Surfactant Interactions and Solvent Phase Solubility Modulate Small Molecule Release from Emulsion Electrospun Fibers

Emulsion electrospinning provides a tunable system for the development of porous scaffolds for controlled, localized drug delivery in tissue engineering applications. This study aimed to elucidate the role of model drug interactions with emulsion chemistry on loading and release rates from fibers with controlled fiber diameter and fiber volume fraction. Nile Red and Rhodamine B were used as model drugs and encapsulation efficiency and release rates were determined from poly(caprolactone) (PCL) electrospun fibers spun either with no surfactant (Span 80), surfactant, or water-in-oil emulsions. Drug loading efficiency and release rates were modulated by both surfactant and aqueous internal phase in the emulsions as a function of drug molecule hydrophobicity. Overall, these results demonstrate the role of intermolecular interactions and drug phase solubility on the release from emulsion electrospun fibers and highlight the need to independently control these parameters when designing fibers for use as tunable drug delivery systems.

Surfactant location and internal phase volume fraction dictate emulsion electrospun fiber morphology and modulate drug release and cell response

Emulsion electrospinning is a versatile technique used to create fibrous meshes for applications in drug delivery and tissue engineering. In this study, the effects of surfactant and increasing internal phase volume fraction on emulsion electrospun fiber morphology were investigated. The fiber diameter, surface topography, internal architecture, mesh hydrophobicity, and fiber volume fraction were all characterized and the resulting effects on model drug release and cell response were determined. Surfactant relocation to the fiber surface resulted in alterations to fiber surface topography and internal morphology, increased rate of water adsorption into the mesh, and reduced burst effects of drug release. Increasing the internal phase volume fraction within the emulsion resulted in minimal change to fiber diameter, surface morphology, fiber volume fraction, and rate of water adsorption illustrating the ability to increase drug loading without affecting fiber properties. Lastly, all meshes promoted cell adhesion and good viability with a trend of increased MTT absorbance from cells on the surfactant and emulsion fibers possibly suggesting that an increase in surface area via smaller fiber diameter and fiber volume fraction increases metabolic activity. Overall, these studies indicate that fiber morphology and mesh hydrophobicity can be tuned by controlling surfactant location within fibers and internal phase volume fraction. Modulating fiber properties within the emulsion electrospun mesh is important to achieve controlled drug release and cell response for tissue engineering applications.

Real-world impact of laparoscopic surgery for rectal cancer: a population-based analysis

Background

Randomized trials have demonstrated equivalent oncologic outcomes and decreased morbidity in patients with rectal cancer who undergo laparoscopic surgery (lapsx) compared with open surgery (opensx). The objective of the present study was to compare short-term outcomes after lapsx and opensx in a real-world setting.

Methods

A national discharge abstract database was used to identify all patients who underwent rectal cancer resection in Canada (excluding Quebec) from April 2004 through March 2015. Short-term outcomes examined included same-admission mortality and length of stay (los).

Results

Of 28,455 patients, 82.4% underwent opensx, and 17.6%, lapsx. The use of lapsx increased to 34% in 2014 from 5.9% in 2004 (p < 0.0001). Same-admission mortality was lower among patients undergoing lapsx than among those undergoing opensx (1.08% and 1.95% respectively, p < 0.0001). On multivariable analysis, the odds of same-admission mortality with lapsx was 36% lower than that with opensx (odds ratio: 0.64; p = 0.003). Median los was shorter after lapsx than after opensx (5 days and 8 days respectively, p = 0.0001). The strong association of lapsx with shorter los was maintained on multivariable analysis controlling for patient, surgeon, and hospital factors.

Conclusions

For patients with rectal cancer, shorter los and decreased same-admission mortality are associated with the use of lapsx compared with opensx.

Rigid-body motion correction in hybrid PET/MRI using spherical navigator echoes

Integrated positron emission tomography and magnetic resonance imaging (PET/MRI) is an imaging technology that provides complementary anatomical and functional information for medical diagnostics. Both PET and MRI are highly susceptible to motion artifacts due, in part, to long acquisition times. The simultaneous acquisition of the two modalities presents the opportunity to use MRI navigator techniques for motion correction of both PET and MRI data. For this task, we propose spherical navigator echoes (SNAVs)-3D k-space navigators that can accurately and rapidly measure rigid body motion in all six degrees of freedom. SNAVs were incorporated into turbo FLASH (tfl)-a product fast gradient echo sequence-to create the tfl-SNAV pulse sequence. Acquiring in vivo brain images from a healthy volunteer with both sequences first compared the tfl-SNAV and product tfl sequences. It was observed that incorporation of the SNAVs into the image sequence did not have any detrimental impact on the image quality. The SNAV motion correction technique was evaluated using an anthropomorphic brain phantom. Following a stationary reference image where the tfl-SNAV sequence was acquired along with simultaneous list-mode PET, three identical PET/MRI scans were performed where the phantom was moved several times throughout each acquisition. This motion-up to 11° and 14 mm-resulted in motion artifacts in both PET and MR images. Following SNAV motion correction of the MRI and PET list-mode data, artifact reduction was achieved for both the PET and MR images in all three motion trials. The corrected images have improved image quality and are quantitatively more similar to the ground truth reference images.

Ideal hemoglobin transfusion target for resuscitation of massive-transfusion patients

BACKGROUND

Overtransfusion of packed red blood cells is known to increase the risk of death in stable patients. With the delineation of minimum transfusion ratios in hemorrhaging patients complete, attention must be turned to the other end of the massive transfusion spectrum-that of defining the maximum transfusion of packed red blood cells. We aimed to define the ideal hemoglobin range 24 hours after anatomic hemostasis associated with the lowest mortality.

