Notes on age determination, size and age structure, longevity and growth of co-occurring macrourid fishes

Nineteen species of the deep-water fish family Macrouridae inhabit the Mid-Atlantic Ridge (MAR) of the North Atlantic. Size and age structure, longevity and length at age were explored for seven of the more abundant species: Coryphaenoides armatus, Coryphaenoides brevibarbis, Coryphaenoides carapinus, Coryphaenoides guentheri, Coryphaenoides mediterraneus, Coryphaenoides rupestris and Macrourus berglax. The otoliths from these species had growth increments resembling those accepted as annuli in other deep-water species for which validation experiments have been conducted. Based on the counts of these growth increments, age estimates were derived as the basis for studies of age structure, growth and longevity. All the species appeared to have relatively low growth rates, but the interspecific variation in longevity illustrates that there is a considerable variation within the family and among species inhabiting the same deep-sea environment. Most of the species likely complete full life cycles on the MAR, but it is probable that both the youngest and the largest-oldest individuals of some of the species were not sampled adequately.

Experiences of caregivers by care recipient's health condition: A study of caregivers for Alzheimer's disease and related dementias versus other chronic conditions

This study described experiences of caregivers of persons with Alzheimer's disease and other dementias (ADRD) and caregivers of persons with other chronic conditions on self-reported health, type of assistance they provide, perceptions of how caregiving interferes with their lives, and perceived level of support. A secondary analysis was conducted of the 2013 Porter Novelli SummerStyles survey data. Of the 4033 respondents, 650 adults self-identified as caregivers with 11.6% caring for people with ADRD. Over half of all caregivers reported that caregiving interfered with their lives to some extent. The greater the perceived support caregivers reported, the less they thought that caregiving interfered with their lives (p < .001). No significant differences were found between ADRD and non-ADRD caregivers regarding general health, types of assistance they provided, and perceived level of support. These findings have the potential to inform future research and practice in the development of supportive services for caregivers.

Evaluating Community-Academic Partnerships of the South Carolina Healthy Brain Research Network

Community-academic partnerships have a long history of support from public health researchers and practitioners as an effective way to advance research and solutions to issues that are of concern to communities and their citizens. Data on the development and evaluation of partnerships focused on healthy aging and cognitive health were limited. The purpose of this article is to examine how community partners view the benefits and barriers of a community-academic partner group established to support activities of the South Carolina Healthy Brain Research Network (SC-HBRN). The SC-HBRN is part of the national Healthy Brain Research Network, a thematic research network funded by the Centers for Disease Control and Prevention (CDC). It is focused on improving the scientific and research translation agenda on cognitive health and healthy aging. Semistructured interviews, conducted at end of Year 2 of the 5-year partnership, were used to collect data from partners of the SC-HBRN. Reported benefits of the partnership were information sharing and networking, reaching a broader audience, and humanizing research. When asked to describe what they perceived as barriers to the collaborative, partners described some lack of clarity regarding goals of the network and opportunities to contribute to the partnership. Study results can guide and strengthen other public health-focused partnerships.

Concern about developing Alzheimer's disease or dementia and intention to be screened: An analysis of national survey data

OBJECTIVE

Early diagnosis of Alzheimer's disease (AD) or dementia is important so that patients can express treatment preferences, subsequently allowing caregivers to make decisions consistent with their wishes. This study explored the relationship between people's concern about developing AD/dementia, likelihood to be screened/tested, if experiencing changes in cognitive status or functioning, and concerns about sharing the diagnostic information with others.

METHOD

A descriptive study was conducted using Porter Novelli's SummerStyles 2013 online survey data. Of the 6105 panelists aged 18+ who received the survey, 4033 adults responded (response rate: 66%). Chi squares were used with case-level weighting applied.

RESULTS

Almost 13% of respondents reported being very worried or worried about getting AD/dementia, with women more worried than men (p<.001), and AD/dementia caregivers more worried than other types of caregivers (p=.04). Women were also more likely than men to agree to be screened/tested if experiencing changes in memory and/or thinking (p<.001). The greater the worry, the more likely respondents would agree to be screened/tested (p<.001). Nearly 66% of respondents were concerned that sharing a diagnosis would change the way others think/feel about them, with women reporting greater concern than men (p=.003).

CONCLUSION

Findings demonstrate that level of worry about AD/dementia is associated with the reported likelihood that individuals agree to be screened/tested. This information will be useful in developing communication strategies to address public concern about AD/dementia that may increase the likelihood of screening and early detection.

Walking and Walkability: Is Wayfinding a Missing Link? Implications for Public Health Practice

BACKGROUND

Research on walking and walkability has yet to focus on wayfinding, the interactive, problem-solving process by which people use environmental information to locate themselves and navigate through various settings.

METHODS

We reviewed the literature on outdoor pedestrian-oriented wayfinding to examine its relationship to walking and walkability, 2 areas of importance to physical activity promotion.

RESULTS

Our findings document that wayfinding is cognitively demanding and can compete with other functions, including walking itself. Moreover, features of the environment can either facilitate or impede wayfinding, just as environmental features can influence walking.

CONCLUSIONS

Although there is still much to be learned about wayfinding and walking behaviors, our review helps frame the issues and lays out the importance of this area of research and practice.

Neighborhood characteristics and depressive symptoms in an older population

OBJECTIVES

We explored relationships between depressive symptoms and neighborhood environment measures including traffic safety, crime, social capital, and density of businesses in community-dwelling older adults from four different regions of the United States.

METHOD

The Healthy Aging Research Network walking study is a cross-sectional study of 884 adults aged 65+, which included a 10-item Center for Epidemiologic Studies Depression scale of depressive symptoms, demographics, self-reported neighborhood perceptions, and objective neighborhood data.

RESULTS

After adjusting for individual covariates, reports of neighborhood crime, unsafe traffic, and unwillingness of neighbors to help each other were significantly positively associated with depressive symptoms among participants.

CONCLUSION

This research suggests an association between self-reported depressive symptoms and the social and built environment; examining causal association requires additional longitudinal research in diverse populations of older adults.

Public perceptions about risk and protective factors for cognitive health and impairment: a review of the literature

BACKGROUND

Preventing and/or delaying cognitive impairment is a public health priority. To increase awareness of and participation in behaviors that may help maintain cognitive function or reduce risk of impairment, we need to understand public perceptions about risk and protective factors.

METHODS

We conducted a scoping review of studies examining the public's perceptions about risk and protective factors related to cognitive health and impairment published since the 2007 National Public Health Road Map to Maintaining Cognitive Health.

RESULTS

A search of five databases yielded 1,115 documents published between June 2007 and December 2013. Initial review of abstracts identified 90 potentially eligible studies. After full-article review, 30 met inclusion criteria; four additional articles identified in reference lists also met inclusion criteria. Of the 34, 16 studies addressed Alzheimer's disease (AD) specifically, 15 dementia broadly, 5 mild to moderate cognitive impairment, and 8 normal functioning, with some content overlap. Across studies, respondents reported genetics (n = 14 studies), older age (n = 8), stress (n = 7), brain/head injury (n = 6), and mental illness/brain disease (n = 6) as perceived risk factors for AD and dementia. Protective factors most commonly identified for maintaining cognitive health were intellectual/mental stimulation (n = 13), physical activity (n = 12), healthy diet (n = 10), and social/leisure activities (n = 10).

