Movement of Ixodes pacificus and Dermacentor occidentalis (Acari: Ixodidae) adult ticks in chaparral under natural conditions in Northern California, U.S.A.

The movement of Ixodes pacificus and Dermacentor occidentalis adult ticks down a hill slope under natural conditions was investigated using the mark-release-recapture (MRR) method. We evaluated the movement of host-seeking adult ticks down a hill slope to determine if ticks travel downhill from an uphill area to trail margins below. During the tick seasons in 2016-2018, the ticks were collected by flagging, marked with paint, released at a predetermined location, and recaptured by weekly flagging. Of the 188 female and 114 male I. pacificus marked and released 30 m above the trail in 2016, 11 (5.8%) females and one (0.9%) male were recaptured at the trail. In 2017, of the 71 female and 52 male I. pacificus, none were recaptured. In 2018, nine (3.6%) female and one (0.4%) male I. pacificus were recaptured of the 247 female and 287 males marked and released. Fifteen (18.5%) female and six (7.3%) male D. occidentalis were recaptured of the 81 females and 82 males marked and released in 2017. The trail deterred further movement with only 0.6% of I. pacificus and 8.3% of D. occidentalis recaptured on the opposite side of the trail. This study demonstrated that some I. pacificus and D. occidentalis adults found along the uphill side of trails may have originated from an area 30 m from the trail margin, some travelling at a rate of 1.6-1.9 m/day under natural conditions in chaparral.

Epidermal growth factor variations in amniotic membrane used for ex vivo tissue constructs.

INTRODUCTION: The amniotic membrane (AM) is used for engineering ex vivo tissue constructs used in ocular surface reconstruction. Epidermal growth factor (EGF) content of the AM is believed to play a key role in supporting corneal epithelial cell expansion on AM. This study investigated EGF content in AM in relation to intra- and inter-donor variations and the effect of processing and preservation (handling). METHODS: Fifteen human AM, both fresh and handled, were analyzed for EGF gene and protein expression by real-time polymerase chain reaction and ELISA, respectively. RESULTS: EGF gene expression was predominantly seen in the AM epithelium (p<0.01). Similarly, EGF protein too was predominantly seen in the epithelial layer (p<0.01) for fresh and handled samples. EGF protein content varied between membranes (inter-donor) and at different sites within the same membrane (intra-donor). The highest EGF protein concentration was noted in the AM apical and mid-region epithelium. Significant EGF protein loss (p<0.01) was observed after handling. CONCLUSION: There is a considerable variation in EGF content between and within donors. This is further affected by handling of the AM. Such variations could affect the clinical efficacy of tissue constructs. Current use of AM for ex vivo expansion of epithelial cells is not standardized and remains an area of concern.

Optimization of amniotic membrane (AM) denuding for tissue engineering.

INTRODUCTION: Amniotic membrane (AM) has gained increasing popularity as a useful carrier for ex vivo-expanded cells for tissue engineering, particularly in ocular surface reconstruction. However, current methods employed for denuding AM are highly variable, and the consequent effects on the structural and molecular composition of the AM basement membrane (BM) are ambiguous. We compare the effects of the main denuding procedures, and propose a highly effective standardized alternative. METHODS: AMs preserved for transplantation were denuded using published ethylenediaminetetraacetic acid (EDTA)- and dispase-based methodologies and our novel thermolysin-based procedure. Scanning and transmission electron microscopy and immunohistochemistry, for BM components (collagens IV and VII, laminin 5, and integrins alpha6 and beta4), were used to assess effectiveness of denuding epithelium, whilst maintaining the integrity of the BM. RESULTS: EDTA- and dispase-based denuding techniques resulted in the disaggregation and even destruction of the BM structure and molecular composition. Employing thermolysin effectively denuded epithelium whilst maintaining BM structural and molecular integrity. CONCLUSION: Current procedures for preparing AM are variable and often ineffective, resulting in nonstandard membranes. Our novel thermolysin-based technique effectively denudes the AM whilst preserving an essentially intact and consistent BM. Therefore, we propose that this novel thermolysin procedure may potentially improve overall generation of tissue-engineered constructs using AM.

