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OBJECTIVE: To describe the presenting signs, concurrent conditions, treatment and outcome of dogs with metaphyseal osteopathy.MATERIALS AND METHODS: Multi-centre retrospective review of medical records from January 2009 to September 2018 at four referral centres to identify dogs with a radiographic diagnosis of metaphyseal osteopathy.RESULTS: Thirty-nine dogs were identified. The median age at onset was 14 weeks old (range, 8 to 32 weeks old). There was a higher proportion of male dogs (29 of 39 male entire, nine of 39 female entire, one of 39 female neutered and no male neutered dogs). Where information was available, median time from the most recent vaccination was 20 days (range, 2 to 144 days). The most commonly recorded clinical signs were pyrexia (34 of 39), lethargy (32 of 39), pain (30 of 39), and being non-ambulatory (17 of 39). Thirty-five dogs required hospitalisation for analgesia and supportive care, 19 of 39 were discharged on prednisolone (median dose 2.0 mg/kg/day; range, 0.9 to 2.6 mg/kg/day), 18 of 39 were discharged on non-steroidal anti-inflammatories, two of 39 did not receive NSAIDs or prednisolone at any time point. The median duration of hospitalisation for those admitted was 5 days (range, 1 to 21 days). Where follow-up was available, relapse occurred in eight of 25 cases before reaching skeletal maturity. At the time of metaphyseal osteopathy diagnosis, five of 39 cases had concurrent conditions. Where follow-up was available, four of 25 developed future immune-mediated conditions.CLINICAL SIGNIFICANCE: Metaphyseal osteopathy should be considered in non-ambulatory painful young dogs. Some dogs developed future immune-mediated conditions, which may support the hypothesis that metaphyseal osteopathy is an autoinflammatory bone disorder. Further studies with a larger cohort are required to determine the clinical significance of this.

This study validates a novel mentorability scale, or, a survey measuring first-year college students’ ability to be mentorable. The scale was developed after two pilot studies across three years and was administered in Fall 2019 to 84 first-year students at a large, Hispanic-serving institution in the U.S. South. The scale includes items on how mentees perceive their own ability to be open to feedback, commit time to their mentor, use their mentor’s advice, attend meetings and co-curricular events with their mentor, discussion social lives and academics with their mentor, listen to their mentor, and be respectful of their mentor. Initial results suggest that students who rated themselves highly as being willing to take advice from their mentor correlated with semester-to-semester and year-to-year retention. Implications for first-year student retention and postsecondary mentoring programs will be addressed.

PurposeThe purpose of this paper is to explore how postsecondary mentoring programs address mentee dispositions prior to the mentee entering the reciprocal relationship, particularly which mentee dispositions are valued across mentoring program types, including peer, community-to-student, faculty-to-student and faculty-to-faculty programs.Design/methodology/approachThis study employed quantitative content analysis to examine 280 institutional US postsecondary mentoring websites across four different institution types (public, four-year; private, four-year, non-profit; private, four-year, for-profit; public, two-year) and four different mentoring program types (peer or student-to-student, community-to-student, faculty-to-student and faculty-to-faculty programs). Grounded coding strategies were employed to generate these four mentoring program types, supported by extant research (Crispet al., 2017).FindingsOf 280 mentoring programs, 18.6 percent articulated mentee dispositions prior to entering the reciprocal relationship. When mentoring programs did address mentees, most programs articulated mentor duties aligned with mentee expectations (47.5 percent of programs) and program outcomes for mentees (65.7 percent of programs) rather than what the mentee can and should bring into a reciprocal relationship.Research limitations/implicationsThis study is delimited by its sample size and its focus on institutional website content. Future studies should explore how mentoring programs recruit and retain mentees, as well as how website communications address the predispositions and fit of mentees within different types of mentoring programs.Practical implicationsThis study provided evidence that many postsecondary mentoring programs in the USA may not be articulating programmatic expectations of mentees prior to the mentoring relationship. By failing to address mentee predispositions, mentoring programs may not be accurately assessing their mentor’s compatibility with their mentees, potentially leading to unproductive mentoring relationships.Originality/valueThis study affirms extant research (Black and Taylor, 2017) while connecting mentor- and coaching-focused literature to the discussion of a mentee dispositions scale or measurement akin to Crisp’s (2009) College Student Mentoring Scale and Searby’s (2014) mentoring mindset framework. This study also forwards an exploratory model of mentoring program inputs and outputs, envisioning both mentor and mentee characteristics as fundamental inputs for a mentoring program rather than traditional models that view mentors as inputs and mentee achievements as outputs (Crisp, 2009; Searby, 2014).

Although researchers support the notion that college- and university-sponsored mentoring programs effectively academically transition and retain postsecondary students from a variety of sociocultur...

Objectives To describe the presentation, influence of previous treatment and diagnosis in juvenile dogs presenting with pyrexia to a UK referral centre. Materials and Methods Clinical records of dogs aged 1 to 18 months presenting with a problem list including pyrexia (≥⃒39∙2°C) that was reproducible during referral hospitalisation were retrospectively reviewed. Signalment, history ‐ including previous treatment, clinical examination findings and diagnosis were recorded. Diagnoses were categorised as non‐infectious inflammatory, infectious, congenital, neoplastic and miscellaneous. The influence of previous treatment on the ability to reach a final diagnosis was analysed. Results A total of 140 cases was identified. Diagnosis was reached in 115 cases. Non‐infectious inflammatory disease was identified in 91 cases (79%), infectious disease in 19 cases (17%), a congenital disorder in four dogs (3%) and neoplasia in one dog (1%). Breeds most commonly identified were Border collies (17/140; 12%), beagles (16/140; 11%), Labrador retrievers (11/140; 8%), springer spaniels (9/140; 6%) and cocker spaniels (8/140; 6%). Before presentation, most dogs had received antibiotics (83/140; 59%), non‐steroidal anti‐inflammatory drugs (84/140; 60%) or steroids (9/140; 6%), either alone or in combination. Neither antibiotics nor non‐steroidal anti‐inflammatory drugs influenced the ability to reach a diagnosis. Steroid‐responsive meningitis‐arteritis comprised 55 of 91 (60%) individuals of the non‐infectious inflammatory cohort. All four dogs diagnosed with congenital disorders were Border collies. Clinical significance Non‐infectious inflammatory disease, particularly steroid‐responsive meningitis‐arteritis, immune‐mediated polyarthritis and metaphyseal osteopathy, was commonly diagnosed in this population of pyrexic juvenile dogs.