CONCLUSIONS

Studies identified genetics and older age as key perceived risk factors more so than behaviors such as smoking. Individuals perceived that numerous lifestyle factors (e.g. intellectual stimulation, physical activity) could protect against cognitive impairment, AD, and/or dementia. Results can inform national and international education efforts about AD and other dementias.

Developing a framework and priorities to promote mobility among older adults

Mobility, broadly defined as movement in all of its forms from ambulation to transportation, is critical to supporting optimal aging. This article describes two projects to develop a framework and a set of priority actions designed to promote mobility among community-dwelling older adults. Project 1 involved a concept-mapping process to solicit and organize action items into domains from a broad group of stakeholders to create the framework. Concept mapping uses qualitative group processes with multivariate statistical analysis to represent the ideas visually through maps. A snowball technique was used to identify stakeholders (n = 211). A 12-member steering committee developed a focus prompt, "One specific action that can lead to positive change in mobility for older adults in the United States is..." Project 2 included a Delphi technique (n = 43) with three iterations to prioritize four to six items using results from the concept mapping rating process. Project 1 resulted in 102 items across nine domains (Research to Practice, Independence and Engagement, Built Environment and Safety, Transportation, Policy, Housing and Accessibility, Community Supports, Training, and Coordinated Action). The number of items ranged from 6 to 18 per domain. Project 2 resulted in agreement on four items that reflect the importance of promoting environmental strategies through collaborative initiatives aimed at planning and best practices focusing on environmental enhancements or transit, training of professionals, and integration of mobility into state and local public health plans. These findings can be applied to support coordinated, multidisciplinary research and practice to promote mobility among older adults.

Older Adult Strategies for Community Wayfinding

Community wayfinding becomes more challenging with age and decrements in functioning. Given the growth in numbers of older adults, we need to understand features that facilitate or inhibit wayfinding in outdoor settings to enhance mobility and community engagement. This exploratory study of 35 short- ( n = 14) and long-term ( n = 21) residents in an ethnically diverse neighborhood identified relevant wayfinding factors. Data collection included an interview, map-drawing task, and walk along a previously audited, prescribed route to identify key wayfinding strategies. Most participants sought information from other people as a primary method of route planning. Street signs and landmarks were overwhelming favorites as helpful wayfinding features. When asked to recall the route following the walk, only half of participants gave completely correct directions. Findings reinforce the importance of landmarks and legible, systematic, and consistently available signage, as well as trustworthy person-to-person information sources. Findings also underscore the need for wayfinding research in diverse environments.

An audit of a diverse community for safe routes to age in place: environmental policy implications

Physical and cognitive limitations often accompany aging, increasing the importance of a safe and supportive environment to help older adults maintain mobility. Neighborhood design and maintenance must be evaluated to promote physical activity, mobility, and safety. Audit tools, geographic information system data, and resident interviews are used for this purpose, but often fail to provide information that can be translated to practice. The current project is part of a larger Miami-Dade Age-Friendly Initiative to create a metropolitan area that fosters a healthy environment for diverse adults of all ages and abilities. Safe Routes uses a toolkit based on the 5-E model providing practical resources to guide stakeholders in meeting the needs of the community. Findings include the Centers for Disease Control Healthy Aging Research Network Audit Tool assessment for environmental walkability factors. Results from street segment audits along with input from residents can be used to inform sound environmental policies.

Mobility Disability in Older Adults: At the Intersection of People and Places

PURPOSE

Mobility disability is associated with poor lower body function among older adults. This study examines whether specific types of neighborhood characteristics moderate that association.

DESIGN AND METHODS

This study is based on a cross-sectional sample of 884 people aged ≥ 65 years identified through service organizations in Alameda County, CA; Cook County, IL; Allegheny County, PA; and Wake and Durham counties, NC. In-person interviews focus on neighborhood characteristics, physical and cognitive function, depression, and walking. Functional capacity is tested using objective measures of lower body strength, balance, and walking speed. Mobility disability, the main study outcome, is measured as self-reported level of difficulty in walking 2-3 neighborhood blocks. Estimates of main and interactive effects are derived from logistic regression models.

RESULTS

Among older adults with poor lower body function, those who report less proximity to goods and services and barriers to walking report more mobility disability than other older adults. In contrast, among older adults with good lower body function, there is a low prevalence of mobility disability and little association between perceptions of the neighborhood and mobility disability.

IMPLICATIONS

In addition to more refined longitudinal studies, this research provides a foundation for innovative place-based rehabilitation and hospital discharge programs for older adults newly diagnosed and treated for chronic health conditions.

Environments for healthy aging: linking prevention research and public health practice

Safe and well-designed community environments support healthful behaviors that help prevent chronic conditions and unintentional injuries and enable older adults to be active and engaged in community life for as long as possible. We describe the work of the Healthy Aging Research Network (HAN) and partners over the past decade to better understand place-based determinants of health and translate that knowledge to real-world practice, with a focus on environmental strategies. Using key components of the Knowledge to Action framework, we document the importance of a sustained, multidisciplinary, collaborative approach and ongoing interaction between researchers and communities. We share examples of practical tools and strategies designed to engage and support critical sectors with the potential to enhance the health and well-being of older adults and their communities. We conclude with a description of lessons learned in facilitating the translation of prevention research into practice.

Environmental correlates of overweight and obesity in community residing older adults

OBJECTIVE

This study examines the role of environmental correlates of overweight and obesity among older adults independent of walking activity and lower body function.

METHODS

In-person interviews were conducted with 789 adults aged 65 and older, residing in four areas in the U.S. Demographic information, general health, lower body function, walking behavior, and awareness of environmental infrastructure features using the modified Neighborhood Environment Walking Survey (NEWS) were obtained. Regression analyses examined the association between Body Mass Index (BMI) and environmental infrastructure features, adjusting for demographics and lower body function.

RESULTS

Older adults who perceived their neighborhood as less safe from crime and had reduced access to services were more likely to have higher BMI. Controlling for demographic and functional characteristics, access to services remained significant. This association remained significant for those with lower functional status.

DISCUSSION

This research suggests that neighborhood environment may have an influence on BMI above and beyond walking activity.

Effects of the built environment on physical activity of adults living in rural settings

OBJECTIVE

To conduct a systematic review of the literature to examine the influence of the built environment (BE) on the physical activity (PA) of adults in rural settings.

DATA SOURCE

Key word searches of Academic Search Premier, PubMed, CINAHL, Web of Science, and Sport Discus were conducted.

