancy were studied to
determine the histochemical distribution of collagen types III and V and the
incorporation of [3H]glycine into fibrillar
collagens during the period of embryonic implantation. Types III and V had a
similar distribution in the non-decidual stromal region and muscle layers in
implantation sites. They were found to have very low levels in the primary
decidual tissue on Day 6 and were not detected in developing decidual tissues
on Days 7 or 8. Following injection of labelled glycine, collagen was
extracted and the specific activity of the collagens determined by
fluorography and 3H incorporated into the collagen bands
in the gels. It was found that incorporation of label into both types I and
III was similar (33· 4 ± 12·0 and 31·
8±18·1 cpm µg-1 collagen
respectively) but 3·5 times that of type V (7·7 ±
5·3 cpm µg-1 ). These studies suggest that
although fibrillar collagens are metabolized or redistributed in the growing
decidual tissue, they are incorporated rapidly into the extracellular matrix
during remodelling of the outer stroma and muscle tissues.
Prostaglandin and progesterone production by bovine luteal cells incubated in the presence or absence of the accessory cells of the corpus luteum and treated with interleukin-1β, indomethacin and luteinizing hormone
Authors: Vecchio R. P. Del , Sutherland W. D.
Published: November 2003

This experiment examined production of prostaglandin (PG)
F2α , PGE2 and progesterone
by bovine luteal cells incubated with or without the accessory cells and
treated with recombinant bovine interleukin-1β (10 ng), indomethacin (5
µg) or luteinizing hormone (50 ng). During pretreatment, progesterone
production was similar in the luteal and luteal plus accessory cells, being
greater in either of these than in accessory cells;
PGF2α was greatest in luteal plus accessory,
intermediate in accessory and lowest in the luteal cells; PGE2 was similar
among all cell arrangements. Luteinizing hormone or luteinizing hormone plus
indomethacin stimulated progesterone in the luteal and luteal plus accessory
cells, this being similar in these two cell arrangements. Interleukin-1β
stimulated PGF2α in luteal and luteal plus
accessory cells, and tended to elevate PGF2α in
accessory cells. Interleukin-1β stimulated PGE2 in
all cell arrangements. Indomethacin inhibited the interleukin-1b-stimulated
PGF2α and PGE2 release.
Indomethacin or indomethacin plus luteinizing hormone inhibited basal
PGE2 in luteal and luteal plus accessory cells. These
data suggest that progesterone production is not inßuenced by the
presence of accessory cells of the corpus luteum, that accessory and luteal
cells produce appreciable amounts of PG, and that recombinant bovine
interleukin-1b stimulates PGE2 and
PGF2α in the luteal and accessory cells.
Seasonal patterns of luteal cyclicity in young red deer (Cervus elaphus) and sambar deer (Cervus unicolor)
Authors: Asher G. W. , Muir P. D. , Semiadi G. , O'Neill K. T. , Scott I. C. , Barry T. N.
Published: November 2003

Seasonal onset of pubertal ovulation and incidence of luteal cyclicity was
assessed from plasma progesterone proles over 15 months for tame red deer
(n = 7) and sambar deer (n
= 7) hinds. Seasonal responses to photoperiod were determined from
plasma prolactin proles. All red deer attained puberty at 17-18 months of age
in May-June and expressed 3-6 luteal cycles of length 20·0 ±
10·4 days (mean ± s.e.m.) over 52-102 days. Six sambar deer
attained puberty at 7-19 months of age, between August and December. Duration
of luteal cyclicity was variable. While one animal remained continuously
cyclic for 13 months, most entered anoestrus between November and February.
The mean length of the luteal cycle was 17·2 ± 0·3 days.
While red deer exhibited strongly seasonal patterns of prolactin secretion,
sambar deer showed no such seasonal trends. The data collectively indicate
that young sambar hinds at temperate latitudes exhibit loosely dened patterns
of reproductive seasonality that are 4-6 months out of phase with those of red
deer, although some individuals may be non-seasonal. Failure to express
seasonal patterns of prolactin secretion indicates that sambar deer may not
perceive photoperiodic cues to the same extent as do red deer.
Ontogeny of thyroid hormone receptors in the brushtail possum (Trichosurus vulpecula)
Authors: Sernia Conrad , Zeng Tang , Gemmell Robert T.
Published: November 2003

