The spectrum of onset of acute kidney injury in premature infants less than 30 weeks gestation.

OBJECTIVE: To determine risk factors for acute kidney injury (AKI) in preterm infants as a function of time of onset. STUDY DESIGN: In this 5 1/2-year, single-center, retrospective study, incidence and timing of AKI was determined using modified Acute Kidney Injury Network criteria. Characteristics of newborns with and without AKI were compared by chi square and t-tests. Logistic regression was used to examine risk factors for AKI as a function of time of onset and potential confounders. RESULT: AKI occurred in 30.3% of 357 neonates; 72.2% was stage 1. Gestational ages (GA), initial Cr, maternal magnesium and volume resuscitation were associated with early AKI (days 0 to 1). Volume resuscitation, umbilical arterial line and receipt of non-steroidal anti-inflammatory drug (NSAID) for patent ductus arteriosus were associated with intermediate AKI (days 2 to 5). GA, steroids for early hypotension, necrotizing enterocolitis and sepsis were associated with late AKI (⩾day 6). CONCLUSION: Stage 1 AKI is a common morbidity in our population. Risk factors for AKI in our population differed with time of onset.

Relationship of maternal creatinine to first neonatal creatinine in infants <30 weeks gestation.

OBJECTIVE: To examine the relationship between maternal and neonatal creatinine (Cr) in preterm infants in the context of antenatal and intrapartum maternal and neonatal factors. STUDY DESIGN: In this 5½-year, single-center, retrospective study, paired maternal and neonatal Cr were compared by t-test. Linear regression for correlated outcomes employing generalized estimating equations was used to examine neonatal Cr as a function of antenatal maternal Cr and potential confounders. RESULT: A total of 157 neonates of 124 mothers met study criteria. Neonatal Cr values in the first 24 h of life were significantly higher than antenatal maternal values. Linear regression modeling showed that maternal Cr, neonatal lactate, hypoxic-ischemic villous changes on placental pathology and multiple gestation were each significant determinants of the first neonatal Cr. CONCLUSION: No neonatal Cr was less than its paired maternal value. Maternal Cr, neonatal lactate, hypoxic-ischemic villous changes in the placenta and multiple gestation were each significantly associated with neonatal Cr.

Impact of renal function and protein intake on blood urea nitrogen in preterm infants in the first 3 weeks of life.

OBJECTIVE: To examine the relationship between blood urea nitrogen (BUN) during the first 3 weeks of life and protein intake and creatinine (Cr) and to quantify the effect of protein intake on postnatal growth in preterm infants. STUDY DESIGN: This is a 4-year, single-center, retrospective cohort study. We used multivariable linear regression models to examine the relationships between mean weekly BUN and protein intake adjusted for mean weekly Cr and potential confounders. We used additional regression models to examine the effect of protein intake on growth during this period. RESULT: Overall, 249 infants met study criteria. As protein intake increased over the first 3 weeks of life, both BUN and Cr decreased significantly. Linear regression models showed protein intake and Cr were each significantly associated with mean BUN for each study week. CONCLUSION: Protein intake and Cr were each significantly associated with BUN. Significant amelioration of growth failure was seen with higher protein intake.

Ovulation induction and small for gestational age neonates in twin pregnancies.

OBJECTIVE: To compare the incidence of small for gestation age (SGA) neonates in twin gestations conceived by ovulation induction or in vitro fertilization with that of twins conceived spontaneously. STUDY DESIGN: A retrospective cohort study was conducted. Subjects were delivered by a single obstetric practice between 2005 and 2011 at the Mount Sinai Medical Center. Maternal and neonatal data were recorded. Our primary outcome was the incidence of SGA, defined as birth weight <10th percentile, from the three modes of conception. Chi square, ANOVA, Fisher's exact test, the Kruskal-Wallis test, the Mantel-Haenszel test, and logistic regression were used in the analysis. RESULTS: In unadjusted analysis, using the records of 756 infants from 378 mothers of twin pregnancies, twins conceived by ovulation induction had an increased incidence of SGA (28.1%) compared to those conceived spontaneously (17.1%) and by in vitro fertilization (16.5%, p = 0.006). In a logistic regression model accounting for correlated responses between twins and adjusting for gestational age, gender, chorionicity, and maternal age, the odds ratio (95% confidence interval [CI]) of SGA for the ovulation induction group compared to the spontaneous conception group was 2.64 (1.38-5.05, p = 0.003). The odds ratio (95% CI) of SGA for the in vitro fertilization group compared to the spontaneous conception group was 1.51 (0.88-2.61, p = 0.135). CONCLUSIONS: When adjusted for gestational age, gender, chorionicity, and maternal age, twin neonates conceived by ovulation induction, but not those conceived by in vitro fertilization, had increased odds of SGA compared to those conceived spontaneously.

Rescue corticosteroids in twin pregnancies and short-term neonatal outcomes.

OBJECTIVE: To estimate the efficacy of a rescue course of antenatal corticosteroids in twin pregnancies. DESIGN: Retrospective cohort study. SETTING: Tertiary-care centre. POPULATION: Twins born from 24 to <34 weeks of gestation in a single maternal and fetal medicine practice from 2006 to 2011. METHODS: We compared neonatal outcomes in 88 twins exposed to a single course of corticosteroids with outcomes in 42 twins exposed to two courses of corticosteroids: the initial course and a single rescue course. Analyses were adjusted to control for correlation between twins born to the same mother. MAIN OUTCOME MEASURE: Short-term neonatal respiratory morbidity. RESULTS: Rescue corticosteroids were associated with fewer days of mechanical ventilation (7.3 ± 3.3 versus 33.9 ± 25.3 days, P = 0.003), fewer days with a fraction of inspired oxygen of >21% (6.3 ± 4.3 versus 33.3 ± 25.8 days, P = 0.003), a lower incidence of mechanical ventilation >14 days or death while on mechanical ventilation (0 versus 12.5%, P = 0.016), and a lower incidence of retinopathy of prematurity (0 versus 12.5%, P = 0.016). The proportion of neonates with respiratory distress syndrome did not differ between the groups (adjusted odds ratio 1.28, 95% confidence interval 0.50-3.26). There were no differences found for birthweight, head circumference and length. CONCLUSIONS: In twins born before 34 weeks of gestation, exposure to rescue corticosteroids may be associated with improved neonatal outcomes. Further studies are warranted to assess the effect of rescue corticosteroids in twin pregnancies.