Summary Human natural killer (NK) cells play an important role in anti-viral immunity. However, studying their activation kinetics during infection is highly problematic. A clinical trial of a therapeutic virus provided an opportunity to study human NK cell activation in vivo in a controlled manner. Ten colorectal cancer patients with liver metastases received between one and five doses of oncolytic reovirus prior to surgical resection of their tumour. NK cell surface expression of the interferon-inducible molecules CD69 and tetherin peaked 24–48 h post-infection, coincident with a peak of interferon-induced gene expression. The interferon response and NK cell activation were transient, declining by 96 h post-infection. Furthermore, neither NK cell activation nor the interferon response were sustained in patients undergoing multiple rounds of virus treatment. These results show that reovirus modulates human NK cell activity in vivo and suggest that this may contribute to any therapeutic effect of this oncolytic virus. Detection of a single, transient peak of activation, despite multiple treatment rounds, has implications for the design of reovirus-based therapy. Furthermore, our results suggest the existence of a post-infection refractory period when the interferon response and NK cell activation are blunted. This refractory period has been observed previously in animal models and may underlie the enhanced susceptibility to secondary infections that is seen following viral infection.

It is well established that exposure to ozone (O 3 ) may impair vegetative growth and reproductive development in plants, although the consequences for yield depend on the effectiveness of the compensatory processes induced. This study examined the effects of exposing the terminal inflorescence of Brassica campestris L. to 100 ppb O 3 for 6 h d −1 on four consecutive days during early flowering while the vegetative organs received charcoal-filtered air. The ordered predictability of development in B. campestris is ideal for studies of the impact of abiotic stress factors such as O 3 on reproductive development and seed production. Effects on reproductive development and seed yield characteristics were determined for floral sites exposed at different developmental stages. Flower and pod numbers on the terminal raceme were unaffected by exposure, but effects on pod length varied depending on the developmental stage of floral sites during exposure. Increased ovule abortion and precocious seed germination in the pods of O 3 -treated plants reduced mature seed number pod −1 . Although the individual weight of mature seeds was slightly greater in O 3 -treated plants, seed yield pod −1 and seed yield plant −1 were reduced due to the lower seed number pod −1 . Seed from O 3 -treated plants germinated more rapidly than control seed irrespective of the stage of floral development during exposure. The results show that exposure to realistic O 3 episodes during the early stages of flowering significantly reduced seed yield without impairing the vigour of the seeds produced. The physiological origins of these effects are discussed.

Exposure to ozone (O 3 ) affects both vegetative and reproductive growth in plants, although consequences for seed yield depend on the efficacy of compensatory reproductive processes. This study examined whether the limited compensatory capacity of species with determinate reproductive strategies influences seed production following exposure. The first flowering spike (Spike 1) of Plantago major L. populations which exhibit contrasting sensitivity of vegetative growth to chronic O 3 exposure was exposed, while the leaves and second spike (Spike 2) received charcoal-filtered air. Exposure of Spike 1 during flowering influenced seed number capsule −1 on both spikes, even though Spike 2 was not exposed. Responses varied between populations, position on the spike and plant age at the start of exposure; the greater impact on capsules located on the upper section of the spike suggests they were more responsive. Compensatory increases in seed number capsule −1 in the middle and upper sections of Spikes 1 and 2 generally precluded significant effects on seed number spike −1 ; individual seed weight was largely unaffected. However, the combined seed weight of Spikes 1 and 2 was increased by 19% in the two O 3 -resistant populations following exposure to 120 ppb O 3 on 9 successive days, suggesting that they over-compensated for injury, but was reduced by 21% in the most sensitive population. Compensatory reproductive responses and their possible implications for biomass production, biodiversity and carbon sequestration in natural communities in temperate regions are discussed.

Apoptosis leads to the fragmentation and packaging of cellular contents into discrete vesicles, a process known as 'blebbing'. Extracellular vesicles express membrane-bound sialic acids, which enable their capture by CD169 (sialoadhesin; Siglec-1) expressing macrophages in the lymph node and spleen. Furthermore, CD169 mediates vesicle trafficking and suppresses the immune response to exosomes-a type of extracellular vesicle released from living cells. In this study, we found that CD169(+) macrophages were the predominant splenic macrophage subset responsible for the capture of EL4 lymphoma-derived apoptotic vesicles (ApoVs) from circulation. CD169(-/-) mice had significantly enhanced in vivo cytotoxic T lymphocyte responses to antigen-pulsed ApoVs, indicating a suppressive role for CD169(+) macrophages to ApoV-associated antigen. In contrast to the observed immunogenic role of ApoVs, the co-administration of unpulsed ApoVs with antigen-pulsed dendritic cells (DCs) significantly suppressed DC-mediated cytotoxic response in vivo; however, this occurred independent of CD169 expression. Overall, our results confirm that apoptosis contributes to both tolerance and immunity, as well as establishing CD169 as a critical mediator of the immune response to extracellular vesicles.

Interactions between natural killer (NK) cells and dendritic cells (DCs) aid DC maturation and promote T-cell responses. Here, we have analyzed the response of human NK cells to tumor cells, and we identify a pathway by which NK-DC interactions occur. Gene expression profiling of tumor-responsive NK cells identified the very rapid induction of TNF superfamily member 14 [TNFSF14; also known as homologous to lymphotoxins, exhibits inducible expression, and competes with HSV glycoprotein D for HVEM, a receptor expressed by T lymphocytes (LIGHT)], a cytokine implicated in the enhancement of antitumor responses. TNFSF14 protein expression was induced by three primary mechanisms of NK cell activation, namely, via the engagement of CD16, by the synergistic activity of multiple target cell-sensing NK-cell activation receptors, and by the cytokines IL-2 and IL-15. For antitumor responses, TNFSF14 was preferentially produced by the licensed NK-cell population, defined by the expression of inhibitory receptors specific for self-MHC class I molecules. In contrast, IL-2 and IL-15 treatment induced TNFSF14 production by both licensed and unlicensed NK cells, reflecting the ability of proinflammatory conditions to override the licensing mechanism. Importantly, both tumor- and cytokine-activated NK cells induced DC maturation in a TNFSF14-dependent manner. The coupling of TNFSF14 production to tumor-sensing NK-cell activation receptors links the tumor immune surveillance function of NK cells to DC maturation and adaptive immunity. Furthermore, regulation by NK cell licensing helps to safeguard against TNFSF14 production in response to healthy tissues.