METHODS

Massive-transfusion patients (≥10 units packed red blood cells within 24 hours) were reviewed from 2010-2013. The hemoglobin 24 ± 6 hours after anatomic hemostasis was used to stratify patients into undertransfusion (<8.0 g/dL), hemoglobin transfusion target (8.0-11.9 g/dL), and overtransfusion (>12.0 g/dL) groups; patients not surviving to 24 hours were excluded.

RESULTS

We identified 418 patients (351 [84%] in the hemoglobin transfusion target group, 38 [9%] in the undertransfusion group, and 29 [7%] in the overtransfusion group) with an overall mortality of 18%. Undertransfusion patients had the greatest risk of death (odds ratio 3.3; 95% confidence interval 1.6-6.7) followed by overtransfusion patients (odds ratio 2.5; 95% confidence interval 1.1-5.6). Though pretransfusion hemoglobin was similar (9.5 ± 2.2 g/dL vs 9.5 ± 2.3 g/dL), overtransfusion patients had greater hemoglobin values during massive transfusion (8.3 ± 3.0 g/dL vs 6.9 ± 1.4 g/dL), persisting until hospital dismissal/death (11.4 ± 2.3 g/dL vs 9.6 ± 1.1 g/dL). In total, 657.4 excess packed red blood cell units were transfused (1.9 ± 1.5 per patient).

CONCLUSION

Overtransfusion patients had increased mortality, comparable to undertransfusion patients, despite younger age and fewer comorbidities. Shorter massive transfusion durations foster a scenario in which patients are at greater risk of overtransfusion.

Total Red Blood Cell Transfusions for Chronic Hemodialysis Patients in a Single Center, 2009-2013

BACKGROUND

Anemia management in chronic hemodialysis (HD) has been affected by the implementation of the prospective payment system (PPS) and changes in clinical guidelines. These factors could impact red blood cell (RBC) transfusion in HD patients. Our distinctive care system contains complete records for all RBC transfusions among our HD patients.

AIMS

To determine RBC transfusions in patients with prevalent chronic HD, site of administration (inpatient or outpatient), and ordering physician specialty for inpatients; compare pre- and post-PPS RBC transfusions; and compare RBC transfusions during changes in desired outpatient hemoglobin (Hb) range for patients with chronic HD.

METHODS

Retrospective analysis of medical and blood bank records for patients with prevalent chronic HD July 2009 through June 2013.

RESULTS

In total, 310-356 patients were studied. Mean (SD) units of RBCs per 100 patients per month for the study's 48 months were outpatient, 2.6 (1.5), and inpatient, 9.4 (4.6). Outpatient pre-PPS RBC units transfused were 2.1 (0.6) vs. post-PPS of 2.6 (1.5; p = 0.22, t test); for inpatients pre-PPS, 7.9 (4.5) RBC units per month vs. post-PPS, 11.5 (5.1; p = 0.11, t test). Inpatient RBC transfusions accounted for 75.2% (14.2%) of all RBC transfusions; 67.3% (16.3%) of inpatient transfusions were ordered by nonnephrologists. Changes in desired Hb range for outpatient HD patients did not lead to changes in RBC transfusions.

CONCLUSIONS

No changes in RBC transfusions occurred among our patients with chronic HD with PPS implementation and in desired Hb range during the study period. Most transfusions were given in inpatient settings by nonnephrologists.

Focusing and scanning microscopy with propagating surface plasmons

Here we demonstrate a novel surface plasmon polariton (SPP) microscope which is capable of imaging below the optical diffraction limit. A plasmonic lens, generated through phase-structured illumination, focuses SPPs down to their diffraction limit and scans the focus with steps as small as 10 nm. This plasmonic lens is implemented on a metallic nanostructure consisting of alternating hole array gratings and bare metal arenas. We use subwavelength scattering holes placed within the bare metal arenas to determine the resolution of our microscope. The resolution depends on the size of the scanning SPP focus. This novel technique has the potential for biomedical imaging microscopy, surface biology, and functionalization chemistry.

Computerized bar code-based blood identification systems and near-miss transfusion episodes and transfusion errors

OBJECTIVE

To determine whether the use of a computerized bar code-based blood identification system resulted in a reduction in transfusion errors or near-miss transfusion episodes.

PATIENTS AND METHODS

Our institution instituted a computerized bar code-based blood identification system in October 2006. After institutional review board approval, we performed a retrospective study of transfusion errors from January 1, 2002, through December 31, 2005, and from January 1, 2007, through December 31, 2010.

RESULTS

A total of 388,837 U were transfused during the 2002-2005 period. There were 6 misidentification episodes of a blood product being transfused to the wrong patient during that period (incidence of 1 in 64,806 U or 1.5 per 100,000 transfusions; 95% CI, 0.6-3.3 per 100,000 transfusions). There was 1 reported near-miss transfusion episode (incidence of 0.3 per 100,000 transfusions; 95% CI, <0.1-1.4 per 100,000 transfusions). A total of 304,136 U were transfused during the 2007-2010 period. There was 1 misidentification episode of a blood product transfused to the wrong patient during that period when the blood bag and patient's armband were scanned after starting to transfuse the unit (incidence of 1 in 304,136 U or 0.3 per 100,000 transfusions; 95% CI, <0.1-1.8 per 100,000 transfusions; P=.14). There were 34 reported near-miss transfusion errors (incidence of 11.2 per 100,000 transfusions; 95% CI, 7.7-15.6 per 100,000 transfusions; P<.001).