Amniotic membrane for ocular surface reconstruction: donor variations and the effect of handling on TGF-beta content.

PURPOSE: Amniotic membrane (AM) transplantation is an accepted procedure in ocular surgery. However, little is known of the interdonor and intradonor variability within the membrane. In addition, the effects of the methods of processing, storage, and preoperative preparation on the membrane are not fully elucidated. The purpose of this study was to use TGF-beta as an example to investigate interdonor and intradonor variability and to determine the effect of "handling " on TGF-beta1 within fresh, processed and stored, and transplantation-ready AM (TRAM). METHODS: Seventeen human AMs, both fresh and handled, were analyzed for TGF-beta1 by real-time polymerase chain reaction, immunohistochemistry, SDS-PAGE, and Western blotting. RESULTS: TGF-beta1 was the highest normalized expressed isoform of TGF-beta in all samples, but it varied between membranes of different donors and at different sites within the same membrane. The highest concentration was noted in the spongy layer. Removal of the spongy layer successfully removed the bulk of TGF-beta1 from TRAM. Latency-associated protein (LAP) and a latent TGF-beta-binding protein (LTBP) were also detected. CONCLUSION: TGF-beta1 is present in various regulatory forms in the AM. A degree of intermembrane and intramembrane variation is modified by handling. Unless a standardized protocol is adopted that delivers a membrane with consistent constituents, clinical outcomes may vary and comparisons may be invalid.

Do screening-preventative interventions in asymptomatic pregnancies reduce the risk of preterm delivery--a critical appraisal of the literature.

Recent research has suggested that women who experience preterm delivery (PTD) may be identified earlier in pregnancy and before onset of symptoms. Interventions commenced at this earlier asymptomatic stage may offer an opportunity to prevent PTD or lengthen gestation sufficiently to reduce adverse perinatal outcome. Our objective was to examine the evidence that supports or refutes this approach to preventing PTD. We therefore conducted a systematic search and critical appraisal of the identified literature. We found evidence that introducing screening-preventative strategies for asymptomatic pregnancies may reduce the rate of PTD. Evidence for screening and selective treatment exists for: asymptomatic bacteriuria; bacterial vaginosis in low-risk population groups; elective cervical cerclage in high-risk pregnancies; indicated cervical cerclage in women with short cervical length on ultrasound; prophylactic progesterone supplementation in high-risk pregnancies, and smoking cessation. However, for most other strategies, such as increased antenatal attendance, or routine administration of prophylactic micronutrients, the evidence is inconsistent and conflicting. Information on neonatal outcomes apart from PTD (such as serious neonatal morbidity and mortality) was found to be lacking in most studies. It was therefore not possible to establish whether preventing PTD or prolonging gestation would correlate to improved perinatal outcome, and this lessened the potential clinical usefulness of any proposed preventative strategy. No studies were found that evaluated the effectiveness of combining screening-preventative strategies. The review concludes with a suggested an antenatal management plan designed to prevent PTD based on current practice and the evidence presented in this article.

Fetal brain activity and hemodynamic response to a vibroacoustic stimulus.

Previous studies have demonstrated the practicality of using functional magnetic resonance imaging (fMRI) techniques to assess fetal brain activity. The purpose of this study was to compare the fetal hemodynamic response to that of the adult. Seventeen pregnant subjects, all of whom were at more than 36 weeks gestation were scanned while the fetus was exposed to a vibroacoustic stimulus. Thirteen adult subjects were scanned with an equivalent acoustic stimulus. Of the fetal subjects, two could not be analyzed due to technical problems, eight did not show significant activation, and seven showed significant activation. In all cases, activation was localized within the temporal region. Measures of fetal hemodynamic responses revealed an average time to peak (ttp) of 7.36 +/- 0.94 sec and an average percentage change of 2.67 +/- 0.93%. In contrast, activation was detected in 5 of 13 adults with an average ttp of 6.54 +/- 0.54 sec and an average percentage change of 1.02 +/- 0.40%. The measurement of changes in the fetal hemodynamic response may be important in assessing compromised pregnancies.

Presenting and discussing nuchal translucency screening for fetal abnormality in the UK.