Summary 421 I. INTRODUCTION 421 II. EFFECTS OF OZONE ON REPRODUCTION 423 1. Pollen germination and pollen tube growth 424 2. Floral initiation and development 428 3. Effects on seed and fruit yield and yield components 433 4. Effects of ozone on seed and fruit quality, germination and seedling growth 437 III. INFLUENCE OF REPRODUCTIVE HABIT AND IMPLICATIONS FOR FIELD-GROWN PLANTS 438 IV. CONCLUSIONS AND FUTURE RESEARCH 441 Acknowledgements 442 References 442 Sexual reproductive development is a crucial stage in the life cycle of higher plants as any impairment of the processes involved might have significant implications for the productivity of crop plants and the survival of native species. There is considerable evidence that exposure to ozone, even at current ambient levels in many industrialized countries, reduces grain and fruit yields and adversely affects yield quality. It is also well established that sensitivity to ozone may differ not only between species, but also between cultivars and populations of individual species, and that the impact of exposure is highly dependent on ozone concentration and the duration and timing of exposure. However, few studies have attempted to distinguish between the direct effects of air pollutants on reproductive development, and indirect effects mediated by injury to the vegetative organs and associated changes in the supply of assimilates and other essential resources to support reproductive growth, or the levels of endogenous growth regulators. This review considers the impact of ozone on the reproductive biology of agricultural and native species, and examines its direct effects on specific reproductive processes. The extent to which compensatory responses redress the adverse effects of exposure is also explored, with particular reference to recent studies of Brassica napus (oilseed rape), Brassica campestris (Wisconsin Fast Plants), Plantago major (greater plantain) and Triticum aestivum (wheat).

Adrenal androgen (AA) excess, primarily in the form of dehydroepiandrosterone sulfate (DHEAS), affects over 50% of women with the polycystic ovary syndrome (PCOS). Nonetheless, it is unclear what role AA excess plays in the PCOS-associated oligo-ovulation. We have hypothesized that AAs are important in the maintenance of the ovulatory dysfunction of women with PCOS and AA excess, which can be improved by glucocorticoid suppression. To test our hypothesis we prospectively studied 36 unselected women, ages 18-40 yr, with PCOS; i.e. oligomenorrhea (cycles > 35 days in length), and clinical/ biochemical evidence of hyperandrogenism (i.e. hirsutism and/or hyperandrogenemia), after the exclusion of related disorders. After informed consent, all patients underwent an acute ACTH-(1-24) stimulation test, measuring androstenedione, dehydroepiandrosterone (DHEA) and cortisol (F), and were then treated with dexamethasone 0.5 mg/day for four cycles. Ovulatory function was assessed before and during treatment using a basal body temperature calendar and day 22-24 progesterone (P4) levels. If patients were anovulatory (P4 4 ng/mL); and of the remaining, 10 (28%) had only one, five (14%) had two, and three (8%) had three ovulatory cycles. There were no significant differences either in physical features, basal hormones, adrenal response to ACTH stimulation, or hormonal levels at the end of treatment, between those women ovulating and those not. Finally, there were no differences in ovulatory response to dexamethasone therapy between women with (n = 14) and without (n = 22) DHEAS excess (i.e. DHEAS > 2750 ng/mL). In conclusion, the data from this prospective study do not suggest that continuous dexamethasone suppression results in consistent ovulation in any PCOS patient, regardless of basal DHEAS levels. Furthermore, this treatment is associated with significant side-effects, notably weight gain. Finally, these data suggest that, while AA may be an important risk factor for PCOS, once the syndrome is established, they play a limited role in the associated ovulatory dysfunction.

Over 50% of patients with the polycystic ovary syndrome (PCOS) demonstrate excess levels of adrenal androgens (AAs), particularly dehydroepiandrosterone sulfate (DHS). Nonetheless, the mechanism for the AA excess remains unclear. It has been noted that in PCOS the pituitary and ovarian responses to their respective trophic factors (i.e. GnRH and LH, respectively) are exaggerated. Similarly, we have postulated that excess AAs in PCOS arises from dysfunction of the hypothalamic-pituitary-adrenal axis, due to 1) exaggerated pituitary secretion of ACTH in response to hypothalamic CRH, 2) excess sensitivity/responsivity of AAs to ACTH stimulation, or 3) both. To test this hypothesis we studied 12 PCOS patients with AA excess (HI-DHS; DHS, >8.1 μmol/L or 3000 ng/mL), 12 PCOS patients without AA excess (LO-DHS; DHS

Summary The effects of a single 6-h exposure of the inflorescences of Brassica napus cvs. Libravo and Tapidor to 100 nL L −1 ozone on seed yield, yield parameters, seed quality and seedling vigour were examined using purpose-designed chambers that enabled the inflorescences to be exposed separately from the vegetative organs. Exposure of cv. Libravo significantly reduced seed number per plant, seed weight per pod and per plant, 1000 seed weight, the oil, protein and soluble carbohydrate contents of the seed and seedling vigour. In contrast, no significant effects of exposure were observed at final harvest in cv. Tapidor, largely because increases in the numbers and dry weight of seed enabled the plants to compensate for significant initial losses of reproductive sites induced by pollutant exposure. The importance of varietal differences in compensatory flexibility in response to pollutant-induced losses of reproductive sites and the implications of the observed effects on seed quantity and quality for field-grown plants are discussed.

Summary A novel controlled environment system was constructed to allow the reproductive structures of small annual plants to be exposed to gaseous atmospheric pollutants independently of the vegetative component. The design and experimental application of this system, which permits up to 12 plants to be exposed simultaneously, are described. A single exposure of flowering racemes of Brassica campestris L. to 100 nL L -1 ozone for 6 h had no significant effect on the numbers of reproductive sites produced or aborted. This contrasts sharply with the related species, B. napus L., in which a single exposure to 100 nLL -1 ozone induced significant losses of reproductive sites. However, multiple exposures of B. campestris to ozone produced significant effects on seed abortion and mature seed number per pod at final harvest, the extent of which depended on the developmental stage of the reproductive organ at the time of exposure. Despite these effects, seed number per plant, mean seed weight and total seed weight per plant at maturity were not significantly affected, indicating a high degree of compensation during reproductive development. The origins and ecological significance of these responses are discussed.