CONCLUSION

Institution of a computerized bar code-based blood identification system was associated with a large increase in discovered near-miss events.

Optical control of plasmonic Bloch modes on periodic nanostructures

We study and actively control the coherent properties of surface plasmon polaritons (SPPs) optically excited on a nanohole array. Amplitude and phase of the optical excitation are externally controlled via a digital spatial light modulator (SLM) and SPP interference fringe patterns are designed and observed with high contrast. Our interferometric observations reveal SPPs dressed with the Bloch modes of the periodic nanostructure. The momentum associated with these dressed plasmons (DP) is highly dependent on the grating period and fully matches our theoretical predictions. We show that the momentum of DP waves can, in principle, exceed the SPP momentum. Actively controlling DP waves via programmable phase patterns offers the potential for high field confinement applicable in lithography, surface enhanced Raman scattering, and plasmonic structured illumination microscopy.

BMI and attitudes and beliefs about physical activity and nutrition of parents of adolescents with intellectual disabilities

BACKGROUND

The purpose of this study was: (1) to evaluate the beliefs, attitudes and behaviours associated with nutrition and physical activity of parents with adolescents with intellectual disabilities (ID); (2) to determine if these variables related to the body mass index (BMI) of the adolescents and the parents' BMI; and (3) to investigate if the parents' perception of their child's weight status was accurate.

METHODS

A survey was used to collect information on BMI and attitudes and beliefs about nutrition and physical activity from parents (n = 207) of adolescents with ID attending schools participating in the Best Buddies Program.

RESULTS

Approximately 45% of the adolescents were overweight or obese and over two-thirds of the parents were either overweight or obese. There was a significant difference in child's BMI by parents' description, F(3,158) = 72.75, P < 0.001. Factor analysis on questions on physical activity and nutrition revealed three factors (Factor 1 - Family Healthy Habits, Factor 2 - Parental Role and Factor 3 - Parental Activity) extracting 63% of the variance. The BMI of the adolescents significantly correlated with Factors 2 and 3. Children categorised as having a lower BMI had parents who agreed significantly more (r = -0.22, P < 0.005) with questions about being role models. There was a significant correlation between BMI for both the parents and adolescents and frequency of fast foods purchased.

CONCLUSION

Efforts need to be made to provide parents of adolescents with ID tailored information about how they can assist their child in managing their weight. This information should emphasise to parents the important part they play as role models and as providers for healthy choices for physical activity as well as nutrition.

Varying the effective refractive index to measure optical transport in random media

We introduce a new approach for measuring both the effective medium and the transport properties of light propagation in heterogeneous media. Our method utilizes the conceptual equivalence of frequency variation with a change in the effective index of refraction. Experimentally, we measure intensity correlations via spectrally resolved refractive index tuning, controlling the latter via changes in the ambient pressure. Our experimental results perfectly match a generalized transport theory that incorporates the effective medium and predicts a precise value for the diffusion constant. Thus, we directly confirm the applicability of the effective medium concept in strongly scattering materials.

Distribution of heavy-chain variable-region (Vh) subgroups on human lymphocytes

Lymphocytes from 20 normal blood donors were stained with fluorescein isothiocyanate (FITC)-conjugated anti--F(ab')2, anti-VHI, anti-VHII, and anti-VHIII subgroup antisera. The means of the percentages of staining were 2.9%, 5.0% and 5.5% for the VHI, VHII, VHIII subgroups, respectively. The sum of the percentages of the lymphocytes stained with each of the VH subgroup-specific antisera corresponded well with the percentages of lymphocytes stained with an anti-F(ab')2 antiserum. In addition, it was shown by double immunofluorescence staining and in various depletion experiments and tests with thymocytes and lymphocytes from patients with hypogammaglobulinemia that the cells staining with anti-Vh antisera corresponded to the membrane Ig-positive cells--that is, the B-lymphocyte population.

Full characterization of anisotropic diffuse light

We demonstrate a method for fully characterizing diffuse transport of light in a statistically anisotropic opaque material. Our technique provides a simple means of determining all parameters governing anisotropic diffusion. Anisotropy in the diffusion constant, the mean free path, and the extrapolation length are, for the first time, determined independently. These results show that the anisotropic diffusion model is effective for modeling transport in anisotropic samples, providing that the light is allowed to travel several times the transport mean free path from the source.

Toxic effects of mebendazole at high dose on the haematology of red-legged pademelons (Thylogale stigmatica)

OBJECTIVE

To investigate the effects of mebendazole at high dose on the haematology of macropods. Experimental.

PROCEDURE

Five red-legged pademelons (Thylogale stigmatica) were dosed orally with mebendazole at 50 mg/kg/d for 5 to 6 days. Two control pademelons were dosed with water. Regular blood samples were taken for haematology over 20 days.

RESULTS

All four treated pademelons sampled at 5 days developed severe leucopenia and neutropenia, moderate lymphopenia, thrombocytopenia, eosinopenia and monocytopenia, as well as bone marrow aplasia within 5 to 11 days after the first mebendazole dose. Four pademelons died unexpectedly or became ill and were euthanased 5 to 11 days after the first dose while the other animal recovered after 5 days of illness. Necropsy revealed systemic infection with opportunistic enteric bacteria, non-suppurative inflammation in tissues, haemorrhage and ulceration of the gastrointestinal tract.