STUDY INCLUSION AND EXCLUSION CRITERIA

Studies published prior to June 2008 were included if they assessed one or more elements of the BE, examined relationships between the BE and PA, and focused on rural locales. Studies only reporting descriptive statistics or assessing the reliability of measures were excluded.

DATA EXTRACTION

Objective(s), sample size, sampling technique, geographic location, and definition of rural were extracted from each study. Methods of assessment and outcomes were extracted from the quantitative literature, and overarching themes were identified from the qualitative literature.

DATA SYNTHESIS

Key characteristics and findings from the data are summarized in Tables 1 through 3.

RESULTS

Twenty studies met inclusion and exclusion criteria. Positive associations were found among pleasant aesthetics, trails, safety/crime, parks, and walkable destinations.

CONCLUSIONS

Research in this area is limited. Associations among elements of the BE and PA among adults appear to differ between rural and urban areas. Considerations for future studies include identifying parameters used to define rural, longitudinal research, and more diverse geographic sampling. Development and refinement of BE assessment tools specific to rural locations are also warranted.

Lower-body function, neighborhoods, and walking in an older population

BACKGROUND

Poor lower-body capacity is associated with reduced mobility in older populations.

PURPOSE

This study sought to determine whether neighborhood environments (e.g., land-use patterns and safety) moderate that association.

METHODS

The study is based on a cross-sectional sample of 884 people aged > or =65 years identified through service organizations in Alameda County CA, Cook County IL, Allegheny County PA, and Wake and Durham counties NC. In-person interviews focused on neighborhood characteristics, physical and cognitive function, and physical activity and walking. Functional capacity was tested using measures of lower-body strength, balance, and walking speed. The main outcome was time spent walking in a typical week (<150 vs > or =150 minutes per week). Objective environmental measures were also included. Estimates of main and interaction effects were derived from regression models.

RESULTS

Living in a residential area, compared to a mixed-use or commercial area, was associated with less time spent walking (<150 minutes per week; OR=1.57, 95% CI=1.04, 2.38). Living in a less-compact area (greater median block length) is also significantly associated with less walking for seniors, but only among those with excellent lower-body strength.

CONCLUSIONS

Neighborhood type is associated with walking among older people, as it is among the general adult population. In individuals with poor lower-body function, no association was found between residence in a less-compact area and walking. For those people, the relationship between neighborhood characteristics and walking requires further study.

Treatment, management, and control: improving outcomes through more treatment and less control

Outcomes in psychiatric care are improved by expanding treatment options and reducing dependence on management and control interventions.

Histophysiology of the Fallopian tubes in relation to sperm binding, release, and completion of capacitation

This paper is concerned with endosalpingeal specialisations that underlie stabilisation of unique secretions forming microenvironments within the Fallopian tube lumen, not least as they influence the final stages of sperm transport and maturation. In particular, a specific microenvironment at the ampullary-isthmic junction in the presence of the newly-shed oocyte(s), associated granulosa cells and their secretory products is thought to characterise the site of fertilisation. Attention is also drawn to the viscous glycoprotein in the caudal isthmus before ovulation: it isolates spermatozoa stored with suppressed motility from the metabolic stimulation caused by uterine or ampullary fluid. This viscous secretion strips male antigens from the sperm surface, facilitating their preovulatory binding reactions to organelles of the isthmus epithelium. Peri-ovulatory activation of discrete numbers of viable spermatozoa is regulated by follicular progesterone secretion, but seemingly involves local mobilisation of Ca2+ ions into bound gametes of appropriate membranous maturity. Motility and progression to the site of fertilisation may be further heightened by an influence of catecholamines diffusing from the myosalpinx; receptors for such molecules are present on the sperm surface. There is tight control of sperm activation and release close to the time of ovulation, generating initial sperm:egg ratios at the ampullar-isthmic junction of close to unity. However, with establishment of the block to polyspermy in newly activated eggs and lapse of time after ovulation, control of sperm progression soon relaxes. Indeed, 2-4 cell embryos may contain large numbers of accessory spermatozoa on or in the zona pellucida.

Physiological and pharmacological aspects of local transfer of substances in the ovarian adnexa in women

An intimate arrangement between the utero-ovarian vein and the ovarian artery has been found in many species. The anatomical structure suggests the existence of a counter-current system of exchange, and many animal experiments point to a physiological importance of this transfer system. In man, the utero-ovarian vein forms a plexus around the ovarian artery. In-vitro experiments have demonstrated a local transfer of progesterone; in-vivo experiments have proved that krypton and progesterone can be transferred from the utero-ovarian vein to the ovarian artery. The physiological and pharmacological importance of the counter-current system is still under evaluation, and further investigations are needed. It has been suggested that counter-current transfer facilitates local communication between the ovary, Fallopian tube, and uterus. This may be important in a context of luteolysis, follicular selection and maturation, fertilization, and the recognition and maintenance of pregnancy. The pharmacological and therapeutic potential may be limited, as the ovarian adnexa are relatively difficult to access. Instillation of hormones into the uterine lumen will probably induce a higher plasma concentration in the ovarian arterial blood than in peripheral arterial plasma. A culdoscopic or endoscopic approach might permit introduction of long-acting depots in the uterine fundus near the Fallopian tubes and/or ovaries.

Pre-ovulatory graafian follicles are cooler than neighbouring stroma in pig ovaries

Using an infra-red camera, domestic pig ovaries were thermo-imaged almost instantaneously at laparotomy or within a closed abdomen by endoscopy. Rectal and jugular vein temperatures were recorded using thermo-probes. Graafian follicles (7-10 mm diameter) were cooler than ovarian stroma in all experimental models examined, and both compartments were cooler than rectal and jugular temperatures. The mean difference between follicles and stroma in 73 observations was 1.3 +/- 0.1 degrees C. When thermo-imaged under the fimbriated extremity of the Fallopian tube, follicles and stroma could still be distinguished. Follicles cooled slightly more rapidly than adjoining stroma during the first 10 s of a 60 s recording interval, after which curves for the two tissues remained parallel. Arresting ovarian blood supply for 5 min had a negligible influence on the temperature differentials. Endoscopy in three models recorded mean differentials between follicles and stroma of 0.6 +/- 0.1 degrees C to 1.1 +/- 0.1 degrees C. It is concluded that temperature gradients do exist in the ovarian tissues of mature animals, and that these are generated at least in part as a consequence of endothermic reactions within Graafian follicles.

Hysteroscopic insemination of small numbers of spermatozoa at the uterotubal junction of preovulatory mares

Mares were inseminated with motile spermatozoa suspended in 30-150 microliters Tyrode's medium directly onto the uterotubal papilla at the anterior tip of the uterine horn, ipsilateral to the ovary containing a dominant preovulatory follicle of > or = 35 mm in diameter, by means of a fine gamete intrafallopian transfer (GIFT) catheter passed through the working channel of a strobed light videoendoscope. Insemination of 10, 8, 25, 14, 11 and 10 mares with, respectively, 10.0, 5.0, 1.0, 0.5, 0.1 or 0.001 x 10(6) motile spermatozoa resulted in conception rates of, respectively, 60, 75, 64, 29, 22 and 10%. Deposition of 1.0 x 10(6) motile spermatozoa onto the uterotubal papilla began to approach the limit of successful fertilization. These doses are far lower than the 3-15 x 10(9) spermatozoa normally ejaculated by fertile stallions during mating, and the accepted minimum dose of 500 x 10(6) spermatozoa used for conventional uterine body insemination in mares. The simplicity of the technique offers a practical means of exploiting new breeding technologies that require very small numbers of spermatozoa in horse breeding.

