117 Supplementation of IVF medium with nerve growth factor improved bovine embryonic cleavage rates during summer months

Nerve growth factor-β (NGF), a protein originally associated with regulation of neuron development, has been found to play a role in the reproductive system of mammals. Previous research showed that administration of NGF to cows resulted in enhanced conceptus development. Although these effects were speculated to be a result of improved corpus luteum function, whether NGF could act directly on the embryo remained undetermined. Therefore, the direct effects of NGF on fertilization and embryo development warrant investigation to see whether it can be used as a novel tool to improve cleavage and blastocyst rates when producing embryos via IVF during periods of suboptimal oocyte quality, such as with heat stress. The objective of this study was to explore how supplementation of NGF, purified from bull seminal plasma, during IVF may directly affect embryo development in oocytes harvested in the summer. Abattoir-derived bovine ovaries were used for recovery of cumulus-oocyte complexes (COCs) over eight replicates through May and June. On Day −1, COCs were collected and matured for 20h in oocyte maturation medium incubated at 38.5°C. On Day 0, matured oocytes were added to a solution of IVF-Tyrode's albumin lactate pyruvate (TALP) and either phosphate-buffered saline (PBS; control) or 100ngmL−1 NGF. Pooled frozen-thawed semen from two different bulls per replicate were added to the IVF solutions and incubated with COCs for 20h at 38.5°C in a humidified atmosphere of 5% CO2. On Day 1, zygotes were washed in HEPES-TALP, and cumulus cells were removed using 1% hyaluronidase. The zygotes were plated in synthetic oviductal fluid (SOF-BE2) culture medium and incubated at 38.5°C in a tri-gas chamber (5% CO2, 5% O2, and balanced N2). Cleavage rates were recorded at 24 and 48h, calculated by dividing the number of cleaved embryos by the total zygote count. Embryos were incubated until Day 8, when the rate of blastocysts was assessed. This study found that the treatment of IVF medium with NGF increased the cleavage rate of embryos after 48h (Control: 59%; NGF: 66%; P=0.04) and the hatched blastocyst percentage per oocyte on Day 8 (Control: 6.7%; NGF: 9.4%; P=0.01). The treatment did not affect the percentage of blastocysts per cleaved embryos (Control: 21%; NGF: 22%; P=0.16) or the hatched blastocyst rate at Day 8 (Control: 53%; NGF: 55%; P=0.67). These results show that NGF can act directly on the oocyte during fertilization to alter subsequent development, specifically through increased embryonic cleavage rates. Further studies are needed to assess different dosages of NGF in order to mitigate the detrimental effects of heat stress on oocyte competence for use in IVF. Follow-up studies using a whole-animal model are needed to understand the clinical relevance of these findings in the ability of embryos to promote maternal recognition of pregnancy.

Mind the gap: is it time to invest in embedded researchers in regional, rural and remote health services to address health outcome discrepancies for those living in rural, remote and regional areas?

Research capacity building in healthcare works to generate and apply new knowledge to improve health outcomes; it creates new career pathways, improves staff satisfaction, retention and organisational performance. While there are examples of investment and research activity in rural Australia, overall, rural research remains under-reported, undervalued and under-represented in the evidence base. This is particularly so in primary care settings. This lack of contextual knowledge generation and translation perpetuates rural-metropolitan health outcome disparities. Through greater attention to and investment in building research capacity and capability in our regional, rural and remote health services, these issues may be partially addressed. It is proposed that it is time for Australia to systematically invest in rurally focussed, sustainable, embedded research capacity building.

Implementation of an older person's nurse practitioner in rural aged care in Victoria, Australia: a qualitative study

BACKGROUND

There are staff shortages nation-wide in residential aged care, which is only predicted to grow as the population ages in Australia. The aged care staff shortage is compounded in rural and remote areas where the health service workforce overall experiences difficulties in recruitment and retention. There is evidence that nurse practitioners fill important service gaps in aged care and rural health care but also evidence that barriers exist in introducing this extended practice role.

METHODS

In 2018, 58 medical and direct care staff participated in interviews and focus groups about the implementation of an older person's nurse practitioner (OPNP) in aged care. All 58 interviewees had previously or currently worked in an aged care setting where the OPNP delivered services. The interviews were analysed using May's implementation theory framework to better understand staff perceptions of barriers and enablers when an OPNP was introduced to the workplace.