CONCLUSIONS

Red-legged pademelons rapidly develop bone-marrow aplasia and subsequent septicaemia after administration of high doses of mebendazole. Mebendazole at high doses should not be used for macropods.

Chemical Composition of Inks of Diverse Marine Molluscs Suggests Convergent Chemical Defenses

Some marine molluscs, notably sea hares, cuttlefish, squid, and octopus, release ink when attacked by predators. The sea hare Aplysia californica releases secretions from the ink gland and opaline gland that protect individuals from injury or death from predatory spiny lobsters through a combination of mechanisms that include chemical deterrence, sensory disruption, and phagomimicry. The latter two mechanisms are facilitated by millimolar concentrations of free amino acids (FAA) in sea hare ink and opaline, which stimulate the chemosensory systems of predators, ultimately leading to escape by sea hares. We hypothesize that other inking molluscs use sensory disruption and/or phagomimicry as a chemical defense. To investigate this, we examined concentrations of 21 FAA and ammonium in the defensive secretions of nine species of inking molluscs: three sea hares (Aplysia californica, Aplysia dactylomela, Aplysia juliana) and six cephalopods (cuttlefish: Sepia officinalis; squid: Loligo pealei, Lolliguncula brevis, Dosidicus gigas; octopus: Octopus vulgaris, Octopus bimaculoides). We found millimolar levels of total FAA and ammonium in these secretions, and the FAA in highest concentration were taurine, aspartic acid, glutamic acid, alanine, and lysine. Crustaceans and fish, which are major predators of these molluscs, have specific receptor systems for these FAA. Our chemical analysis supports the hypothesis that inking molluscs have the potential to use sensory disruption and/or phagomimicry as a chemical defense.

The complement regulatory proteins CD55 (decay accelerating factor) and CD59 are expressed on the inner acrosomal membrane of human spermatozoa as well as CD46 (membrane cofactor protein)

The complement regulatory proteins CD55 and CD59 are expressed on the plasma membrane of human spermatozoa, whereas CD46 is only on the inner acrosomal membrane (IAM) which becomes surfaced exposed after the acrosome reaction when sperm assume fertilisation-competence. CD55 & CD59, two glycosylphosphatidylinositol (GPI)-anchored proteins, have been detected previously in some studies also in the acrosomal region of chemically fixed spermatozoa but never demonstrated at this site on unfixed spermatozoa. Dual labelling immunofluorescence and confocal microscopy on fresh unfixed spermatozoa, with minimal subsequent time to fixation, has shown CD55 to be markedly expressed on the IAM, more than on the plasma membrane. However, unlike for CD46, CD55 displayed patchy staining over the acrosome, with some variation between individual spermatozoa. All IAM-associated CD55 was localised within GM1-containing lipid rafts. CD59 was expressed also on the IAM, but in a pronounced granular pattern with more variation observed from one spermatozoa to another. Both CD55 & CD59 were released from the IAM by PI-PLC, demonstrating them to be GPI-anchored. Analysis of acrosome-reacted spermatozoal CD55 by Western blotting revealed a novel single 55 kDa protein lacking significant oligosaccharides susceptible to glycosidases. Antibody-induced membrane rafting and release of CD55 & CD59 in vitro may have influenced previous results. Significant coexpression of CD55 & CD46 on the IAM suggests some functional cooperation at this site.

The association of anti-phospholipid antibodies with parity in placental malaria

Anti-phospholipid antibodies (aPL) are autoantibodies associated with both infections and the pathogenesis of certain pregnancy complications. In the latter, but not the former, aPL are dependent on a co-factor, beta(2) glycoprotein I (beta2GPI), which can also be used as an antigen for detection of such aPL in pregnancy. A cross-sectional study was carried out on serum samples from Kumasi, Ghana, to determine the occurrence and beta2GPI-dependence of aPL in placental malaria. Anti-cardiolipin, anti-phosphatidylserine and anti-beta2GPI enzyme-linked immunosorbent assays (ELISAs) were performed on sera from 103 HIV-non-infected gravid women. Placental malaria, both active and past infection, was diagnosed in 33/103 (32%) based on placental histology. In multiparae, beta2GPI-independent IgM antibodies to cardiolipin (P = 0.018) and phosphatidylserine (P = 0.009) were observed, which were most pronounced in past placental malaria infection. In primiparae, no association emerged between aPL and placental malaria. Trends for improved clinical parameters were identified in infected women with levels of anti-cardiolipin beyond the 99th multiple of the median for a healthy, non-malarious population. This study in placental malaria reports parity associations of beta2GPI-independent aPL profiles, and does not support a role for beta2GPI-dependent aPL. It is of significance in the context of the known parity differences in pregnancy malaria immunity.

First record of quadruplets in the musky ratkangaroo Hypsiprymnodon moschatus

THE musky rat-kangaroo (Hypsiprymnodon moschatus) is endemic to the tropical rainforests of north-east Queensland (Johnson and Strahan 1982). It is the smallest (510 ? 530 g) and most unusual member of the marsupial superfamily Macropodoidea (Dennis and Johnson 1995). Unlike other macropodoids, H. moschatus is frugivorous, diurnal, has an opposable first digit on the pes, a running quadrupedal gait and possesses a relatively unspecialised digestive tract (Johnson and Strahan 1982; Dennis 2002). It also differs from all other macropodoids in typically giving birth to multiple young, usually twins ? although single young and triplets are regularly reported both in the wild and in captivity (Troughton 1967; Johnson and Strahan 1982; Johnson et al. 1983; Dennis and Marsh 1997; Lloyd 2001). However, the birth of more than three young has not previously been observed in H. moschatus or any other macropodoid, even though all species possess four teats.