Hysteroscopic insemination of small numbers of spermatozoa at the uterotubal junction of preovulatory mares

Mares were inseminated with motile spermatozoa suspended in 30-150 microliters Tyrode's medium directly onto the uterotubal papilla at the anterior tip of the uterine horn, ipsilateral to the ovary containing a dominant preovulatory follicle of > or = 35 mm in diameter, by means of a fine gamete intrafallopian transfer (GIFT) catheter passed through the working channel of a strobed light videoendoscope. Insemination of 10, 8, 25, 14, 11 and 10 mares with, respectively, 10.0, 5.0, 1.0, 0.5, 0.1 or 0.001 x 10(6) motile spermatozoa resulted in conception rates of, respectively, 60, 75, 64, 29, 22 and 10%. Deposition of 1.0 x 10(6) motile spermatozoa onto the uterotubal papilla began to approach the limit of successful fertilization. These doses are far lower than the 3-15 x 10(9) spermatozoa normally ejaculated by fertile stallions during mating, and the accepted minimum dose of 500 x 10(6) spermatozoa used for conventional uterine body insemination in mares. The simplicity of the technique offers a practical means of exploiting new breeding technologies that require very small numbers of spermatozoa in horse breeding.

Public policy and state psychiatric hospitals

Professionals who operate from a clinical rather than a political ethic must be prepared to reclaim and accept leadership roles and responsibilities, which have shifted to the political arena.

Ovarian follicular fluid, progesterone and Ca2+ ion influences on sperm release from the fallopian tube reservoir

As a means of determining whether ovarian follicular fluid reaches the functional sperm reservoir in the caudal isthmus of the Fallopian tube shortly after ovulation, 0.01-0.02 ml aliquots of whole or steroid-free follicular fluid were introduced into the distal extremity of the isthmus within 1 hr before ovulation. Eggs were recovered during a second intervention 4 hr 45 min-6 hr 10 min after treatment and examined by phase-contrast microscopy for the normality of fertilisation. In a separate experiment, 0.01-0.02 ml aliquots of 10 microM calcium ionophore solution were introduced into the same site in comparable animals. Sixty-nine fertilised eggs were recovered from 12 fallopian tubes treated with whole follicular fluid, of which 24 (34.8%) were polyspermic. The 12 contralateral control tubes (PBS-treated) yielded 47 fertilised eggs, of which only one (2.1%) was polyspermic (P < 0.001). Steroid-free aliquots of the same follicular fluid introduced bilaterally into eight fallopian tubes (4 animals) resulted in recovery of 59 fertilised eggs, of which only one (1.7%) was polyspermic. Treatment with ionophore solution yielded a 41.6% incidence of polyspermy (10 of 24 eggs from four tubes) compared with 3.8% polyspermy (1 egg) from the control tubes (P < 0.01). Dispermy was the principal form of polyspermy. The numbers of accessory spermatozoa on/in the zona pellucida were increased by the experimental treatment. Follicular fluid passing down the fallopian tube ampulla at ovulation was therefore considered not to be the physiological stimulus for an initial, tightly-controlled release of spermatozoa from epithelial binding in the caudal isthmus. Indeed, because such sperm activation commences shortly before ovulation, a locally transmitted ovarian programming with relatively high concentrations of follicular hormones remains the favoured model. Although pre-ovulatory progesterone is considered to be the coordinating steroid of increasing influence in these pre-fertilisation events, its effects are proposed to be modulated in the endosalpinx by mobilisation of Ca2+ ions into a discrete population of bound spermatozoa. Results of the steroid-free follicular fluid and calcium ionophore treatments stand in support.

Concentrations of energy substrates in oviduct fluid in unilaterally ovariectomised pigs

Nichol et al (1992, Journal of Reproduction and Fertility, 96, 699-707) identified a pre- to post-ovulatory decrease (approx 1 mM) in the amount of glucose in pig oviduct fluid. The present studies investigated whether the decrease was due to metabolism by embryos and/or oviduct tissues, and also whether there was a local influence of the ovary on the oviduct fluid content of energy substrates. Unilaterally ovariectomised pigs were used, in which, through compensation, oviducts that contained twice the normal number of embryos could be compared with oviducts which contained no embryos. Following unilateral ovariectomy and after two oestrous cycles of normal duration, surgery was performed 88 hours after the beginning of standing heat to obtain oviduct fluid samples, just before embryonic entry into the uterus. Luminal fluid samples from the ampulla and ampullary-isthmic junction from oviducts with and without an adjacent ovary were assayed for glucose, pyruvate and lactate concentrations. No significant differences were found between the glucose, pyruvate and lactate concentrations in fluids from the ampulla or ampullary-isthmic junction from oviducts containing embryos compared with absence of embryos (P > 0.05). Therefore, the post-ovulatory decrease was not due to the presence of embryos or to a local effect of the ipsilateral ovary. Consequently, pig oviduct fluid concentrations of glucose, lactate and pyruvate are seemingly regulated by systemic mechanisms.

Regional influences of the fallopian tubes on the rate of boar sperm capacitation in surgically inseminated gilts

Aliquots of ejaculated boar semen containing known numbers of spermatozoa were deposited into the caudal isthmus or rostral ampulla of the Fallopian tubes of gilts at, or immediately after, ovulation to assess regional influences on the rate of capacitation. Eggs were recovered during a second intervention 4, 5, 6 or 7 h after surgical insemination and were examined by phase-contrast microscopy. Results were obtained from ten animals in each of the 4-, 5- and 6-h groups and from eight animals in the 7-h group. With two exceptions, fertilized eggs were not recovered until 6 h after insemination into the isthmus, the proportion (45.6%) being significantly greater than the corresponding figure (1.4%) for ampullary insemination (P < 0.001). Similarly, the proportion of fertilized eggs recovered 7 h after insemination into the isthmus (58.7%) was significantly greater than after ampullary insemination (21.9%; P < 0.01). Numbers of spermatozoa associated with the zona pellucida remained low in all these instances, with mean figures per egg ranging from 0.3 to 3.8. Insemination into the isthmus gave a 1-2 h advantage in fertilization compared with insemination into the ampulla. Although relative rates of sperm cell progression to the site of fertilization may have contributed to this, there is strong evidence that rates of capacitation differ significantly in the respective portions of the Fallopian tube. Therefore, attention was focused on: (1) the viscous glycoprotein secretion in the caudal isthmus acting to remove seminal plasma from the sperm surface; and (2) the phase of sperm head binding to the isthmus epithelium. Gradients in local endocrine modulation by the adjacent ovary offer one explanation for the functional specialization of different regions of the Fallopian tubes.