SUMMARY The flowering racemes of Brassica napus L. cv. Tapidor were exposed independently from the vegetative component to 200 nl l−1, 100 nl l−1 O3/30 nl l−1 SO2, In all cases, a single 6 h exposure significantly increased bud abortion, and abscission 2 and 5 d after treatment. Similar results were obtained using cv. Libravo, although the effect of 100 nl l−1 O3 was significant only after 2 d. Exposure to 30 nl l−1 SO2 did not enhance bud abortion and abscission in either variety. Longer term measurements for up to 25 d revealed a trend to wards sustained losses of fertile sites in those pollutant treatments which had exhibited demonstrable, effects after 2 and/or 5 d. However, the number of fertile sites present was comparable to or even higher than in the controls, indicating that compensation for the initial losses must have occurred. Following exposure, plants of cv. Tapidor tended to develop longer total raceme lengths and greater numbers of raceme branches, and those of cv. Libravo a greater number of raceme branches. Indicating possible methods by which new fertile sites may have been produced. The significance of these observations for the reproductive development of field-grown oilseed rape is discussed.

SUMMARY A single exposure of pollen of Brassica napus L. cvs Tapidor or Libravo to 100 nl l−1 ozone (O3) either in vitro or in vivo on the anthers of intact plants had no significant effect on either pollen germination or pollen tube growth. Exposure of dry pollen to 200 nl l−1 sulphur dioxide (SO2) also produced no significant effect. However, pollen germination was significantly reduced and pollen tube growth impaired in both cultivars when pollen was exposed in unbuffered incubation medium to 200 nl l−1 SO2. The pH of the unbuffered medium fell from 6.5 to 5.5 during fumigation, suggesting a role for acidification in the observed SO2-induced effects. This view is supported by evidence that percentage germination decreased linearly with pH in culture media buffered to provide pH values ranging from 6.05 to 3.0. Pollen tube growth was also impaired at pHs of 5.6 and below. The significance of pollutant-induced impairment of pollen germination and growth for reproductive development and the influence of moisture in modifying the impact of SO2 and O3 are discussed.

Exposure to ozone (O(3)) may affect vegetative and reproductive development, although the consequences for yield depend on the effectiveness of the compensatory processes induced. This study examined the impact on reproductive development of exposing Brassica campestris (Wisconsin Fast Plants) to ozone during vegetative growth. Plants were exposed to 70 ppb ozone for 2 d during late vegetative growth or 10 d spanning most of the vegetative phase. Effects on gas exchange, vegetative growth, reproductive development and seed yield were determined. Impacts on gas exchange and foliar injury were related to pre-exposure stomatal conductance. Exposure for 2 d had no effect on growth or reproductive characteristics, whereas 10-d exposure reduced vegetative growth and reproductive site number on the terminal raceme. Mature seed number and weight per pod and per plant were unaffected because seed abortion was reduced. The observation that mature seed yield per plant was unaffected by exposure during the vegetative phase, despite adverse effects on physiological, vegetative and reproductive processes, shows that indeterminate species such as B. campestris possess sufficient compensatory flexibility to avoid reductions in seed production.

1. Denitrification in floodplain soils is one of the main biological processes emitting and reducing nitrous oxide, a greenhouse gas, and the main process responsible for the buffering capacity of riparian zones against diffuse nitrate pollution. 2. The aim of this study was to measure denitrification rates under a wide range of current climatic conditions and hydrological regimes in Europe (from latitude 64°N to latitude 42°N and from longitude 2°W to longitude 25°E), in order to determine the response patterns of this microbial process under different climatic and hydrological conditions, and to identify denitrification proxies robust enough to be used at the European scale. 3. Denitrification activity was significant in all the floodplain soils studied whatever the latitude. However, we found an increase in rates of an order of magnitude from high to mid latitudes. Maximum rates (above 30 g N m?2 month?1) were measured in the maritime conditions of the Trent floodplain. These rates are similar to mineralisation rates measured in alluvial soils and of the same order of magnitude as the amount of N stored in herbaceous plants in alluvial soils. 4. We used Multivariate Adaptative Regression Splines to relate the response variable denitrification with five relevant predictors, namely soil moisture, temperature, silt plus clay, nitrate content and herbaceous plant biomass. 5. Soil moisture, temperature, and nitrate were the three main control variables of microbial denitrification in alluvial soils in decreasing order of importance. 6. The model developed for denitrification with interaction effects outperformed a pure additive model. Soil moisture was involved in all interactions, emphasising its importance in predicting denitrification. 7. These results are discussed in the context of scenarios for future change in European hydrological regimes.

Twenty term/near term neonates with hypoxemic respiratory failure and oxygenation index >/=20 were enrolled in a Phase I/II feasibility, safety and dose escalation study of inhaled PGE(1) (IPGE(1)). Incremental doses of IPGE(1), delivered by a jet nebulizer over a 2-h period, followed by weaning over 1 h, were given to 13 patients before receiving inhaled nitric oxide (INO) (Group I), and to seven patients, who failed to respond to INO (Group II). Response was defined as an increase in P(a)O(2) of either >/= 25 (full) or 10-25 (partial) torr. Exit criteria included an acute deterioration in oxygenation status, a persistent oxygenation index above 35 in Group I, or the availability of extracorporeal membrane oxygenation (ECMO) in Group II. The mean (SD) increase in P(a)O(2) at the end of IPGE(1) administration was 63 (62.3) in Group I (p = 0.024), and 40 (62.1) in Group II (p > 0.05). In Group I, 8 of 13 neonates had a full response, but 4 deteriorated following discontinuation of IPGE(1). Of these four, two responded to INO and two were placed on ECMO. Five patients deteriorated before or during IPGE(1,) and none of them responded to INO. In Group II, three of seven patients had a full response to IPGE(1). One patient with a partial response and all patients exiting before or during IPGE(1) administration were placed on ECMO. The results of our study indicate that IPGE(1) may be a safe, selective pulmonary vasodilator in neonatal hypoxemic respiratory failure.

It was hypothesized that prenatal exposure to cocaine and other substances would be related to delayed expressive language development. Speech and language data were available for 458 6-year olds (204 were exposed to cocaine). No significant univariate or multivariate differences by cocaine exposure group were observed. Classification and regression tree modeling was then used to identify language variable composites predictive of cocaine exposure status. Meaningful cut points for two language measures were identified and validated. Children with a type token ratio of less than 0.42 and with fewer than 97 word types were classified into a low language group. Low language children (n = 57) were more likely to be cocaine exposed (63.1%), with cocaine-exposed children 2.4 times more likely to be in the low language group compared with control children after adjustment for covariates. Prenatal cigarette, but not alcohol exposure, was also significantly related to expressive language delays.