RESULTS

The major perceived barrier to capacity of implementing the OPNP was a lack of material resources, namely funding of the role given the OPNP's limited ability to self-fund through access to the Medicare Benefits Schedule (MBS). Staff perceived that benefits included timely access to care for residents, hospital avoidance and improved resident health outcomes.

CONCLUSION

Despite staff perceptions of more timely access to care for residents and improved outcomes, widespread implementation of the OPNP role may be hampered by a poor understanding of the role of an OPNP and the legislative requirement for a collaborative arrangement with a medical practitioner as well as limited access to the MBS. This study was not a registered trial.

Benefits of the 'village': a qualitative exploration of the patient experience of COPD in rural Australia

OBJECTIVES

This study sought to explore patients' experiences of living with, and adapting to, chronic obstructive pulmonary disease (COPD) in the rural context. Specifically, our research question was 'What are the barriers and facilitators to living with and adapting to COPD in rural Australia?'

DESIGN

Qualitative, semi-structured interviews. Conversations were recorded, transcribed verbatim and analysed using thematic analysis following the COnsolidated criteria for REporting Qualitative research guidelines.

SETTING

Patients with COPD, admitted to a subregional hospital in Australia were invited to participate in interviews between October and November 2016.

MAIN OUTCOME MEASURES

Themes were identified that assisted with understanding of the barriers and facilitators to living with, and adapting to, COPD in the rural context.

RESULTS

Four groups of themes emerged: internal facilitators (coping strategies; knowledge of when to seek help) and external facilitators (centrality of a known doctor; health team 'going above and beyond' and social supports) and internal/external barriers to COPD self-management (loss of identity, lack of access and clear communication, sociocultural challenges), which were moderated by feelings of inclusion or isolation in the rural community or 'village'.

CONCLUSIONS

Our findings suggest that community inclusion enhances patients' ability to cope and ultimately self-manage COPD. This is facilitated by living in a supportive 'village' environment, and included a central, known doctor and a healthcare team willing to go 'above and beyond'. Understanding, or supplementing, these social networks within the broader social structure may assist people to manage chronic disease, regardless of rural or metropolitan location.

Women with fear of childbirth might benefit from having a known midwife during labour

AIM

Having a known midwife at birth is valued by women across the world, however it is unusual for women with fear of childbirth to have access to this model of care. The aim of this study was to describe the prevalence and factors related to having access to a known midwife for women referred to counseling due to childbirth fear. We also wanted to explore if women's levels of childbirth fear changed over time.

METHODS

A pilot study of 70 women referred to counseling due to fear of birth in 3 Swedish hospitals, and where the counseling midwife, when possible, also assisted during labour and birth.

RESULTS

34% of the women actually had a known midwife during labour and birth. Women who had a known midwife had significantly more counseling visits, they viewed the continuity of care as more important, were more satisfied with the counseling and 29% reported that their fear disappeared. Fear of birth decreased significantly over time for all women irrespective of whether they were cared for in labour by a known midwife or not.

CONCLUSIONS

Although the women in the present study had limited access to a known midwife, the results indicate that having a known midwife whom the women met on several occasions made them more satisfied with the counseling and had a positive effect on their fear. Building a trustful midwife-woman relationship rather than counseling per se could be the key issue when it comes to fear of birth.

A randomized controlled study comparing internet-based cognitive behavioral therapy and counselling by standard care for fear of birth - A study protocol

Fear of birth is a concern that requires evidence based treatment. The aim of this study is to present the protocol of a randomized controlled multi-center trial to compare internet-based cognitive therapy with counseling as standard care for pregnant women reporting fear of birth. Participants will be recruited in mid-pregnancy. Women who score 60 or above on the Fear of Birth Scale will be offered to participate in this study. Data will be collected by questionnaires including validated instruments at baseline and follow-ups at gestational weeks 30 and 36, two months and one year after birth. The primary outcome will be level of fear of birth measured with the Fear of Birth Scale at 36 weeks of gestation. Secondary outcome measures are level of fear of birth at two months and one year after giving birth, preferences for mode of birth, requests for elective cesarean section, compliance and satisfaction with treatment and birth outcomes. A power calculation based on a 20% reduction of fear implies that approximately 200 will be included in the trial. The study outlined in this protocol will be the first randomized controlled trial comparing internet-based cognitive therapy with counseling for women reporting fear of birth. An effective treatment may result in better overall health for women with fear of birth and a reduction in cesarean sections for non-medical reasons. Evidence regarding treatment options of fear of birth will also provide a greater choice for women.