Have the Fallopian tubes a vital rôle in promoting fertility?

Diverse lines of evidence suggest that the Fallopian tubes make no overwhelming contribution to human reproduction other than as a conduit for gametes and embryos. Even so, bearing in mind global success rates for in vitro fertilization (IVF) coupled with uterine transplantation of embryos (20% fruitful pregnancies), the Fallopian tubes may make a subtle contribution to reproductive performance. The experimental evidence from monkeys and man arguing against an essential rôle for the tubes -- at least in individual instances -- would include (1) the results of Estes' operation, when ovaries are autotransplanted into the uterine lumen in women with blocked or missing Fallopian tubes and pregnancy ensues; (2) asynchronous embryo transfer when newly fertilized (pronucleate) eggs transplanted to the uterus can generate a pregnancy; (3) the transcervical transfer after IVF of early cleavage stage human embryos into the uterus, with subsequent establishment of pregnancy; (4) the trans-cervical transfer of human spermatozoa and oocytes into the uterus to give pregnancy, indicating that capacitation, fertilization and the earliest stages of embryonic development can be achieved in the uterus. In endeavoring to explain contrasts between these successful procedures in primates and their failure in non-primates, perhaps the simplex uterus in primates compared with a bicornuate or bipartite uterus in laboratory and farm species has relevance: there is lack of a clear-cut distinction between the endometrium and endosalpinx in the intra-mural segment and potential mixing of uterine and tubal fluids. Indeed, the latter may explain in part a susceptibility to tubal ectopic pregnancy, coupled with proliferating endometrial fragments in the Fallopian tube.

Long-term stability of the bovine block to polyspermy

Under most circumstances in eutherian mammals, mating occurs before ovulation and a defense against multiple sperm penetration of the zygote is established rapidly after fertilisation. It is generally assumed that this block to polyspermy is both stable and long-lasting, but these points have not been specifically tested. They assume particular significance in domestic farm animals in which procedures of artificial insemination could mistakenly introduce sperm suspensions into a genital tract already containing a fertilised egg. Bovine blastocysts generated in vitro were further exposed in vitro to new suspensions of capacitated bull spermatozoa containing 1.5 x 10(6) cells per ml on days 7 or 8 of development, that is, shortly before or after hatching from the zona pellucida. Inseminated and control blastocysts were examined by light or electron microscopy. Whereas accessory spermatozoa were frequently bound to the surface of the zona pellucida, non had penetrated into the substance of the zona. Similarly, whilst a few spermatozoa had attached to the trophoblast of hatched blastocysts on day 8, none had penetrated through to the blastocoele. No difference was found in the incidence of hatching or rate of expansion between experimental (re-inseminated) and control groups. Accordingly, it is concluded that the bovine block to polyspermy is both stable and long-lasting when tested in vitro in the presence of freshly capacitated bull spermatozoa. Early embryonic loss, which may reach a level of 30% or more in this species, is thus unlikely to be a consequence of instability in the block to polyspermy and accessory sperm penetration of the zygote.

Deep uterine insemination of cattle: a fruitful way forward with smaller numbers of spermatozoa

After describing the site of fertilisation and that of the functional sperm reservoir in the female tract, proposals are made concerning a modified site of sperm deposition in cattle. By means of a deep pre-ovulatory insemination into the ipsilateral uterine horn, the chances should be raised of establishing viable spermatozoa in the isthmus where they would undergo a form of physiological encapsulation and storage. Release and activation of such spermatozoa would be prompted by imminent ovulation. Potential advantages of this approach include those of raising the overall fertility of genetically valuable bulls whose non-return rates are sub-optimal; reducing the number of spermatozoa in each insemination dose; using effectively the limited numbers of sex-selected sperm cells (X and Y chromosome bearing spermatozoa) currently available from flow cytometry. Putative disadvantages might include rectal palpation of the ovaries to locate the pre-ovulatory follicle; perforation of the uterine wall by the deep insemination catheter; risk of polyspermic fertilisation; and the inappropriateness of the technique for non-clinically qualified inseminators. Each of these reservations is responded to in a rational manner. Given a change of attitude, a modified technique of insemination would be feasible under commercial conditions and might give a welcome boost to a sagging artificial insemination industry.

Oviduct fluid pH in intact and unilaterally ovariectomized pigs

The pH of the oviduct lumen was measured at different stages of the estrous cycle in the ampulla and ampullary-isthmic junction (AIJ) of intact and unilaterally ovariectomized mated or nonmated pigs. The pH profile consisted of high frequency small peaks superimposed on low frequency large amplitude peaks. One animal examined at midcycle exhibited fluctuations in pH (peak to nadir; delta pH) of 0.3 and 0.7 units in the ampulla and AIJ, respectively, and the frequencies of the large peaks in these regions were 2.6 and 1.6 peaks.min-1, respectively. In six preovulatory unmated pigs, the delta pH (mean +/- SE) was 0.50 +/- 0.04 units in both regions and the large peak frequencies were 0.6 +/- 0.06 peaks.min-1. In one animal that was assessed during ovulation, the pH showed deviations of up to 0.4 pH units, which were probably due to the alkalinity of follicular fluid accompanying the ovulated eggs. In the ampullae of five unilaterally ovariectomized postovulatory-mated pigs, the delta pH in oviducts with and without an ipsilateral ovary was significantly lower than preovulatory (p < 0.05), but the large and the small peak frequencies were not significantly different. By contrast, the delta pH in the AIJ with an ipsilateral ovary (0.11 +/- 0.02 units) was significantly lower than before ovulation (0.54 +/- 0.04 units) and also when compared with the contralateral AIJ (0.36 +/- 0.06 units) (p < 0.05). The ovary also influenced the small peak frequency, which was significantly higher if the ipsilateral ovary was absent (10.7 +/- 1.5 vs. 14.9 +/- 1.6 peaks.min-1, respectively). Thus, oviduct fluid pH is controlled by both systemic and local mechanisms, and the ipsilateral ovary and (or) embryonic factors influence the pH profile of the oviduct.

Are lower fertility bulls necessarily less fertile? Proposals concerning insemination procedures

This essay argues that current procedures of selection for high fertility bulls may overlook young males of potentially high fertility unless these are tested by modified procedures of insemination. Should this suggestion prove to be true, even if only for a small proportion of young bulls that would not previously have been retained as stud animals, then valuable production genes would be kept in the national herd. Modified procedures of introducing the sperm suspension might include (I) deep intra-uterine insemination, (II) insemination into the functional sperm reservoir in the Fallopian tube isthmus, (III) laparoscopic insemination close to the utero-tubal junction, (IV) intra-peritoneal insemination, (V) insemination under conditions of mild superovulation, and (VI) insemination with smooth muscle stimulants and/or sperm stimulating agents added to the suspension. (VII) The potential value of in vitro fertilization assays, such as the zona-free hamster oocyte sperm incorporation test, is also noted. Even if only one of these approaches were found to be fruitful, its impact could be of major significance for the cattle breeding industry.