Continuous fiber ceramic composites (CFCCs) are being considered as high temperature structural materials for gas turbine applications due to their high temperature capability, toughness, and durability. Polymer impregnation and pyrolysis (PIP) derived CFCCs are one class of these materials that can be fabricated using widely available polymer composite processing methods. This paper will discuss the general PIP fabrication process and thermo-mechanical properties of these materials, and show examples of complex prototype gas turbine components that have been fabricated and evaluated.Copyright © 1999 by ASME

Adrenal androgen (AA) excess, primarily in the form of dehydroepiandrosterone sulfate (DHEAS), affects over 50% of women with the polycystic ovary syndrome (PCOS). Nonetheless, it is unclear what role AA excess plays in the PCOS-associated oligo-ovulation. We have hypothesized that AAs are important in the maintenance of the ovulatory dysfunction of women with PCOS and AA excess, which can be improved by glucocorticoid suppression. To test our hypothesis we prospectively studied 36 unselected women, ages 18-40 yr, with PCOS; i.e. oligomenorrhea (cycles35 days in length), and clinical/ biochemical evidence of hyperandrogenism (i.e. hirsutism and/or hyperandrogenemia), after the exclusion of related disorders. After informed consent, all patients underwent an acute ACTH-(1-24) stimulation test, measuring androstenedione, dehydroepiandrosterone (DHEA) and cortisol (F), and were then treated with dexamethasone 0.5 mg/day for four cycles. Ovulatory function was assessed before and during treatment using a basal body temperature calendar and day 22-24 progesterone (P4) levels. If patients were anovulatory (P44 ng/mL), a withdrawal bleed was induced by the administration of 100 mg P4 in oil i.m. Before and during treatment the levels of total and free testosterone (T), sex hormone-binding globulin, androstenedione, DHEA, DHEAS, cortisol, luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were monitored. With therapy, all patients demonstrated a significant decrease in all androgens (-40-60%), a 24% increase in sex hormone-binding globulin, and no change in LH/FSH. Mean body weight increased by over 4 kg (4.4%) during treatment. Of the 138 cycles monitored, 78% remained anovulatory. Twenty-five percent, 17%, 14%, and 20% of the first, second, third, and fourth treatment cycles, were ovulatory, respectively (P = 0.381). Of the 36 patients studied, 18 (50%) did not demonstrate a single ovulatory cycle (i.e. a day 22-24 P4 level4 ng/mL); and of the remaining, 10 (28%) had only one, five (14%) had two, and three (8%) had three ovulatory cycles. There were no significant differences either in physical features, basal hormones, adrenal response to ACTH stimulation, or hormonal levels at the end of treatment, between those women ovulating and those not. Finally, there were no differences in ovulatory response to dexamethasone therapy between women with (n = 14) and without (n = 22) DHEAS excess (i.e. DHEAS2750 ng/mL). In conclusion, the data from this prospective study do not suggest that continuous dexamethasone suppression results in consistent ovulation in any PCOS patient, regardless of basal DHEAS levels. Furthermore, this treatment is associated with significant side-effects, notably weight gain. Finally, these data suggest that, while AA may be an important risk factor for PCOS, once the syndrome is established, they play a limited role in the associated ovulatory dysfunction.

In utero passage of meconium may represent a response to hypoxic stress or a normal maturational event. When found during the third trimester, one may be tempted to use its presence as prima facie evidence of fetal lung maturity. The purpose of our study was to determine the frequency of meconium-stained fluid in the third trimester and the incidence of biochemical and physiologic lung immaturity in these fetuses.Amniotic fluid specimens obtained at our institution from 1991 through 1993 (n = 2,377) were analyzed for maturity and visually inspected for meconium. Perinatal outcome was obtained for intramural deliveries occurring within 3 days of amniotic fluid collection (n = 905). Gestational age was defined as the best obstetric estimate based on menstrual dates, clinical examination, and ultrasound results.Meconium staining was present in 2.7% (n = 64) of specimens. Although meconium-stained specimens were more likely to have mature lecithin-sphingomyelin (L:S) ratios (OR 2.1, 95% confidence interval [CI] = 1.2-3.6) and phosphatidylglycerol (PG) concentrations (OR 3.8, CI 2.2-6.7), 17.2% were immature for both L:S and PG (n = 11, CI = 9.9-28.2%). When analysis was limited to fetuses delivering intramurally within 3 days of amniotic fluid collection, respiratory distress syndrome occurred in 3.0% (CI = 0.5-15%) with meconium-stained fluid.The presence of meconium in amniotic fluid does not guarantee lung maturity. The same consideration of the risks of prematurity must be given to the fetus with meconium-stained fluid as given to the fetus with clear fluid.

To determine whether gestational age is a significant determinant of neonatal outcome, irrespective of biochemical lung maturity. The effects of specimen source and clarity on the reliability of biochemical tests for predicting respiratory distress syndrome are also evaluated.Perinatal outcome was analyzed for 904 neonates undergoing amniotic fluid maturity studies within three days of delivery from 1991 to 1993. The relationships of gestational age and biochemical maturity to neonatal outcome were examined using multivariate analysis of covariance. Test reliability was evaluated using log-linear analysis of multiway frequency tables.Gestational age was a better predictor of neonatal outcome than biochemical lung maturity. Gestational age significantly correlated with every measure of outcome except intraventricular hemorrhage and jaundice. Test reliability was not significantly influenced by specimen source or clarity.Results obtained using contaminated amniotic fluid are reliable when the proper technique is used. Irrespective of biochemical maturity, neonatal outcome is significantly related to gestational age. Gestational age, and not just biochemical maturity, should be considered when timing delivery.

To determine the incidence and site of single photon emission computed tomography scan (SPECT) abnormalities in survivors of neonatal extracorporeal membrane oxygenation and to evaluate the efficacy of SPECT scan as a predictor of neurodevelopmental outcome in these infants.Tertiary care neonatal intensive care unit in Detroit, MI.Survivors of neonatal extracorporeal membrane oxygenation who had a SPECT scan of the brain performed after decannulation and before their discharge from the neonatal intensive care unit were included if they had at least 12 months of follow-up in our developmental assessment clinic.The neurological outcome was reported as normal, suspect, and abnormal on the basis of neurological examination and developmental milestones. The developmental outcome was assessed by Bayley mental development index or McCarthy general cognitive index scores.A total of 59 patients met study criteria. SPECT scan abnormalities were noted in 45 (76%) infants. Global hypoperfusion was the most frequent abnormality followed closely by bilateral focal perfusion defects. The distribution of perfusion abnormalities was not significantly different for right and left hemispheres. Among 14 infants with normal SPECT scans, 13 infants had normal neurological outcome and all had a normal developmental outcome. Of the 45 infants with an abnormal SPECT scan, 7 infants had an abnormal neurological outcomes and 4 infants had an abnormal developmental outcome. SPECT scan abnormalities had no significant correlation with neurodevelopmental outcome of these infants.Although a normal SPECT scan was more likely to predict a normal neurodevelopmental outcome, an abnormal SPECT scan did not predict an abnormal outcome in these infants.