Implementation of Shared Decision-Making in Australia

Shared decision-making (SDM) is the process of clinicians and patients participating jointly in making healthcare decisions, having discussed evidence-based treatment options and the potential risks and benefits of each option, taking into consideration the patient’s individual preferences and values. SDM is ubiquitous in Australian healthcare policy. While there is good evidence for utilising SDM, clinicians’ knowledge of SDM, the current uptake, effectiveness and acceptability of SDM in Australia is largely unknown. The challenges perceived by clinicians to implementing SDM in clinical practice and potential moral, legal and ethical dilemmas require further debate and consideration. Abbreviations: SDM – Shared Decision-Making.

Swedish women's interest in models of midwifery care - Time to consider the system? A prospective longitudinal survey

BACKGROUND

Sweden has an international reputation for offering high quality maternity care, although models that provide continuity of care are rare. The aim was to explore women's interest in models of care such as continuity with the same midwife, homebirth and birth center care.

METHODS

A prospective longitudinal survey where 758 women's interest in models such as having the same midwife throughout antenatal, intrapartum and postpartum care, homebirth with a known midwife, and birth center care were investigated.

RESULTS

Approximately 50% wanted continuity of care with the same midwife throughout pregnancy, birth and the postpartum period. Few participants were interested in birth center care or home birth. Fear of giving birth was associated with a preference for continuity with midwife.

CONCLUSIONS

Continuity with the same midwife could be of certain importance to women with childbirth fear. Models that offer continuity of care with one or two midwives are safe, cost-effective and enhance the chance of having a normal birth, a positive birth experience and possibly reduce fear of birth. The evidence is now overwhelming that all women should have maternity care delivered in this way.

Statewide dissemination of a rural, non-chain restaurant intervention: adoption, implementation and maintenance

The obesity epidemic calls for greater dissemination of nutrition-related programs, yet there remain few studies of the dissemination process. This study, guided by elements of the RE-AIM model, describes the statewide dissemination of a simple, point-of-purchase restaurant intervention. Conducted in rural counties of the Midwest, United States, the study targeted randomly selected, non-chain, family-style restaurants. Owners were recruited through mail, then telephone follow-up. Data were collected through telephone at baseline, and 3, 6, 12 and 18 months post-adoption. Using mixed methods, measures captured the program adoption rate, characteristics of adopters and non-adopters, program implementation and maintenance issues, and owner and customer satisfaction. Analyses involved descriptive statistics and summaries of qualitative data. The program adoption rate was 28%. Adopters were similar to responding non-adopters demographically, but varied in attitudes. The majority of restaurants maintained the program for at least 12 months. Adopters and their customers expressed satisfaction with the program. With some adjustments, the RE-AIM model was helpful in guiding evaluation of this process. Results provide implications for future dissemination of this and other programs with regard to research procedures and potential barriers that may be encountered. Research on alternative strategies for widespread dissemination of such programs is needed in this and other settings.

Comparison of breastfeeding in rural areas of Sweden and Australia - a cohort study

BACKGROUND

Breastfeeding rates in Sweden and Australia appears to be decreasing in both countries. National statistics shows that 87% of infants in Sweden and 73% in Australia receive any breastfeeding two months of age.

AIM

To compare women's experiences of breastfeeding in Sweden and Australia and to identify factors associated with breastfeeding two months after birth.

METHODS

A cohort study in two rural hospitals in mid Sweden (n=300) and north-eastern Victoria in Australia (n=91) during 2007-2009. Participants responded to questionnaires in mid pregnancy and two months after birth. Crude and adjusted odds ratios with a 95% confidence interval were used to detect differences between women in both cohorts.