Motility of spermatozoa in hydrosalpingeal and follicular fluid of pigs

Hydrosalpinges were created to collect adequate volumes of fluid during pre-, peri- and postovulatory intervals from the ampulla, ampullary-isthmic junction and the isthmic-utero-tubal junction of the oviducts from Large White gilts that had exhibited at least two natural oestrous cycles. The accumulated fluids, follicular fluid and Butschwiler's medium were compared for their effects on various parameters of boar sperm motility using the CellSoft, computer-assisted, digital image analysis system. Sperm velocity (micron s-1 +/- SEM) was significantly higher (P < 0.05) in follicular fluid (84 +/- 3; n = 5) than in fluids from the ampulla during peri- and early postovulatory intervals, and from the isthmic-utero-tubal junction during pre- and early postovulatory intervals. It was also higher (P < 0.05) than in the fluid from the ampullary-isthmic junction during pre- and early postovulatory intervals; however, sperm velocity in follicular fluid was not significantly different from that in the periovulatory fluid from the ampullary-isthmic junction. The mean lateral head displacement (ALHmean) of spermatozoa was significantly greater in follicular fluid (3.9 +/- 0.3 microns; n = 5) than in fluid from the ampulla during peri- and early postovulatory intervals and from the isthmic-utero-tubal junction during pre- and early postovulatory intervals, and was also higher (P < 0.05) than in fluid from the ampullary-isthmic junction during the preovulatory period, but was not different from the peri- and postovulatory ampullary-isthmic junction fluids. The proportion of spermatozoa exhibiting circular motion was significantly higher (P < 0.05) in the periovulatory fluid from the ampullary-isthmic junction (24 +/- 3%) compared with fluids obtained during preovulatory and early postovulatory periods. Follicular fluid had no effect on the proportion of spermatozoa exhibiting circular motion. The average radius of sperm movement in circular trajectories was higher in follicular fluid than in the periovulatory fluids from the ampulla and ampullary-isthmic junction (P < 0.05). In hydrosalpingeal fluids collected 2-5 days after ovulation, the average radius of movement was greater in the ampulla fluid and ampullary-isthmic junction fluid than in fluid from the isthmic-utero-tubal junction (P < 0.05). These results demonstrate that follicular fluid and oviductal fluids have considerable influences on boar sperm motility. Furthermore, the immediate effect of periovulatory ampullary-isthmic junction fluid in increasing the percentage of spermatozoa swimming in circles (hyperactivated) is relevant, since it is at this time and within this region that fertilization occurs.

Graafian follicles are cooler than neighbouring ovarian tissues and deep rectal temperatures

In order to establish appropriate culture temperatures for in-vitro maturation of pig ovarian oocytes, large Graafian follicles (7-10 mm diameter) were sensed by infra-red technology during the latter part of a spontaneous oestrous cycle. Temperatures were measured under systemic anaesthesia almost instantaneously upon revealing the ovaries at mid-ventral laparotomy. Temperature differentials were observed within all 16 ovaries sensed in 14 animals. Ovaries were always cooler than deep rectal temperatures (mean rectal temperature was 38.0 +/- 0.4 degrees C; range 37.5-38.6 degrees C) and mature follicles always cooler than ovarian stroma (35.6 +/- 0.3 degrees C versus 37.3 +/- 0.2 degrees C respectively; P < 0.01). Such follicles were frequently 1.5-1.8 degrees C cooler than the adjacent stroma, the mean being 1.7 +/- 0.4 degrees C. Small Graafian follicles (< 5-6 mm diameter) and recent ovulations did not show this differential. The control experiment of excising an ovary, deep freezing it in liquid nitrogen, and then restoring it to the body cavity before further sensing indicated that intra-ovarian temperature gradients depended on the activity of living tissues and/or a functional blood supply. Furthermore, calculation of anticipated rates of cooling for exposed Graafian follicles strongly suggested that artefacts could not have been solely responsible for the observed temperatures. Endothermic reactions within mature follicles were thus brought into focus. It is concluded that follicular temperatures may influence the meiotic progression and cytoplasmic maturation of oocytes and act to regulate enzymatic activity in the biosynthetic pathways for steroid and/or peptide hormones.

Aetiology of intersexuality in female (XX) pigs, with novel molecular interpretations

This review considers the problem of ovotestis formation in animals of 38,XX chromosome complement. After a clinical description, attention focuses on the condition of the gonads and genital tract. A complete spectrum of gonadal types has been found, ranging from a single ovotestis almost invariably on the right-hand side to both gonads appearing as testicular-like structures, sometimes with a distinct tunica albuginea. The ovotestis or testis-like structure may have descended to an inguinal or scrotal location. Although interstitial cells of Leydig and seminiferous tubules were always abundant in testicular tissue, germ cells were never present. The lumen of the seminiferous tubules was packed with pale-staining, Sertoli-like cells. A bicornuate uterus was characteristic but suppression of the proximal portion of the Müllerian duct always adjoined an ovotestis; a corresponding development of the Wolffian duct featured as a convoluted epididymis. Inhibition of the Fallopian tube was attributed to a local influence of AMH from the Sertoli cells, as was the failure of small Graafian follicles within an ovotestis to respond to injected gonadotrophins. As to the aetiology of an ovotestis, defective colonisation of the genital ridges by primordial germ cells is considered, as is evidence for incorporation of adrenal cells into the embryonic gonad. Molecular probing has failed to reveal the classical sex-determining gene, Sry, and other Y-related DNA sequences such as Zfy and DYZI in almost all the intersex animals examined. Currently favoured as an explanation for ovotestis formation is a mutation in the inhibin gene within granulosa cells of Graafian follicles. Such a mutation would prompt secretion of the closely comparable glycoprotein molecule AMH in these genetic females, with a resultant progressive virilisation of gonadal tissue. The proposed mutation may be carried as an autosomal recessive gene by certain boars. Varying amounts of AMH secretion or differing timescales for the transition from inhibin to AMH could in part explain differing degrees of ovotestis formation. Despite this proposition, interactions between genes that prescribe functional testicular tissue, enhanced rates of gonadal development, and left-right asymmetries between the paired gonads now require systematic study.