Concerns about global warming and the role of rising atmospheric carbon dioxide (CO2) content seem to have relegated studies of the effects of air pollutants to a position of secondary importance. There are very strong arguments for a continuing high profile for research on the impacts of nitrogenous air pollutants (NOx, NH3), ozone (O3) and non-methane hydrocarbons (NMHCs). Atmospheric concentrations of these pollutants are increasing steadily and it is highly probable that they will continue to do so. Furthermore, these changes in atmospheric composition will be accompanied by increasing levels of UV-B radiation.

Ozone is a gaseous pollutant of major agricultural significance in many countries, inducing changes in plant growth and altering patterns of resource allocation, water use efficiency and development in a number of crop species. Much of the evidence for these detrimental effects comes from the US NCLAN programme, in which crop plants were exposed to a range of ozone concentrations throughout the growing season. Ambient concentrations of ozone were found to be sufficiently high to cause adverse effects in 13 of the 14 species studied. However, these data cannot be used directly to assess pollutant-induced crop losses in Britain and other european countries because firstly the crops, cultivars and cultivation regimes employed differ between the two continents and secondly climatic factors such as temperature and rainfall, which are known to influence plant responses to pollutants, may also differ markedly. For example, crops in northern europe frequently complete their initial growth in winter when cold or waterlogging stress may be prevalent and concentrations of pollutants such as SO2 are at their highest. In contrast to many areas of the USA, crops in Europe are rarely exposed to regimes of single pollutants, but more commonly to simultaneous or sequential exposure to several gaseous pollutants including ozone, sulphur dioxide and oxides of nitrogen. The presence of these additional pollutants may be an important determinant of plant responses to pollutant regimes in Europe. Since 1985, a European open top chamber network has examined the effects of gaseous pollutants on temperate arable crops. This chapter reviews existing knowledge of the influence of ozone on temperate arable crops, and considers its interactions with other environmental stresses including sulphur dioxide. It also attempts to identify whether sufficient information exists to permit: 1) quantification of the impact of current concentrations of ozone alone and in combination with other pollutants on arable crops in the UK and; 2) prediction of plant responses to changes in the environmental and pollution regimes induced by global climate change.

Brefeldin A (BFA) has previously been shown to block protein transport from the endoplasmic reticulum (ER), to cause the redistribution of Golgi components to the ER, and to change profoundly the morphology of the Golgi apparatus. In order to quantitate the effects of this drug on the morphology of the ER and the Golgi apparatus in HeLa cells, the numerical, surface and volume densities of these organelles were determined by stereological means. We found that in cells treated with BFA (5 micrograms/ml) clusters of vesicles and tubules, often located near transitional elements of the ER, replaced the Golgi apparatus. The numerical density of these clusters in cells treated with BFA for 30 min or 4.5 h is similar to that of Golgi complexes and Golgi-related clusters in control cells. The surface density of the vesicles and tubules contained in these clusters is about 50% of that represented by Golgi elements in control cells. Concomitantly, a corresponding increase in the surface density of the ER-Golgi hybrid compartment was observed. This hybrid compartment contained Golgi-specific enzymes effecting modifications of N-linked oligosaccharides and the transfer of O-linked sugars. Antibodies recognizing different subcompartments of the Golgi apparatus or the intermediate compartment, labeled vesicles and tubules of the Golgi-related clusters. Applying low doses of BFA allowed for the dissection of the disassembly of the Golgi apparatus into at least two phases. At very low doses (10-20 ng/ml) the numerical density of vesicles in the clusters increased up to 4-fold above control, while the surface density did not markedly change, suggesting that vesiculation of the Golgi cisternae had occurred. Fusion of Golgi elements with the ER seemed to occur only at doses of BFA higher than 20 ng/ml. Contrary to observations on other cell types, removal of BFA from HeLa cell cultures resulted in a rather slow reformation (1-2 h) of the Golgi complex, which allowed us to observe several intermediate stages in this process. During this time period an ER was restored which no longer contained Golgi-specific O-glycosylation functions. Our results demonstrate that BFA does not simply cause the disappearance of the Golgi apparatus by fusion with the ER, but instead clusters of vesicles and tubules remain that contain Golgi-specific markers.

Adrenal androgen (AA) excess, primarily in the form of dehydroepiandrosterone sulfate (DHEAS), affects over 50% of women with the polycystic ovary syndrome (PCOS). Nonetheless, it is unclear what role AA excess plays in the PCOS-associated oligo-ovulation. We have hypothesized that AAs are important in the maintenance of the ovulatory dysfunction of women with PCOS and AA excess, which can be improved by glucocorticoid suppression. To test our hypothesis we prospectively studied 36 unselected women, ages 18-40 yr, with PCOS; i.e. oligomenorrhea (cycles > 35 days in length), and clinical/ biochemical evidence of hyperandrogenism (i.e. hirsutism and/or hyperandrogenemia), after the exclusion of related disorders. After informed consent, all patients underwent an acute ACTH-(1-24) stimulation test, measuring androstenedione, dehydroepiandrosterone (DHEA) and cortisol (F), and were then treated with dexamethasone 0.5 mg/day for four cycles. Ovulatory function was assessed before and during treatment using a basal body temperature calendar and day 22-24 progesterone (P4) levels. If patients were anovulatory (P4 4 ng/mL); and of the remaining, 10 (28%) had only one, five (14%) had two, and three (8%) had three ovulatory cycles. There were no significant differences either in physical features, basal hormones, adrenal response to ACTH stimulation, or hormonal levels at the end of treatment, between those women ovulating and those not. Finally, there were no differences in ovulatory response to dexamethasone therapy between women with (n = 14) and without (n = 22) DHEAS excess (i.e. DHEAS > 2750 ng/mL). In conclusion, the data from this prospective study do not suggest that continuous dexamethasone suppression results in consistent ovulation in any PCOS patient, regardless of basal DHEAS levels. Furthermore, this treatment is associated with significant side-effects, notably weight gain. Finally, these data suggest that, while AA may be an important risk factor for PCOS, once the syndrome is established, they play a limited role in the associated ovulatory dysfunction.