FINDINGS

Women in Sweden (88.3%) were more likely to report any breastfeeding of the baby two months after birth (OR 2.41; 95% CI: 1.33-4.38) compared to women in Australia (75.8%) but were less satisfied with breastfeeding support and information. The most important factor associated with breastfeeding at two months postpartum for the Swedish women was to have received sufficient information about breastfeeding on the postnatal ward (OR 2.3; 95% CI 1.41-4.76) while for the Australian women receiving the best possible help when breastfeeding for the first time was most important (OR 4.3; 95% CI 1.50-12.46).

CONCLUSION

The results indicate that Swedish women were more likely than their Australian counterparts to breastfeed the baby two months after birth. The findings demonstrated the importance of sufficient information and help when breastfeeding is initiated.

Womens' attitudes and beliefs of childbirth and association with birth preference: a comparison of a Swedish and an Australian sample in mid-pregnancy

BACKGROUND

the rate of caesarean in Australia is twice that of Sweden. Little is known about women's attitudes towards birth in countries where the caesarean rate is high compared to those where normal birth is a more common event.

OBJECTIVES

to compare attitudes and beliefs towards birth in a sample of Australian and Swedish women in mid-pregnancy.

PARTICIPANTS

women from rural towns in mid Sweden (n=386) and north-eastern Victoria in Australia (n=123).

METHODS

questionnaire data was collected from 2007 to 2009. Levels of agreement or disagreement were indicated on sixteen attitude and belief statements regarding birth. Principal components analysis (PCA) identified the presence of subscales within the attitudes inventory. Using these subscales, attitudes associated with preferred mode of birth were determined. Odds ratios were calculated at 95% CI by country of care.

RESULTS

the Australian sample was less likely than the Swedish sample to agree that they would like a birth that: 'is as pain free as possible' OR 0.4 (95% CI: 0.2-0.7), 'will reduce my chance of stress incontinence' OR 0.2 (95% CI: 0.1-0.8), 'will least affect my future sex life' OR 0.3 (95% CI: 0.2-0.6), 'will allow me to plan the date when my baby is born' OR 0.4 (95% CI: 0.2-0.7) and 'is as natural as possible' OR 0.4 (95% CI: 0.2-0.9). They were also less likely to agree that: 'if a woman wants to have a caesarean she should be able to have one under any circumstances' OR 0.4 (95% CI: 0.2-0.7) and 'giving birth is a natural process that should not be interfered with unless necessary' OR 0.3 (95% CI: 0.1-0.7). Four attitudinal subscales were found: 'Personal Impact of Birth', 'Birth as Natural Event', 'Freedom of Choice' and 'Safety Concerns'. Women who preferred a caesarean, compared to those who preferred a vaginal birth, across both countries were less likely to think of 'Birth as a natural event'.

KEY CONCLUSIONS

the Australian women were less likely than the Swedish women to hold attitudes and beliefs regarding the impact of pregnancy and birth on their body, the right to determine the type of birth they want and to value the natural process of birth. Women from both countries who preferred caesarean were less likely to agree with attitudes related to birth as a natural event.

Characterizing the chromosomes of the Australian model marsupial Macropus eugenii (tammar wallaby)

Marsupials occupy a phylogenetic middle ground that is very valuable in genome comparisons of mammal and other vertebrate species. For this reason, whole genome sequencing is being undertaken for two distantly related marsupial species, including the model kangaroo species Macropus eugenii (the tammar wallaby). As a first step towards the molecular characterization of the tammar genome, we present a detailed description of the tammar karyotype, report the development of a set of molecular anchor markers and summarize the comparative mapping data for this species.

Validating a framework for participatory ergonomics (the PEF)

Participatory ergonomics is reported in an increasing number of case studies, but there is little evidence of emerging supportive theory and relatively little generic advice or guidance. The paper describes an effort to provide clarity and organization to the field of participatory ergonomics. A framework has been developed to define a range of different participatory ergonomics initiatives, establishing a number of levels at which to operate. This participatory ergonomics framework (the PEF) was validated through retrospective description of seven independently conducted case studies and through peer evaluation. The exercise suggests that the PEF can be used as a first basis to produce practical guidance on participatory ergonomics programmes.