Ovarian control of very low sperm/egg ratios at the commencement of mammalian fertilisation to avoid polyspermy

This essay considers the means whereby sperm/egg ratios close to unity are generated during the initial stages of fertilisation in placental mammals. Pre-ovulatory graafian follicles and their contents are seen to be key structures orchestrating the events of sperm progression and coordinating the subsequent meeting of male and female gametes. Three levels of control over the numbers of spermatozoa activated and released from the functional reservoir in the caudal region of the fallopian tube isthmus are proposed. A primary control would be obtained by means of a countercurrent transfer of ovarian follicular progesterone from the ovarian vein into the tubal branch of the ovarian artery. The concentration of progesterone so transferred would be proportional to the number of preovulatory follicles, and thus to the number of eggs to be shed, and would act progressively to reduce sperm binding to the endosalpinx of the caudal isthmus. Differential timing of the release from epithelial binding may be a crucial means of achieving the initial low sperm/egg ratios. a secondary regulation of the release of graded numbers of viable spermatozoa towards the ampullary-isthmic junction of the fallopian tubes would be by means of molecular messages derived from the mucified oocyte-cumulus complex shortly before and after the time of ovulation. Third would be reorientation of sperm trajectories by molecular gradients within the cumulus cell mass to direct competent spermatozoa to those oocytes as yet unpenetrated. Together these differing levels of control would impose low sperm/egg ratios during the initial stages of fertilisation, such strict quantitative regulation of male gametes lasting at least until the block to polyspermy is fully established and the vitellus is no longer at risk from further sperm penetration.

Intersexuality in pigs: clinical, physiological and practical considerations

Veterinary surgeons and practical pig farmers need to be aware of a condition that can have important deleterious consequences in a breeding herd. The animals in question have sometimes been referred to as hermaphrodites but would more correctly be termed intersexes. Whilst there is a complete spectrum of phenotypic sexual development within a population of such animals, the most common form is that of a putative female with a prominent up-turned vulva. Reflection of the vulval lips reveals a much-enlarged clitoris. There may be scrotal development, in conjunction with an enlarged penile and preputial sheath. Coarse hair and incipient tusk development may further indicate differing degrees of masculinization. Surgical exploration of intersex animals confirms a complete spectrum of gonadal types, ranging from 2 ovaries with a proportion of testicular tissue in one of them (i.e., an ovotestis) to 2, much-enlarged testicular-like structures with no detectable ovarian tissue. The gonads usually remain within the abdomen, but those with testicular tissue may descend to an inguinal or even scrotal location. The genital tract invariably comprises a bicornuate uterus, a partially vestigial Fallopian tube, and some development of one or both Wolffian ducts adjoining an ovotestis or testicular-like structure to form a convoluted epididymis. Spermatozoa are never present, either in abdominal or scrotal testicular tissue, nor are there any germ cells within the seminiferous tubules, only Sertoli-like cells. Due to the spectrum of gonadal types, sexual behaviour ranges from male-type aggressivity on the one hand to regular oestrous cycles on the other, with periods of standing oestrus during which intromission may be achieved. In animals with functional ovarian tissue in both gonads, foetal development has been observed, at least until days 25-30 of gestation. Almost all intersex pigs possess XX sex chromosomes and usually 36 autosomes; only a very small proportion are chimaeras or mosaics. Chromosome banding techniques have failed to demonstrate a portion of the Y chromosome translocated onto an X chromosome nor has molecular probing revealed the presence of the sex determining gene Sry or other classical Y-related DNA sequences, except in one instance. Breeding records suggest that the intersex condition results most frequently from the influence of an autosomal recessive gene carried by certain boars. Identification of such boars is therefore essential, as the incidence of intersexuality in their offspring may reach 4-5% or more. In terms of the pig industry, economic losses may result from: 1. Lack of fertility in intersex animals. 2. Aggressive behaviour in groups of growing/fattening pigs. 3. Boar taint in the carcase of animals possessing ovotestis. 4. Propagation of the deleterious condition, either by mating or more widely by artificial insemination.

Client as colleague. Therapeutic contracting with the seriously mentally ill

This article introduces the therapeutic contracting program as a comprehensive treatment system for persons with serious mental illness. Therapeutic contracting offers a promising framework for integrating medical, psychological, and social therapies in a manner that fosters clients' active involvement in treatment. This article outlines a multistage therapy program that mobilizes clients' adaptational resources through experimental interventions, structured goal-setting exercises, and skills-building experiences. Data illustrate the effectiveness of therapeutic contracting for (a) securing clients' treatment compliance, (b) promoting positive clinical outcomes, (c) reducing overall treatment costs. The therapeutic contracting model is discussed as a potential vehicle for expanding the professional role of psychologists in psychiatric settings, particularly in areas of clinical and administrative decision making.

Client as colleague. Therapeutic contracting with the seriously mentally ill

This article introduces the therapeutic contracting program as a comprehensive treatment system for persons with serious mental illness. Therapeutic contracting offers a promising framework for integrating medical, psychological, and social therapies in a manner that fosters clients' active involvement in treatment. This article outlines a multistage therapy program that mobilizes clients' adaptational resources through experimental interventions, structured goal-setting exercises, and skills-building experiences. Data illustrate the effectiveness of therapeutic contracting for (a) securing clients' treatment compliance, (b) promoting positive clinical outcomes, (c) reducing overall treatment costs. The therapeutic contracting model is discussed as a potential vehicle for expanding the professional role of psychologists in psychiatric settings, particularly in areas of clinical and administrative decision making.

Significance of the epithelial crypts at the bovine utero-tubal junction in the pre-ovulatory phase of sperm regulation

Because polyspermic fertilisation is a pathological condition in mammals, arising from an excess of spermatozoa at the site of initial sperm-egg contact and leading to early death of the embryo, consideration has been given to the manner whereby the utero-tubal junction may contribute to a reduction in the numbers of spermatozoa entering the Fallopian tubes. This seems especially important in cattle since the utero-tubal junction does not exhibit swollen polypoid processes that might act physically to reduce the number of spermatozoa entering the isthmus from the uterus. In tissues prepared from animals close to the time of ovulation, large numbers of simple glands were visible in the uterine surface and throughout the region of the utero-tubal junction and its ridges extending into the isthmus. The glands appeared as crypts, slits or craters. On the basis of a figure of 500 glands situated close to the utero-tubal junction and some 2-10 spermatozoa located within each gland, these conservative estimates suggest a temporary arrest of 1-5x10(3) spermatozoa, thereby contributing to the steeply diminishing sperm gradient before the site of fertilisation. There would thus appear to be a vital physical rôle for the simple glands and clefts that predominate in this region, functioning importantly in the pre-ovulatory interval to pave the way for normal monospermic fertilisation. More subtle forms of sperm regulation by glycoprotein molecules are also considered.