Background: Exposure to violence in childhood has been associated with lower school grades. However, the association between violence exposure and performance on standardized tests (such as IQ or academic achievement) in children is unknown. It is also not known whether violence exposure itself or subsequent symptoms of trauma are primarily responsible for negative outcomes. Objective: To examine the relationship between violence exposure and trauma-related distress and standardized test performance among early school-aged urban children, controlling for important potential confounders. Design: A total of 299 urban first-grade children and their caregivers were evaluated using self-report, interview, and standardized tests. Main Outcome Measures: The child’s IQ (Wechsler Preschool and Primary Scale of Intelligence–Revised) and reading ability (Test of Early Reading Ability, second edition) were the outcomes of interest. Results: After controlling for confounders (child’s gender, caregiver’s IQ, home environment, socioeconomic status, and prenatal exposure to substance abuse) violence exposure was related to the child’s IQ (P=.01) and reading ability (P=.045). Trauma-related distress accounted for additional variance in reading ability (P=.01). Using the derived regression equation to estimate effect sizes, a child experiencing both violence exposure and trauma-related distress at or above the 90th percentile would be expected to have a 7.5-point (SD, 0.5) decrement in IQ and a 9.8point (SD, 0.66) decrement in reading achievement. Conclusion: In this study, exposure to violence and trauma-related distress in young children were associated with substantial decrements in IQ and reading achievement.

This paper reports a quick, relatively simple and reproducible technique for obtaining populations of zona fasciculata and zona glomerulosa cells up to 80-90% pure, which can be maintained in vitro for study of adrenocortical cell function. Isolated guinea pig adrenocortical cells were separated on a 1-28% bovine serum albumin/Ca++, Mg++-free buffer gradient (wt/vol at 4% increments) using equilibrium density centrifugation (570 g, 30 min). Over 60% of the 8 x 10(5) viable cells/adrenal obtained in the total isolate were recovered after separation. 80% of the zona glomerulosa cells were found in the lower three bands of the gradient. 78% of the zona fasciculata cells were found in the top three bands. Of the cells in the first two bands, 78-91% were zona fasciculata cells, whereas of the cells in the bottom two bands 92-95% were zona glomerulosa cells. The cells retained the morphological characteristics of cells in situ and could be maintained in vitro for periods up to 11 d. They produced a wide variety of steroids, cortisol, corticosterone, aldosterone, 11-beta-hydroxyandrostenedione, deoxycortisol, deoxycorticosterone, cortisone, 18-hydroxycorticosterone, and a product tentatively identified as dehydroepiandrosterone, and they responded to ACTH in a dose-responsive manner with enhanced levels of steroid output. Zona glomerulosa-enriched populations differed from zona fasciculata-enriched populations in their abundant production of aldosterone and in the pattern of steroid production. None of the cultures responded to angiotensin II (100 pg/ml) with increased steroid production.

Exposure to low concentration of SO2 increases stomatal conductance in field bean by c 20%. Microscopy of epidermal strips showed that this response was associated with extensive destruction of epidermal cells adjacent to the stomata. Guard cell survival was not affected signficantly. Collapsed epidermal cells were also observed in intact leaf samples using scanning electron miscroscopy, thus confirming that the damage seen in epidermal strips was not caused by the stripping procedure. These observations are discussed in relation to the hypothesis that the increased stomatal opening induced by low SO2 concentrations results from preferential injury to the adjacent cells.

Stomatal conductances (gj of plants of Vicia faba, Raphanus sativus, Phaseolus vulgaris, Helianthus annuus, and Nicotiana tabacum were measured in chambers containing either clean air or air containing between 18 and 1000 parts 10~9 S02 at water vapour pressure deficits (vpd) ranging from 1 -0 to 1 • 8 kPa. When vpd was low ( 1 part 10~6) may close stomata (Bonte, de Cormis, and Louguet, 1977; Caput, Belot, Auclair, and Decourt, 1978; Kondo and Sugahara, 1978). Environmental variables such as sulphur supply to the soil and atmospheric humidity can also influence stomatal responses to S02. Cowling and Lockyer (1976) reported a reduction in the coefficient of transpiration in ryegrass plants exposed to 17-5 parts 10~9 S02 for 198 d when the supply of soil sulphur was inadequate, but no difference was observed between water use of polluted and unpolluted plants if soil sulphur was not limiting. Mansfield and Majernik (1970) found that stomatal apertures of Vicia faba increased following exposure to 0-25-1 part 10~6 S02 at relative humidities above 40% but decreased when humidity was below 40% at 18 °C. These varied reports demonstrate that stomatal response to S02 are complex and must be studied in well-defined environments. Because such responses influence rates of transpiration and C02 exchange and modify the absorption rates of S02 at metabolic sites within the leaf, they have important implications for growth, development, and yield of crop plants. The objectives of this investigation were therefore (i) to monitor continuously the responses of stomata in plants exposed to filtered air or air containing a range of S02 concentrations greater than 17-5 parts 10~9 (50 pg rrr3) throughout several photoperiods and (ii) to study the influence of atmospheric humidity on stomatal responses to S02. METHODS Plants were grown in pots in compost containing adequate sulphur in growth rooms and well watered. Three-week old plants, with pots sealed in polythene bags to prevent water loss, were transferred to two exposure chambers in which environmental conditions were comparable to those in the growth room (189 W m~2 and 22 ± 0-5 °C day and 16 ± 0-5 °C night temperatures). The plants were then left to acclimatize in charcoal-filtered air (< 2 parts 10~9 S02) for one photoperiod before making measurements or imposing an experimental treatment. The following day, both chambers were again supplied with clean air and continuous measurements of transpiration rates and stomatal conductances were made on both sets of plants using a sensitive monitoring system and methods of analysis described previously (Black and Unsworth, 1979). Since stomata are extremely sensitive to small changes in environmental conditions the temperature, humidity, and air movements of both exposure chambers was precisely controlled. On the third day, when stomata were fully open, a known concentration of S02 was introduced into one chamber and the responses of polluted and control plants were monitored while water vapour pressure deficit (vpd) (defined here as the difference bel ween saturation vapour pressure at mean leaf temperature and the vapour pressure in the chamber) was varied from 1-0 to 1-8 kPa. Temperature and irradiance were kept constant. In a separate series of experiments, Vicia faba L. (cv. Dylan) plants were fumigated with S02 for several hours in the dark when stomata were closed or when they had been prevented from closing by exposure to low C02 concentrations (50 parts 10-6 C02). The stomatal conductance of these plants was monitored using a water vapour infrared gas analyser in the dark period before introduction of S02, during exposure to S02 concentrations which ranged from 17-5 to 1000 parts 10~9, and in the subsequent light and dark periods following removal of the pollutant. Checks on the accuracy of stomatal conductance values calculated from infrared gas analysis measurements were made using a diffusion porometer (Delta-T Devices Mark II). Agreement between the two sets of conductance values was extremely good (Black and Black, 1979). Both these methods estimate leaf conductance and not stomatal conductances. However since leaf This content downloaded from 207.46.13.15 on Fri, 26 Aug 2016 05:36:03 UTC All use subject to http://about.jstor.org/terms Black and Unsworth—S tomatal Responses to S02 669 conductance was small (0-02 cm s ') when plants were in the dark, stomatal conductances were assumed to be equal to the measured and calculated values of leaf conductance. RESULTS In the results to be described, although each experiment was repeated at least four times it is not always appropriate to describe the change in stomatal conductance by a mean value and standard error since stomatal aperture is influenced by a variety of factors including plant age, plant water status, time of day, etc. Therefore Figs 1 and 2a demonstrate the typical responses of single sets of plants exposed to either filtered or polluted air whereas Fig. 2b describes the results of duplicate experiments on different sets of plants. Figures 3 and 4 show the data obtained from at least four different sets of plants. Figure 1 shows the stomatal conductance of V.faba plants exposed to filtered air and air containing 17-5 and 87-5 parts 10~9 (200 pg m~3 and 1000 jug m~3) S02 '2 when vapour pressure deficit was 1-3 kPa at 22 °C. The figure demonstrates the typical 20-30% increase in conductance induced by exposure to S02 in the light. Exposure to higher concentrations (up to 350 parts 10~9) resulted in the same proportional increase in conductance irrespective of S02 concentration. In the dark, stomatal conductances of polluted plants were considerably larger than those of control plants. Consistent with differences in stomatal responses, treated plants transpired faster than controls. Figure 1 also shows that stomata responded within 15 min after addition of Lights on Lights off Lights on Lights off Lights on Lights off I \ so2 I I I J 0.9