Introduction of the Proserpine rock-wallaby Petrogale persephone from the Queensland mainland to nearby Hayman Island

Between 1998 and 2002, 27 ‘endangered’ Proserpine rock-wallabies Petrogale persephone were introduced from the Queensland mainland to Hayman Island. Site release selection was based on faunal, botanical, geological and ecological surveys carried out before the release. The eradication of a feral herbivorous competitor, the feral goat (Capra hircus), allowed the introduction to proceed. Eagle predation in the early part of the introduction necessitated all further introductions be carried out by soft release. Between 1999 and 2000, monitoring and non-invasive video surveillance has shown that this introduced population is breeding.

Aberrant cytokine production by peripheral blood mononuclear cells in recurrent pregnancy loss?

BACKGROUND

Successful pregnancy may depend on a Th2-type cytokine response, whilst, conversely, a poor pregnancy outcome may be associated with an increase in Th1 cytokines and a concomitant decrease in Th2 cytokines. This prospective study was designed to elucidate whether a failure of the cytokine shift pre-dated miscarriage and was therefore likely to be an aetiological factor in recurrent pregnancy loss (RPL).

METHODS

Cytokine production by stimulated peripheral blood mononuclear cells from 46 pregnant women who had previously suffered idiopathic RPL during early pregnancy was compared with 25 gestationally age-matched pregnant controls and 11 non-pregnant women.

RESULTS

Production of IFN-gamma was lower in pregnant than in non-pregnant women and even lower in RPL pregnant women (P = 0.0191). IL-10 was increased in pregnant women compared with non-pregnant controls, and further increased in RPL patients (P = 0.026). IL-4 was also increased in women with RPL (P = 0.0001). No differences in IFN-gamma, IL-10 or IL-4 secretion were observed in RPL patients who subsequently miscarried compared with those who successfully completed the pregnancy. RPL women with a successful reproductive outcome had similar concentrations of TNF-alpha to pregnant women, RPL women who subsequently miscarried had significantly lower levels than either pregnant women (P = 0.02) or non-pregnant controls (P = 0.0004).

CONCLUSIONS

Contrary to our hypothesis, the cytokine shift, which appears to characterize normal pregnancy, was accentuated rather than diminished in RPL pregnant women.

Interlayer structures of the chiral smectic liquid crystal phases revealed by resonant X-ray scattering

The structures of the liquid crystalline chiral subphases exhibited by several materials containing either a selenium or sulphur atom have been investigated using a resonant x-ray scattering technique. This technique provides a unique structural probe for the ferroelectric, ferrielectric, antiferroelectric, and SmC(*)(alpha) phases. An analysis of the scattering features allows the structural models of the different subphases to be distinguished, in addition to providing a measurement of the helical pitch. This paper reports resonant scattering features in the antiferroelectric hexatic phase, the three- and four-layer intermediate phases, the antiferroelectric and ferroelectric phases and the SmC(*)(alpha) phase. The helicoidal pitch has been measured from the scattering peaks in the four-layer intermediate phase as well as in the antiferroelectric and ferroelectric phases. In the SmC(*)(alpha) phase, an investigation into the helical structure has revealed a pitch ranging from 5 to 54 layers in different materials. Further, a strong resonant scattering signal has been observed in mixtures of a selenium containing material with as much as 90% nonresonant material.

Development and age estimation of the pouch young of the black-striped wallaby Macropus dorsalis, with notes on reproduction

Macropus dorsalis was capable of breeding throughout the year. The period of gestation was 33 - 36 days. Birth was usually followed by an oestrus and mating, and a subsequent lactation-controlled embryonic diapause. The period between loss of pouch-young and birth was 29 - 30 days. Pouch life was 192 - 225 days and weaning occurred 81 - 159 days after permanent pouch emergence. Sexual maturity, defined as age at first fertility, occurred at 11.3 months in females and 15.7 months in males. Linear mixed-effects models were used to describe polynomial growth equations for age determination of pouch young using both head and pes length. The relationship between error in age prediction and each body measurement was also defined. Head measurements provided the most accurate estimates of the age of pouch young.

Is interleukin-3 important in antiphospholipid antibody-mediated pregnancy failure?

OBJECTIVE

To investigate the effect of interleukin-3 (IL-3) on trophoblast proliferation and expression of beta2-glycoprotein I.

DESIGN

In vitro cell culture using primary trophoblasts and the cell lines Jeg-3, Jar, and BeWo.

SETTING

Department of Obstetrics and Gynaecology, University of Auckland.

PATIENT(S)

Women with normal pregnancies.

INTERVENTION(S)

Increasing amounts of IL-3 were added to cultures of primary human trophoblasts, cell lines, or cells treated with a proliferation inhibiting antiphospholipid-like antibody. RNA was extracted from primary human trophoblasts or cell lines.

MAIN OUTCOME MEASURE(S)

We examined basal and IL-3-stimulated cellular proliferation by [3H] thymidine incorporation assay and secretion of beta2-glycoprotein I into culture medium by semiquantitative immunoblot analysis. Reverse transcriptase-polymerase chain reaction analysis was used to demonstrate the presence of IL-3 receptor transcripts.