Ovarian regulation of sperm progression in the fallopian tubes

Successful liberation and apposition of gametes are essential components of fertility. Normal fertilisation depends upon the establishment of a pre-ovulatory sperm gradient in the female tract between the site of semen deposition and the site of fertilisation in the Fallopian tubes. As a consequence, sperm: egg ratios may be close to unity at the time of activation of most secondary oocytes under conditions of spontaneous mating. In the absence of a sufficient sperm gradient, newly ovulated eggs would be confronted by an excess of spermatozoa resulting in polyspermic fertilisation. Penetration of the vitellus by more than one spermatozoon is pathological in mammals (Beatty, 1957; Austin, 1963). Accordingly, systems that act to regulate sperm progression and competence before the time of ovulation assume a particular importance. During the 1950s, 1960s and 1970s, there was much controversy as to the rate of sperm transport into the Fallopian tubes. Because observations failed to focus on those spermatozoa that could fertilise eggs, the controversy was largely sterile. Nor were the disagreements well founded since some experiments employed artificial insemination whilst others used natural mating. These two quite distinct approaches to introducing a sperm suspension into the female tract could not reasonably form the basis of disagreements on the physiological events of cellular progression. More recent studies have been set in perspective by Overstreet (1983), Harper (1988), Yanagimachi (1988), Hunter (1988, 1991, 1995) and Drobnis & Overstreet (1992)After mating at the onset of oestrus, ram and bull spermatozoa require a minimum of 6–8 h to reach the Fallopian tubes in sufficient numbers to promote suc.cessful fertilisation (Hunter et al., 1980; Hunter & Wilmut, 1982). Spermatozoa displaced to the tubes in a small number of minutes are moribund or dead, not.

Modulation of gamete and embryonic microenvironments by oviduct glycoproteins

Studies on protein molecules in oviduct luminal fluid are viewed historically, and then in terms of more recent studies on a possible involvement of unique glycoproteins in embryonic development. As a caution, however, it is noted that incorporation of such molecules into the vitellus may be nonspecific. The question is raised as to whether oviduct glycoproteins could be acting primarily in a physical sense to stabilize differing chemical environments along the oviduct. Equally or more importantly, glycoproteins might be acting as carrier molecules to present cations and metabolic substrates at appropriate concentrations to the vitelline membrane. This latter possibility is examined in some detail and could be tested by manipulating the composition of the perivitelline fluid. Glycoproteins may also be critically involved in regulating the physiological competence of spermatozoa in the pre- and peri-ovulatory oviduct, in maintaining a coordinated pattern of cilial beat, and in immunosuppressive functions within the oviduct, not least in those associated with the masking of paternal antigens on both spermatozoa and embryos.

Sperm:egg ratios and putative molecular signals to modulate gamete interactions in polytocous mammals

Reasoning from the premises that 1) the sperm:egg ratio at the time of activation of the secondary oocyte in mammals is close to unity under conditions of spontaneous mating, 2) a majority of eggs within the cumulus oophorus of a polytocous species is fertilized in a reasonably short interval of time, and 3) spermatozoa would find it difficult to reverse their approach to the zona pellucida, it is proposed that molecular gradients exist to divert spermatozoa penetrating the cumulus mass away from eggs already activated and towards eggs as yet unfertilized. Possible sources of such molecular cues are considered, as is the event that triggers their release.

Rate of establishment of a fertilising population of spermatozoa in the sheep cervix after a single mating at the onset of oestrus

In order to study how soon a population of spermatozoa capable of fertilisation could progress into the cervical canal, the vaginal contents were flushed with a detergent solution at different intervals after mating at the onset of oestrus. Eggs recovered 1 or 2 days later from the oviducts were stained and examined by phase-contrast microscopy. Flushing at 3 minutes after mating did not prevent fertilisation in 44% of instances, whereas similar flushes performed at 6 or 9 minutes completely prevented fertilisation in a total of 26 animals. In the groups flushed at 12 and 15 minutes, the proportion of eggs fertilised was 21% and 24%, respectively, and this increased to 37% after flushing at 18 minutes. An explanation is offered for the paradoxical finding at 3 minutes, and it is concluded that at least 30-60 minutes would be required for adequate colonisation of the cervix with a fertilising population of spermatozoa under the conditions employed in the experiment. However, multiple matings or mating closer to the time of ovulation might act to reduce this interval.

Concentrations of energy substrates in oviductal fluid and blood plasma of pigs during the peri-ovulatory period

Large White gilts, 9 to 18 months old, that had exhibited at least two natural oestrous cycles were divided into three groups (phases): unmated pre-ovulatory, unmated post-ovulatory and mated post-ovulatory (n = 16, 20 and 18). Oviductal luminal fluid samples were collected under anaesthesia by micropipette from the ampulla and ampullary-isthmic junction and analysed by an ultramicrofluorometric technique. Glucose concentrations (mmol 1(-1), means combining regions; mean +/- SEM) were significantly higher in blood plasma than in oviductal fluid (4.56 +/- 0.20 versus 0.59 +/- 0.16; P < 0.0001; n = 27), whereas lactate was higher in the oviduct (5.71 +/- 0.53 versus 2.48 +/- 0.24; P < 0.0001; n = 27). No significant differences were found between the ampulla and the ampullary-isthmic junction. However, the concentration of glucose was significantly higher (P < 0.05) in the ampulla of the pre-ovulatory group (0.97 +/- 0.20; n = 13) compared with the mated group (0.25 +/- 0.05; n = 14) and its concentration in the ampullary-isthmic junction in the pre-ovulatory group (1.65 +/- 0.63; n = 13) was significantly greater (P < 0.05) than in the post-ovulatory (0.43 +/- 0.11; n = 11) or mated groups (0.17 +/- 0.02; n = 14). Lactate in the ampulla of mated animals was higher than in the pre-ovulatory group (6.83 +/- 0.70 versus 3.86 +/- 0.38; P < 0.05; n = 15 and 13), but neither was significantly different from the post-ovulatory group. Furthermore, no change was seen at the ampullary-isthmic junction in lactate concentration with phase.(ABSTRACT TRUNCATED AT 250 WORDS)

Sarcoidosis of the breast, central nervous system, and exocrine glands in a patient with sicca symptoms

Images

Oviduct function in pigs, with particular reference to the pathological condition of polyspermy

Because the exceptionally high incidence of polyspermic fertilisation has been emphasised as a major defect in systems of in vitro fertilisation in pigs, the aetiology of the condition has been analysed in a series of experiments in vivo in the search for a common underlying cause and possible means of mitigation. Whereas the defense mechanism against polyspermy in pig oocytes is classically viewed as zona reaction, more recent evidence suggests a secondary block at the vitelline surface. Both blocks may be compromised in situations leading to polyspermy, although deleterious influences seem to be expressed principally in an inadequate zona block, as judged by the presence of perivitelline spermatozoa. Postovulatory aging of mammalian oocytes prior to sperm penetration leads to polyspermy, as can be demonstrated in pig eggs. The primary lesion may concern the cortical reaction, owing to a delayed and incomplete exocytosis of the vesicular contents. Eggs ovulated after gonadotrophin treatment during the luteal phase of the cycle show a high incidence of polyspermic penetration (60.6%), as do those shed at estrus in animals treated with progesterone systemically (40%) or by local microinjections in the oviduct wall (32.3%). Whereas progesterone may be modifying interactions of the gametes and responses of the egg organelles in all four above experimental situations, enhanced numbers of spermatozoa ascending a more patent isthmus appear to be the principal cause of polyspermy.(ABSTRACT TRUNCATED AT 250 WORDS)