Apparatus is described for exposing plants to low concentrations of S02 (50-500/jg m~3 in air) and for measuring effects on photosynthesis, dark respiration, and transpiration. Temperature, humidity, and irradiance in the chambers were controlled independently, and fans ensured that leaf boundary layer resistances were low. Experiments with plants of Vicia faba in clean and polluted air showed that: (i) a depression of net photosynthesis by 50 /ug m~3 S02 depended on boundary layer resistance and on irradiance; (ii) stomatal resistance was increased or decreased by 50 iug nr3 S02 when relative humidity in the chambers was low (35% r.h., 22 °C) or high (50% r.h., 22 °C) respectively.

1. By asphyxiating goldfish in sealed bottles of water containing dissolved carbon dioxide and oxygen, it was found that the ability of the fish to use oxygen in the presence of carbon dioxide increases as the acclimation temperature of the fish is raised.2. Goldfish acclimated at 1° C. are limited in their ability to use oxygen when a tension of 60 mm. or more carbon dioxide is present in the water, whereas goldfish acclimated at 32° C. are not limited in the utilization of oxygen unless the carbon dioxide tension is 200 mm. or more. Fish at intermediate temperatures of 7°, 15° 20° and 25° C. begin to show a decrease in the ability to use oxygen when they are in the presence of carbon dioxide tensions of 100, 120, 140, and 170 mm. respectively.3. Reliable results could be obtained only after complete acclimation of the fish to the temperature at which the experiments were made. However, with acclimated fish of similar stock the result could be reproduced from year to year at the same season.4. The explan...

DNA polymerases alpha and delta from rabbit bone marrow were purified to specific activities greater than 30 000 nM TMP incorporated (mg of protein)(-1)h(-1). alpha is quantitatively predominant. alpha and delta have the same reaction requirements and are both similarly sensitive to N-ethylmaleimide. The primary functional distinction is the association of 3' to 5' exonuclease activity with delta. Sedimentation coefficients obtained from zone sedimentation in glycerol gradients and Stokes radii values from gel filtration allow the calculation of true molecular weight and frictional ratios. alpha exhibits a bimodal pattern, sedimenting at 6 and 8 S on glycerol gradients and demonstrating components corresponding to 40.5- and 65-A Stokes radii upon gel filtration. The calculated molecular weights of the two forms of alpha are 100 000 and 215 000; the frictional ratios are 1.34 and 1.65. This and other data suggest a possible monomer-dimer relation. In contrast, delta sediments uniformly at 6.5 S and also behaves uniformly upon gel filtration at 4595 A. The molecular weight of delta is distinct at 122 000; its frictional ratio is 1.39. Because of similarities of the DNA polymerizing activities of both forms of alpha and of delta, it is postulated that alpha is derived from delta by structural modification, resulting in a decrease in molecular weight, the tendency to aggregate as dimers, and a concomitant loss of 3' to 5' exonuclease activity.

The use of partial plasma exchange transfusion in newborns with polycythemia and hyperviscosity was evaluated. Ninety-three infants with polycythemia and hyperviscosity were randomly assigned to receive either partial plasma exchange transfusion or symptomatic treatment; the infants were matched with control infants without polycythemia. Neonatal course and outcome at 1 and 2 years were evaluated for each of the three groups. Polycythemic infants had more fine motor and speech problems at 1 year of age than did control infants. At 2 years of age, polycythemic infants had more gross motor delays, neurologic diagnoses, fine motor abnormalities, and speech delays than did the control infants. There was no significant difference at 1 year between the polycythemic infants who had received partial plasma exchange transfusion and those given only symptomatic care. At 2 years, the group receiving partial plasma exchange transfusion had fewer neurologic diagnoses and fine motor abnormalities.

Necrotizing enterocolitis is uncommon among term infants. In this group, necrotizing enterocolitis has been associated with two risk factors: polycythemia and umbilical catheterization. During a randomized trial of partial plasma exchange transfusion for treatment of polycythemia, an increased risk of gastrointestinal problems was noted. Eight hyperviscous patients treated with partial plasma exchange transfusion, no symptomatically treated patients, and no control infants developed typical necrotizing enterocolitis (blood in the stools, pneumatosis, and systemic signs). The incidence of necrotizing enterocolitis was significantly greater among patients treated with exchange transfusion compared with patients treated symptomatically or control subjects (P less than .001).