RESULT(S)

The IL-3 treatment did not induce proliferation of highly purified primary trophoblast cultures or cell lines but did induce proliferation of contaminating CD45+ cells in trophoblast cultures. The IL-3 did not overcome the antiproliferative effect of an antiphospholipid-like monoclonal antibody on trophoblast. Secretion of beta2-glycoprotein I by trophoblast cultures was time dependent but unaltered by IL-3 treatment.

CONCLUSION(S)

Our results question the proposed importance of IL-3 in antiphospholipid antibody-mediated fetal death.

Age-related radical-induced DNA damage is linked to prostate cancer

We measured concentrations and ratios of mutagenic (8-OH) lesions to putatively nonmutagenic formamidopyrimidine (Fapy) lesions of adenine (Ade) and guanine (Gua) to elucidate radical (.OH)-induced changes in DNA of normal, normal from cancer, and cancer tissues of the prostate. The relationship between the lesions was expressed using the mathematical model log(10)[(8-OH-Ade + 8-OH-Gua)/(FapyAde + FapyGua)]. Logistic regression analysis of the log ratios for DNA of normal and cancer tissues discriminated between the two tissue groups with high sensitivity and specificity. Correlation analysis of log ratios for normal prostates revealed a highly significant increase in the proportion of mutagenic base lesions with age. Data from correlation analysis of the log ratios for normal tissues from cancer were consistent with an age-dependent, dose-response relationship. The slopes for both correlations intersected at approximately 61 years, an age when prostate cancer incidence is known to rise sharply. The age-related increase in the proportion of.OH-induced mutagenic base lesions is likely a significant factor in prostate cancer development.

Resonant x-ray scattering study of the antiferroelectric and ferrielectric phases in liquid crystal devices

Resonant x-ray scattering has been used to investigate the interlayer ordering of the antiferroelectric and ferrielectric smectic C* subphases in a device geometry. The liquid crystalline materials studied contain a selenium atom and the experiments were carried out at the selenium K edge allowing x-ray transmission through glass. The resonant scattering peaks associated with the antiferroelectric phase were observed in two devices containing different materials. It was observed that the electric-field-induced antiferroelectric to ferroelectric transition coincides with the chevron to bookshelf transition in one of the devices. Observation of the splitting of the antiferroelectric resonant peaks as a function of applied field also confirmed that no helical unwinding occurs at fields lower than the chevron to bookshelf threshold. Resonant features associated with the four-layer ferrielectric liquid crystal phase were observed in a device geometry. Monitoring the electric field dependence of these ferrielectric resonant peaks showed that the chevron to bookshelf transition occurs at a lower applied field than the ferrielectric to ferroelectric switching transition.

International profiles of dental hygiene 1987 to 1998: a 19-nation comparative study

AIM

Development of an international longitudinal database to examine patterns, trends and changes in dental hygiene.

METHOD

Three surveys of national dental hygienists' associations, mainly members of the International Federation of Dental Hygienists. Data were collected by mail in 1987, 1992 and 1998, using a 40-item questionnaire. Sample size increased over time; results presented are based on responses for 13, 15 and 19 countries respectively. Preliminary tabulations were circulated to respondents for validation.

RESULTS

Overall, characteristics of the profession were remarkably similar; most noteworthy was the scope of dental hygiene clinical practice. Regarding historical development, education and professional organisation, the profession was more similar than dissimilar. Greater variation was evident in terms of numbers, distribution, workforce behaviour, predominant work setting and remuneration. While apparent change over the relatively short period 1987 to 1998 was viewed with caution, several observations were of particular interest: marked increases in the supply of dental hygienists, scope of practice and range of practice settings, accompanied by a decline in mandated level of work supervision. A slight but gradual increase in independent dental hygiene practice also was noted.

CONCLUSION

By 1998 the profiles reflected the vast majority of the world's population of dental hygienists. While rate of change varied across the countries examined, the nature of the change tended to be consistent, resulting in a continuing homogeneity in the profession worldwide. Changes and emerging trends should continue to be monitored in terms of improved access to quality oral health services and technical efficiency in the provision of those services.

Optical studies of the smectic-C(*)(alpha) phase layer structure in free-standing films

The layer structure of the smectic-C(*)(alpha) phase of one liquid-crystal compound has been acquired from both differential optical reflectivity and ellipsometry measurements in the free-standing film geometry. The data from both techniques display characteristic oscillations as a function of temperature, which can be described by a model for the film consisting of surface anticlinic layers and an interior short-pitched azimuthal helix. These results are consistent with those found previously for another compound. Depolarized reflected light microscopy is used to study the films when the unique features of the aforementioned oscillations occur.

Optical studies of the liquid crystal B2 phase formed by banana-shaped molecules

Null-transmission ellipsometry and depolarized light microscopy have been performed on free-standing films of three achiral banana-shaped compounds in the B2 phase. Our results support a two-layer unit cell previously proposed to explain the observed antiferroelectricity in thin films and bulk samples. We have studied thicker films than previously reported and have found no deviations in the film structure from the earlier findings. Moreover, we can determine the layer spacing, the molecular tilt from the layer normal, and the three principal indices of refraction in the molecular reference frame.