OBJECTIVE: to investigate the relationship between information giving by midwives and decision-making by women offered nuchal translucency (NT) screening. To establish how risk figures are discussed in practice, with the intention of relating this to the existing, and often critical, literature on women's accounts of antenatal screening. DESIGN: a qualitative study following women through the process of being offered and deciding to undergo NT screening. Tape recording of consultations, analysed in their entirety, was combined with post-screening interviews. SETTING: a large teaching hospital in the UK. PARTICIPANTS: fourteen pregnant women eligible for NT screening at the time of recruitment. DATA COLLECTION: (i) tape recordings of consultations between community midwives and pregnant women where nuchal translucency screening was offered; (ii) tape recordings of consultations between hospital midwives and pregnant women immediately post-screening; (iii) individual face-to-face interviews with pregnant women between two and six weeks after the screening, carried out by the first author. FINDINGS: NT screening was in general well received, particularly by those women who had undergone serum screening with previous pregnancies. However, communicating the nature of a risk figure is an interactionally complex process. A large amount of interactional work is required by midwives both before and after screening to ensure that women comprehend this information. Despite the emphasis placed in these consultations on understanding the purpose of NT screening and the status of the results, women often framed their decision to undergo NT screening in terms of it being a formality, or of presuming that all was well. This sometimes created practical and personal difficulties in terms of decision-making. KEY CONCLUSIONS AND IMPLICATIONS FOR PRACTICE: previous sociological and psychological research has tended to be critical of midwives in terms of ensuring informed choice in screening, but this research is often based on post hoc accounts. Examining actual consultations with these accounts helps to illustrate the other factors that affect women's perceptions of testing, and the way in which risk, choice and decision-making are introduced and discussed in practice. Encouraging women to consider what action they might take on the basis of a personally unfavourable NT result in advance of undergoing the scan may help them to decide whether the information gained will be useful to them. Recognising the complex interactional work required in making sure that women understand the nature of the results that will be obtained is an important issue for the education and training of midwives.

Fetal brain activity in response to a visual stimulus.

Previous studies have demonstrated the use of functional magnetic resonance imaging (fMRI) to assess fetal brain activity. To extend these studies, a fetal fMRI experiment using a visual stimulus has been performed at 0.5 T. This used a block fMRI paradigm with a bright, constant-intensity light source being shone at the maternal abdomen for 8 sec followed by 16 sec of darkness. This was repeated typically 40 times on nine subjects all of whom were greater than 36 weeks gestational age. Of these, one could not be analysed due to motion, three did not show significant activation, and five showed significant activation (P < 0.0085). In all cases, activation was localised within the frontal cortex. Exact localisation was difficult but this may correspond to the frontal eye fields and dorsolateral prefontal cortex. In no cases was significant activation present within the occipital region as would have been expected and was observed in 2/8 adult subjects. Hum. Brain Mapping 20:239-245, 2003.

Warfarin dosage in postpartum women: a case-control study.

OBJECTIVE: To investigate the clinical suspicion that postpartum women are more difficult to anticoagulate with warfarin than non-pregnant women due to the physiological changes in coagulation proteins that persist into the postpartum period. DESIGN: A retrospective case-control study. SETTING: University Hospital, Nottingham, UK. SAMPLE: Twenty-three postpartum women discharged from the obstetric wards on warfarin and 23 age-matched control women discharged from the medical wards on warfarin were identified using hospital databases. METHODS: Warfarin doses and international normalised ratio values were recorded from day one to 35. The number of days and total warfarin dose to achieve therapeutic international normalised ratio were recorded. Doses were compared with those recommended by a dosing nomogram. RESULTS: The postpartum group took significantly longer and significantly larger doses of warfarin to reach therapeutic international normalised ratio (P < 0.05). The postpartum group required a persistently higher maintenance dose of warfarin. Comparing the warfarin dose given on day three with a standardised nomogram, 79% of women in the postpartum group compared with 57% in the control group were under-dosed. CONCLUSION: Postpartum women require larger doses of warfarin to reach therapeutic international normalised ratio than non-pregnant women. We would recommend the use of a dosing nomogram.