Variation of codons 1961 and 2177 of the Stargardt disease gene is not associated with age-related macular degeneration

OBJECTIVES

To investigate the role of 2 specific alleles of the Stargardt disease gene (ABCA4) in the pathogenesis of age-related macular degeneration (AMD). Secondary objectives were to investigate differences in frequency of the G1961E allele in selected ethnic groups as well as to examine the segregation of both G1961E and D2177N alleles in 5 multiplex families with AMD.

METHODS

Five hundred forty-four patients with AMD and 689 controls were ascertained from 3 continents. Blood samples from 62 normal individuals of Somalian ancestry were also obtained. Participants were screened for the presence of these ABCA4 alleles with a combination of restriction digestion and single-strand conformation polymorphism analysis of polymerase chain reaction amplification products. Detected alleles were confirmed by DNA sequencing. The number of subjects exhibiting the G1961E or D2177N variants were compared between AMD and control groups using a 2-tailed Fisher exact test.

RESULTS

There was no significant difference (P >.1) in the frequency of the G1961E and D2177N alleles in patients with AMD (2.2%) vs controls (1.0%). In contrast, there was a significant difference (P< .001) in the frequency of the G1961E alleles between normal individuals of Somali ancestry (11.3%) and normal individuals from other populations (0.4%). There was no evidence of cosegregation of these alleles and the AMD phenotype in the 5 multiplex families with AMD examined. These two ABCA4 alleles were slightly more frequent in patients with AMD with choroidal neovascularization (2.7%) than those without this complication (2.5%).

CONCLUSIONS

Somali ancestry is more than 100 times more strongly associated with presence of the G1961E allele than the AMD phenotype. This study did not find any statistically significant evidence for involvement of the G1961E or D2177N alleles of the ABCA4 gene in AMD.

CLINICAL RELEVANCE

The ABCA4 gene is definitively involved in the pathogenesis of Stargardt disease and some cases of photoreceptor degeneration. However, it does not seem to be involved in a statistically significant fraction of AMD cases.

Safety pictograms: are they getting the message across?

This study set out to investigate the role of pictograms in conveying consumer safety information. The experimental work was carried out in two parts. The first part investigated UK comprehension levels of 13 product related pictograms. A new method of judging levels of comprehension of the pictograms was developed. In general the pictograms surveyed were found to be poorly understood, particularly those which were abstract in nature. The second part of the research investigated the effect of different warning styles on noticeability and intended compliance. This was tested using the new European Standard pictogram developed to convey the small parts warning on toys. The effect on parents' intended purchase decisions of different pictograms and or text messages was investigated. Results indicated that parents' decisions on toy suitability were influenced by the perceived hazardousness of the product rather than warnings, regardless of their design. The paper discusses the advantages and limitations of pictograms as a method for conveying consumer information and makes recommendations for their effective use.

Antiviral activity of a sulphated polysaccharide from the red seaweed Nothogenia fastigiata

The antiviral activity of polysaccharide fractions obtained from water extracts of the red seaweed Nothogenia fastigiata was investigated. Fraction F6, corresponding to a sulphated xylomannan, was found to inhibit efficiently the replication of herpes simplex virus type 1 (HSV-1). Furthermore, F6 selectively inhibited the replication of several other enveloped viruses including herpes simplex virus type 2, human cytomegalovirus (HCMV), respiratory syncytial virus, influenza A and B virus, Junin and Tacaribe virus and simian immunodeficiency virus. F6 was only weakly active against human immunodeficiency virus type 1 and 2. The mode of action of F6 against HSV-1 and HCMV could be ascribed to an inhibitory effect on virus adsorption.

Glomerular filtration rate and plasma solutes in BALB/c mice infected with Plasmodium berghei

Immune-complex glomerular nephritis (ICGN) is known to develop during malarial infections, but little is known of its impact on renal function. A total of 24 male BALB/c mice were infected with Plasmodium berghei, and measurements of the glomerular filtration rate (GFR), parasitemia, and plasma solute concentrations were made on days 0, 7, 14, and 19 post-infection. Identical observations were made on 24 uninfected controls. The GFR declined progressively in infected mice from a mean of 201 +/- 2.1 (day 0) to 51 +/- 3 microliters/min (day 19), whereas parasitemia rose to 47% +/- 4.2% infected erythrocytes. In controls, the GFR remained unchanged, averaging 205 +/- 3.4 microliters/min. Plasma osmolality rose in infected mice (326 +/- 1 vs 310 +/- 0.6 mosmol/kg in controls) as a result of increased chloride (123 +/- 0.7 vs 117 +/- 0.6 mEq/l) and urea (17.8 +/- 2.8 vs 9.3 +/- 0.7 mM/l levels). The data reveal a substantial deterioration of renal function during the course of a malarial infection that is short of outright renal failure.