Defensive inking in Aplysia spp: multiple episodes of ink secretion and the adaptive use of a limited chemical resource

The seahare Aplysia spp. extracts many of its defensive chemicals from its red seaweed diet, including its purple ink, which is an effective deterrent against predators such as anemones and crabs. It is believed that the inking behavior is a high-threshold, all-or-none fixed act that nearly completely depletes the seahare of its ink supply. If a seahare depletes its gland of ink, it must seek out a source of red seaweed and then feed for at least 2 days to replenish its ink supply. This suggests that the animal would not be able to deploy ink more than once in rapid succession in response to successive attacks from one or more predators. However, we found that Aplysia spp. can secrete ink in response to three or more successive stimulations with (i) anemone tentacles, (ii) a mechanical stimulus, consisting of grabbing and lifting the animal from the substratum, or (iii) a noxious electric shock. A spectro-photometric measure of ink secretion showed that only approximately 48 % of the gland's releasable ink reserves are deployed initially. Thus, deployment of this defensive chemical is not strictly all-or-nothing, although the trigger mechanism is. Moreover, the animal tends to secrete a relatively fixed proportion (30–50 %) of its available ink reserves even after its gland has been depleted to approximately half its initial content. Since an animal need only use a proportion of its ink reserves to deter an attacker effectively, the inking behavior is adaptive in its economical use of a limited resource.

Thoracoscopic resection of pulmonary nodules after computed tomographic-guided coil labeling

BACKGROUND

A limiting factor in performing video-assisted thoracic surgery for resection of peripheral solitary pulmonary nodules has been the recognition of the lesion visually. This study reports our clinical experience of injecting a small metallic marker under computed tomographic scan guidance before the operation, allowing localization of the lesion.

METHODS

A series of 14 patients underwent video-assisted thoracic surgery for removal of 15 pulmonary nodules situated in the outer third of the lung. Before operation, a radiopaque microcoil was injected just behind the lesion and then used to locate, under fluoroscopy, the area to be resected during thoracoscopy. The technique was evaluated for accuracy, reliability, and ease of use.

RESULTS

Microcoil labeling of peripheral pulmonary nodules allowed in every case a complete resection and a histologic identification of the lesion. It is more stable and accurate than methylene blue dye marking, and it is as easy to perform as computed tomographic scan-guided biopsy. The incidence of complication was small in spite of our inexperience with the technique.

CONCLUSIONS

Our experience with microcoil injection shows that it provides consistent and highly accurate marking of pulmonary nodules for video-assisted thoracic surgery, allowing secure resection with a safe margin.

A Significant Range Extension Of The Purple-Necked Petrogale Purpureicollis Rockwallaby

IN 1982, the Queensland subspecies of the blackfooted rock-wallaby Petrogale lateralis purpureicollis was reported to occur around Mt Isa and south to around Dajarra (Briscoe et al. 1982). During 1991, the known range of this taxon was extended 300 km to the north-west when an adult female P. l. purpureicollis was collected from ?Ridgepole Waterhole? in the Musselbrook Resource Reserve near Lawn Hill National Park (Eldridge et al. 1993). In 1994 the range was further extended when P. l. purpureicollis was recorded from the Constance Ranges and the upper reaches of Stockyard and Elizabeth Creeks; around the town of Cloncurry and the following distances from the town: 85 km north west; 60 and 87 km west; 4, 23, 28 and 35 km south and 15 km east (Bell et al. 1995). Approaches by the Cannington Mining operation to the southwest of McKinley in October 1999 to confirm the presence of rock-wallabies on nearby Glenholme Station established the presence of P. l. purpureicollis; a 75 km range extension to the south-east.

Helminth communities of pademelons, Thylogale stigmatica and T. thetis from eastern Australia and Papua New Guinea

Gastrointestinal helminths were collected from pademelons of the genus Thylogale (Marsupialia: Macropodidae) in eastern Australia and Papua New Guinea. Examined were 12 Thylogale stigmatica stigmatica and 13 T. s. wilcoxi, the latter subdivided into eight specimens from the northern limit of their distribution and five from southern areas, all from eastern Queensland, Australia, one T. s. oriomo from Papua New Guinea and ten T. thetis from southeastern Queensland and northern New South Wales, Australia. Six species of cestodes and 40 species of nematodes were found. The helminth community of T. s. stigmatica was similar to that found in northern specimens of T. s. wilcoxi, while differences from the helminth community present in southern T. s. wilcoxi could be accounted for by parasites acquired from sympatric T. thetis. Thylogale thetis harboured a community of helminths distinct from but related to that in T. stigmatica. The evidence suggests that all subspecies of T. stigmatica examined share a common helminth community, but that in areas of sympatry, T. stigmatica and T. thetis share some of their parasites.

Ellipsometric studies of synclinic and anticlinic arrangements in liquid crystal films

The molecular arrangements in liquid crystal freestanding films are studied when smectic C* surface ordering occurs above the bulk smectic A to smectic C* transition temperature. Details of the resulting structures are resolved using ellipsometry. The behavior of the film is compound dependent. Below a critical electric field, either a synclinic or anticlinic structure may be present depending on the magnitude of the bulk spontaneous polarization. A model is presented in which the low-field anticlinic arrangement results from the interaction between polarization fluctuations at the two surfaces.

Kinetics of layer-thinning transitions in overheated smectic films

The kinetic behavior of dislocation loops in overheated free-standing smectic-A films is reported. The loops open at velocities that are much faster than those seen in nonoverheated films. The velocities increase dramatically as a function of temperature and vary slightly as a function of film thickness. The behavior of dislocation loops induced with a pulsed resistive wire heater is identical to that of the loops giving rise to the layer-thinning transition. In addition, the interaction between two simultaneously nucleated dislocation loops is analyzed. The observed interactions give evidence that thinning occurs in the interior of the film. The results support a model for the layer-by-layer thinning transition based on the nucleation of dislocation loops.