Newborn marsupials do not have a thyroid gland at birth. The gland develops
while the young marsupial is in the mother’s pouch. The young brushtail
possum initiates secretion of thyroid hormones from its own thyroid at about
Day 65 post partum. However, during the first three
weeks of pouch life thyroxine is passed from the mother to the young via the
milk. To determine if this maternal thyroxine can effect organ development in
the young possum before it initiates secretion of thyroxine from its own
thyroid, the ontogeny of thyroid hormone receptors was determined in nuclear
extracts of lung, liver and kidney by radioreceptor assay,
using125I-labelled tri-iodothyronine as ligand. Receptor
density was calculated for tissues removed from young possums at Days 25
(n = 5), 50 (n = 4),
100 (n = 3) and 150 (n
= 4) and from adults (n = 5). Receptors
were found in possums of all age groups, including the small 25-day pouch
young. Significant differences were not found in the receptor density between
different tissues or at various ages. The association constant
Ka (4 ·0 ± 2·
6 L nmol-1 for lung) was similar in different tissues
and at the various ages examined. The passage of thyroid hormones from the
mother to the developing marsupial via the milk may have a role in the slow
development of organ systems early in pouch life by acting on thyroid
receptors in the pouch young. However, the functional maturation of the
thyroid gland of the young possum, not an increase in receptors, appears to
coincide with the rapid increase in the rate of growth and development which
occurs in later pouch life.
Effect of iron on transferrin receptor expression by human placental syncytiotrophoblast cells
Authors: Kennedy Martha L. , Douglas Gordon C. , King Barry F.
Published: November 2003

Transferrin receptor expression has been examined in primary cultures of
morphologically differentiated placental syncytiotrophoblast cells. More than
90% of the cells were multinucleated. Incubation of syncytiotrophoblast
for 4 days in the presence of iron salts had no effect on receptor expression
assessed by measuring the binding of 125I-labelled
transferrin. However, incubation of cells in the presence of human diferric
transferrin (10-100 µM) led to a 50% decrease in surface and
intracellular receptor expression. This down-regulation was not accompanied by
a signicant decrease in receptor synthesis. In contrast to
syncytiotrophoblast, expression of intracellular transferrin receptors in
non-differentiated cytotrophoblast cells decreased when cells were cultured
with iron salts; this was accompanied by decreased receptor synthesis.
Addition of diferric transferrin to cytotrophoblast cells led to a 50%
reduction in surface and intracellular receptor expression, similar to that
seen in the syncytiotrophoblast. This reduction was accompanied by a decrease
in receptor synthesis. In contrast to that of most cell types, the expression
and distribution of trophoblast transferrin receptors were not altered by
insulin, epidermal growth factor or hydrocortisone. These characteristics of
syncytiotrophoblast transferrin receptor expression may assist in ensuring a
supply of iron to the fetus regardless of the maternal iron status.
Homeobox gene HB24, a regulator of haematopoiesis, is a candidate for regulating differentiation of the extra-embryonic trophoblast cell lineage
Authors: Quinn L. M. , Latham S. E. , Kalionis B.
Published: November 2003

Expression of the human homeobox gene HB24 in the cytotrophoblast stem cell
population in rst-trimester human placenta was investigated.
HB24expression was downregulated after cytotrophoblast
had differentiated into syncytiotrophoblast. Expression of
HB24 was also detected in rst-trimester invasive
extravillous cytotrophoblast cells. In term placenta,
HB24 expression was detected in residual cytotrophoblast
cells and in syncytiotrophoblast. Northern analysis revealed two
HB24 transcripts in rst-trimester placenta of
approximately 2·5 kb and 5·3 kb. Ribonuclease protection assays
were used to conrm expression of HB24 in rst-trimester
and term placenta and also to provide evidence that HB24
is downregulated in choriocarcinoma cell lines. In addition to being required
for differentiation of the haematopoietic cell lineage,
HB24 may be required for differentiation of the
extra-embryonic trophoblast cell lineage.
Preliminary characterization of a placental factor inhibiting breathing in fetal sheep
Authors: Alvaro Ruben E. , Robertson May , Al-Saedi Saad , Lemke Robert P. , Cates Don B. , Rigatto Henrique
Published: November 2003

Previous studies have revealed a placental extract that inhibits breathing in
fetal sheep. In the present study of 29 chronically instrumented sheep at
132±1 days of gestation, infusion of the 1-10 kDa extract inhibited
breathing in 76% of the experiments whereas Krebs’ solution
inhibited it in 24%. It retained this activity after 6 months of
freezing, after lyophilization, and upon lowering the pH during purication
from 8·0 to 4·0, but it inhibited breathing in only 35%
when the pH was lowered to 2·0. A signicant dose-dependent effect was
observed from a 16-fold dilution to a 4-fold concentration. Treatment of the
extract with proteinase K or boiling reduced the activity to 30% or
26% inhibition, respectively. The activity was not adsorbed to an
ion-exchange column at pH 7·0 or 8· 0, but it was at pH
9· 0 and it eluted with increasing NaCl concentrations. On a
polyacrylamide gel the activity was eluted at a
Kav of 0· 66 (82%
inhibition), corresponding to between 2·5 and 4·5 kDa. These
ndings suggest that a peptide produced by the placenta, with a molecular mass
between 2· 5 and 4·5 kDa, inhibits fetal breathing.