Glomerular filtration rate in wild house mice, Mus musculus, acclimated to water scarcity

1. A single injection technique for GFR (14C-methoxyinulin clearance) was adapted for use in small mammals and applied to wild house mice (Mus musculus). 2. GFR in controls was 247 +/- 14(SE) microliter/min while that of mice acclimated to water shortage was reduced some 44%.

Fluid compartmentation in skeletal muscle and carcass of Mus musculus acclimated to water scarcity

1. Total water (TW), and extracellular water (ECW) (as sodium and chloride space) were determined in skeletal muscle and carcass of Mus musculus acclimated to long-term water shortage. 2. The presence of fat in control mice and those in early stages of acclimation resulted in an apparent increase in TW and ECW as acclimation proceeded. 3. In contrast, fluid volumes per fat-free weight were either unchanged from controls or reduced. 4. Sodium space exceeded chloride space. 5. Muscle and carcass had essentially the same pattern of fluid shifts. 6. We conclude that ECW maintenance is a preeminent component of the acclimation process in this species.

Blocked herpes simplex virus type 2-specific DNA synthesis in simian virus 40-transformed hamster cells permissive for herpes simplex virus type 1

Simian virus 40-transformed hamster cells (LL-1) permissive to herpes simplex virus type 1 (HSV-1) were shown to be relatively nonpermissive to HSV-2. When LL-1 cells were infected with HSV-2, there was a 3- to 4-log reduction in infectious viral progeny at 24 h postinfection as compared with HSV-1 under identical cultured conditions. HSV-2 could be carried in the LL-1 cell line for up to 12 passages without any appreciable cytopathology. Various early functions of the replicative cycle of HSV-2 appeared to be normal. Experiments demonstrated that early enzyme activity, HSV-2 thymidine kinase, and DNA polymerase appeared at permissive levels in extracts of HSV-2-infected LL-1 cells. However, DNA analysis of HSV-2 infected LL-1 cells demonstrated a block in HSV-2-specific DNA synthesis, although HSV-2 was capable of inhibiting DNA synthesis in LL-1 cells. Furthermore, indirect immunofluorescence studies indicate that late HSV-2 structural protein synthesis was inhibited in infected LL-1 cells. Thus, the inability of HSV-2 to replicate in LL-1 cells is due to a block at or before HSV-specific DNA synthesis, resulting in a reduction of the structural protein synthesis required for viral maturation.

The acute retinal necrosis syndrome. Part 2: Histopathology and etiology

The acute retinal necrosis syndrome is manifested by diffuse uveitis, vitritis, retinal vasculitis, and acute necrotizing retinitis (see Part 1). We studied the histopathology and electron microscopic findings of an eye enucleated from a 67-year-old man with typical acute retinal necrosis. Histology showed profound acute necrosis of the retina, retinal arteritis, and eosinophilic intranuclear inclusions in retinal cells. Electron microscopy demonstrated a herpes group virus in all layers of affected retina. The implications of these findings for antiviral and other treatments are discussed.

Kaposi's sarcoma: absence of cytomegalovirus antigens

Using an immunohistochemical method, we could not detect cytomegalovirus antigens in the tissue of Kaposi's sarcoma but could in the cells of control sections from tissues known to be infected by that virus. Our results are consistent with the hypothesis that high antibody titers to cytomegalovirus found in patients with Kaposi's sarcoma are not due to infection of neoplastic cells by the virus, as a secondary event; our data supports the conclusions of others that exposure to cytomegalovirus may be a primary event in the pathogenesis of Kaposi's sarcoma.