Structure of the liquid-crystal ferrielectric phases as determined by ellipsometry

The unit cell structures of two ferrielectric liquid-crystal phases are determined from ellipsometric studies of freestanding films in a nondistorting rotatable electric field. A highly biaxial mode with out-of-plane distortions describes all of the data from two different compounds. Qualitative and quantitative features of the data rule out alternate models. We also present a detailed explanation for apparent inconsistencies between previous resonant x-ray and optical experiments.

Leucocyte populations and cytokine regulation in human uteroplacental tissues

Human endometrial tissue and the decidualized endometrium in pregnancy contain relatively large numbers of leucocytes, the proportions of which vary during both the menstrual cycle and early pregnancy. CD3+ T-cells, CD14+ macrophages and a population of phenotypically unusual CD3-CD16-CD56++ large granular lymphocytes (LGL) are present, whereas B-cells are virtually absent. Relative T-cell numbers decrease in first-trimester decidua; T-cells are therefore unlikely to have an important role in the immunological maintenance of pregnancy but could be more important in implantation, when their relative numbers are greater. Extensive numbers of class II MHC-positive tissue macrophages in both the endometrium and placenta will provide an immediate antigen non-specific host defence to infection at this important site. Nevertheless, most attention has focused on a role for the predominant LGL endometrial cell population in the implantation and maintenance of pregnancy because, at the time of implantation, these LGLs comprise 70-80% of all leucocytes in the endometrium. It is now well recognized that there is substantial and complex cytokine activity within human uteroplacental tissues; both leucocytic and non-leucocytic cells have been shown to be capable of producing a significant array of cytokines. However, to avoid excessive pathological sequelae, such cytokine activity must be locally regulated. This has been highlighted by recent reports indicating that abnormal Th1-type cytokine responses could be a reason for immunological reproductive failure in women. Key cytokines controlling differentiation into a Thl (interleukin 12) or Th2 (interleukin 4) type pattern both exist in unusual molecular forms at the human maternal-fetal tissue interface and hence might be fundamental regulatory elements controlling cytokine action locally by an antagonistic action.

Immunological aspects of implantation and implantation failure

The human endometrium contains a significant proportion of leukocytes (8-35% of all cells), the absolute numbers and proportions varying during both the menstrual cycle and early in pregnancy. T cells, macrophages and a population of phenotypically unusual large granular lymphocytes (LGL) are commonly present, although B cells are absent. Relative T cell numbers decrease significantly in first trimester decidua, and hence are unlikely to play an important role in maintenance of human pregnancy, but T cells could be important in implantation where their relative numbers are greater. In addition to producing cytokines, local tissue macrophages may provide an immediate antigen non-specific host defence to infection. Most attention has, nevertheless, focused on a role for LGL in implantation and maintenance of pregnancy since, at the time of implantation, LGL comprise 70-80% of the total endometrial leukocyte population. Although endometrial LGL have been shown to express natural killer (NK) cell-type cytotoxicity against classical NK cell targets, such cytotoxicity against trophoblast is induced only after activation by interleukin (IL)-2. Selective expression of the unusual class I human leukocyte antigen (HLA) molecule, HLA-G, by extravillous cytotrophoblast may assist in protecting invasive cytotrophoblast from potential maternal NK cell attack, probably via interactions with killer inhibitory receptor molecules on LGL. Many cytokines have been demonstrated to be expressed at the maternal-fetal interface although, currently, in mice only two (IL-11 and leukaemia inhibitory factor) appear to be absolutely essential for successful pregnancy outcome. Immune effector cells and cytokines may also play a role in human pregnancy pathologies, such as recurrent early pregnancy loss.

Pre-implantation endometrial leukocytes in women with recurrent miscarriage

Immunohistochemistry was used to investigate the leukocyte populations in the endometrium of women suffering recurrent miscarriage. Mid-luteal phase endometrial biopsies were taken from 22 patients with idiopathic recurrent miscarriage and from nine women with normal obstetric histories. The samples were dated histologically and stained with a panel of monoclonal antibodies to identify leukocytes. The outcome of any pregnancy in subsequent cycles following the biopsy was determined. Similar numbers of cluster designation (CD)3(+) and CD8(+) cells were seen in both groups. However, CD4(+), CD14(+), CD16(+), CD56(+) and MHC class II(+) cells were significantly higher in the recurrent miscarriage group than in the controls. Two patients had B cells (CD22(+)) in their endometrium. No CD57(+) cells were seen in the controls; however, eight of the patients had a few CD57(+) cells present. Only two patients, both from the recurrent miscarriage group, had CD69(+) leukocytes in their endometrium. Patients who had miscarriages following endometrial biopsy had significantly more CD4(+), CD8(+), CD14(+), CD16(+), and CD56(+) leukocytes in their endometrium than either those who had live births or women with proven fertility. A different population of leukocytes was found in the pre-implantation endometrium from recurrent miscarriage patients as compared to those from fertile controls. These differences were accentuated in women who had a miscarriage subsequent to the biopsy compared with those who subsequently had a live birth.

Thinning transitions in free-standing liquid-crystal films as the successive formation of dislocation loops

We describe a model for the layer-thinning transition in free-standing liquid-crystal films based on the successive, spontaneous formation of dislocation loops. As the film temperature increases and the smectic order and layer compressional modulus decrease, the condition for creating a dislocation loop of critical radius is met and a thinning is nucleated. The resulting equation for N, the number of smectic layers, as a function of temperature yields good fitting results to the thinning transitions obtained from several fluorinated compounds.