Demonstration of interference between dengue virus types in cultured mosquito cells using monoclonal antibody probes

Cultured Aedes albopictus cells (clone C6/36), persistently infected (PI) with dengue virus type 1 (dengue-1) were found resistant to superinfection with dengue virus type 3 (dengue-3). This was determined by indirect immunofluorescent (IF) staining of cultures using monoclonal antibody against a dengue-3 type-specific antigen. Dengue-1 PI cultures stained with this antibody 3 days after superinfection with dengue-3 virus (m.o.i of 2) had dengue-3 antigen in 0.1 to 1.0% of the cells. Control cultures infected with dengue-3 at the same multiplicity contained dengue-3 antigen in greater than 90% of the cells. The resistance to superinfection was not interferon-mediated, and occurred within 20 h after primary infection. In cultures simultaneously infected with two dengue virus types, one virus type was excluded from replication in most cells. A small population of cells was also found (about 1%) that contained type-specific antigen of both dengue virus types.

Characterization of a reptilian epithelioid skin cell line derived from the green sea turtle, Chelonia mydas

A continuous line of epithelioid cells was established from explant skin tissues of the green sea turtle, Chelonia mydas. These cells, designated GTS, have been subcultured more than 60 times in commercially available mammalian cell culture medium supplemented with 5% bovine calf serum. Of those temperatures tested, optimal growth was achieved at 30 degrees C although replication occurred between 16 and 37 degrees C. These cells may be held as monolayers at 8 degrees C or stored frozen in growth medium containing 10% dimethyl-sulfoxide at -70 or -196 degrees C. The modal number of 55 chromosomes per cell is in agreement with the heterogametic female diploid number of this species. The GTS line represents the first established culture of normal epithelioid skin cells to be reported for a poikilothermic species.

Sodium metabolism during acclimation to water restriction by wild mice, Mus musculus

Changes in sodium and potassium balance and urinary aldosterone excretion (free plus "acid labile") were surveyed in house mice acclimating initially to 1/2 the ad libitum water ration and later to 1/4 of ad libitum. Each water restriction caused negative sodium and potassium balance, followed by conservation of both ions. At the first water restriction, negative balance was produced by natriuresis and kaliuresis, at successive water restriction, a negative balance was due to a decrease in food consumption. Aldosterone excretion doubled at the 1/2 ad libitum restriction, and then generally remained at control levels thereafter. Fractional intestinal absorption of both ions showed a persistent increase after the 3rd day of water restriction. The Na:K ratio in urine and feces declined as mice responded to each water restriction and returned to control levels in acclimated animals.

Ineffectiveness of topical adenine arabinoside 5'-monophosphate in the treatment of recurrent herpes simplex labialis

The ability of topical 10 per cent adenine arabinoside 5'-monophosphate to decrease the severity and frequency of recurrent herpes simplex labialis was evaluated in a double-blind, randomized study of 233 patients at three collaborating institutions. Nine clinical and four virologic measurements were used to evaluate drug efficacy during a single episode. No statistically significant improvement in any measurement was seen in the drug-treated patients. Analyses according to institution and age, stage and size of lesion before therapy also indicated no benefit attributable to the drug. There was no effect of the drug on the rate of recurrence of herpes simplex labialis. We conclude that, despite activity against herpes simplex virus infection in tissue culture and in some laboratory animal models, topical use of the drug is ineffective against recurrent herpes simplex labialis. This may be due to failure of the drug to penetrate the skin.

Body fluid distribution in wild Mus musculus acclimated to water restriction

Total body water (TBW), extracellular volume (ECV), and plasma volume (PV) were measured in wild house mice acclimated to chronic water shortage and compared to the same measures in mice exposed acutely to water shortage. Chronic mice were either steady state (SS), i.e., completely acclimated, or nonsteady state (NSS), i.e., transitional. Water shortage was imposed sequentially--1/2, 1/4, and 1/8 ad lib., and no water. SS mice lost solids and cellular fluid at each level of restriction, but maintained plasma volume and partially defended extracellular volume. Acute restriction to 1/2, 1/4, and 1/8 ad lib. caused proportional losses of solids and fluids with the predominant fluid loss being extracellular. Acute restriction to no water caused cellular dehydration plus a loss of extracellular fluids including plasma. Comparison of acute and NSS mice at identical levels of restriction showed the NSS groups to be preacclimated toward further water restriction. Discussion centers on the comparison of acclimated and nonacclimated animals, mechanism of PV defense, and the general process of acclimation.

Blood respiratory properties of Bison bison

The respiratory properties and basic hematology of blood from seven adult bison and one calf were determined. Average oxygen-carrying capacity was 22.2 ml/100 ml blood from adults and 17.0 in calf blood; hemoglobin averaged 17.1 g/100 ml in adults and 13.6 in the calf. Half saturation of the blood occurred at 32mm Hg Po2 at pH 7.40 and 37 degrees C. The average Bohr effect was -0.40. Erythrocytes numbered 8.6 X 10(6)/mm3 and were 52 micron 3 in mean volume. Adult and calf cells differed in mean cell hemoglobin, adults 19.9 pg/cell vs 15.9 in the calf, and this difference evidently caused differences in Haldane effect, standard bicarbonate, and buffering capacity. Bison are capable of prolonged running. Two features of the blood that promote this capacity are its comparatively great oxygen-carrying capacity and low oxygen affinity.

Effect of water temperature on a herpesvirus infection of sea turtles

The role of water temperature in the induction and maintenance of a dermal herpesvirus infection (gray-patch disease) of young, green sea turtles (Chelonia mydas) was studied under carefully controlled experimental conditions, in which the influence of other recognized stress factors was negligible. A nimals that were subjected to a gradual temperature increase from 25 to 30 degrees C, with subsequent maintenance at 30 degrees C, and those that were abruptly shifted from water at 25 degrees C to water at 30 degrees C showed a significantly shorter period before the onset of clinical signs and an increase in the severity of the lesions when compared with control animals. Animals that were subjected to a gradual increase in water temperature from 25 to 30 degrees C and a subsequent decrease to 25 degrees C, where they were maintained, had a period before onset of clinical signs and severity closer to that of control animals. Our findings indicate that both the induction of clinical gray-patch disease and the severity of the lesions are affected by water temperature and suggest that one possible means of control of this herpesvirus infection under intensive aquaculture conditions might be water temperature manipulation.

Viral diseases of the skin, 1975: a 25-year perspective

Most of the major advances in modern virology during the past 25 years have been due principally to the development of refined laboratory techniques and tools and have provided a fund of new knowledge and information about the nature of viral infection and pathogenesis. One group of viruses of interest to dermatologists, the herpesviruses, is undergoing intensive biochemical investigation to determine whether it is carcinogenic. As a result of the success of the World Health Organization's campaign to eradicate smallpox, it is predicted that by the end of 1976, smallpox will have been eradicated. Other viruses of dermatologic interest which are now being studied include the agents of warts, molluscum contagiosum, cat-scratch disease, and enteroviruses. Current research in the field of viral chemotherapy may provide the basis for successfully treating these diseases in the future.

Nuclear membrane changes in herpes simplex virus-infected BHK-21 cells as seen by freeze-fracture

The freeze-fracture technique, which produced high-resolution replicas of large internal faces of membranes, was used for an ultrastructural study of the nuclei of herpes simplex virus-infected BHK-21 cells and mock-infected controls. Crystalline arrays of viral nucleocapsids were found in the nucleoplasm of infected cells, and numerous nuclear membrane "blebs" and protrusions were observed. The numerous areas of membrane distortions were not found to contain nuclear pores. In addition, specific areas of normal protein intramembranous particles are deleted from certain areas of the nuclear membrane as a result of herpes simplex virus, type 2, infection.

A herpesvirus-type agent associated with skin lesions of green sea turtles in aquaculture

Nine successive groups of green sea turtles (Chelonia mydas) were observed in aquaculture during the posthatchling period. During the first 6 months of growth, each group underwent an epizootic of skin lesions, named gray-patch disease. Two types of skin lesions are associated with gray-patch disease: papules and, more characteristically, spreading gray patches which appear 7 to 8 weeks after hatching. In both types of lesions, intranuclear inclusions are found in keratinocytes in the malpighian layer of the epidermis. Electron microscopic examination of scrapings from lesions and biopsies revealed many viral particles, with features characteristic of the herpesvirus group. Transmission of gray-patch disease is possible with bacteria-free preparations of viral particles.