Antenatal antibiotic exposure in preterm infants with necrotizing enterocolitis.

OBJECTIVE: To determine whether an association exists between antenatal antibiotic exposure and incidence of necrotizing enterocolitis (NEC) in low birth weight infants. STUDY DESIGN: A retrospective case-control study was performed on all infants with a diagnosis of NEC born at our institition between 1988 and 2006. Medical histories of all infants with a diagnosis of NEC ≥Bell's stage IIA and matched controls without NEC were reviewed. Maternal and neonatal characteristics were compared using the Mantel-Haenszel chi-square procedure, and logistic regression models were constructed to account for confounding. RESULT: Clinical data for 97 matched pairs were analyzed. The adjusted odds ratio (OR) for antenatal exposure to ampicillin was significantly greater for infants who developed NEC (OR 2.3, 95% confidence interval 1.1, 4.8, P=0.003) than for control infants. CONCLUSION: Infants who developed NEC were more likely to have a history of in utero exposure to ampicillin in the immediate antepartum period than infants who did not develop NEC.

Serological survey of Toxoplasma gondii and Campylobacter fetus fetus in sheep from New Zealand.

AIM: To determine the prevalence of antibody titres to Toxoplasma gondii and Campylobacter fetus fetus in sheep from New Zealand. METHODS: As part of a free screening service, unsolicited blood samples were supplied by veterinarians wishing to gauge the exposure of their clients' ewe flocks to T. gondii and C. fetus fetus. Blood samples were submitted from mixed-age ewes throughout New Zealand, from 2006 to 2009, that had not been vaccinated for T. gondii and C. fetus fetus. A total of 2,254 sera were serologically titrated for T. gondii and 3,429 for C. fetus fetus. A latex agglutination kit available commercially was used to quantify antibodies to T. gondii, and an agglutination test developed in-house was used for C. fetus fetus. For T. gondii, titres of ≥1:16 and ≥1:64 were used to define a positive response, and for C. fetus fetus a titre of ≥1:10 was defined as positive. A flock was defined as positive if ≥1 ewe had a positive titre. RESULTS: Of the sera tested for T. gondii, 1,917/2,254 (85%) were positive, using a titre of ≥1:16, and 1,384/2,254 (61%) with a titre of ≥1:64. All 198 ewe flocks tested were seropositive to T. gondii, at a titre of ≥1:16, and all but three were at a titre of ≥1:64. A bimodal distribution was evident in the prevalence of titres to T. gondii suggesting that a percentage of titres ≤1:64 may have been non-specific. Of the sera tested for C. fetus fetus, 1,644/3,429 (48%) were positive to at least one of the four test antigens at titre of ≥1:10. Only 34/298 (11%) flocks tested for C. fetus fetus were completely seronegative. The percentage of seropositive ewes to both T. gondii and C. fetus fetus was significantly higher in the North Island than the South Island. CONCLUSIONS: The study demonstrated that exposure to these two important infectious abortifacients was both considerable and widespread. Minimum titres were postulated to establish a 'cut-off' for a positive result and to allow comparison with past and future studies. The bimodal distribution evident for T. gondii suggested a titre of 1:64 may be an appropriate cut-off. The widespread on-farm exposure probably stimulates the immune response of vaccinated ewes. CLINICAL RELEVANCE: Further studies are required to confirm the clinical significance of flock-based antibody responses, and to validate their use in identifying recently aborted ewes, especially where there are no aborted fetuses for examination.

Identification of an abundant allergen from the sheep louse, Bovicola ovis.

Infestation of sheep with the louse Bovicola ovis is common worldwide and leads to an allergic dermatitis referred to as 'scatter cockle'. IgE from an infested lamb was used in immunoaffinity chromatography to purify allergens from crude preparations of whole B. ovis and its faeces. SDS-PAGE of the affinity-purified eluates from both preparations showed a dominant band with M(r) of 28.5 kDa. Spleen cells from a mouse immunised with B. ovis faecal antigens were used to produce hybridomas which were screened by ELISA to identify those producing monoclonal antibodies (mAb) to the allergens purified by IgE immunoaffinity chromatography. Western blotting demonstrated that all of the mAbs examined recognised the 28.5 kDa allergen. The allergen, purified using immunoaffinity columns constructed with one of the specific mAbs, was shown to cause immediate and late-phase responses on intradermal skin testing in B. ovis-infested but not in naïve lambs. Levels of serum IgE specific for the purified allergen were significantly higher in infested than in naïve lambs (P < or = 0.0025). N-terminal and internal amino acid (aa) sequences obtained from the purified 28.5 kDa allergen were used to design primers to amplify a partial cDNA probe from B. ovis cDNA by PCR. The amplified probe was radiolabeled and used to screen a B. ovis cDNA library. The complete nucleotide sequence of the allergen was determined from the sequences of the positive clones from the library. The full-length cDNA encodes a 255 aa protein including a secretory leader sequence of 26 aas and a mature protein of 229 aas. The encoded protein showed strong homology to several hypothetical proteins of unknown function from diverse species and weak homology with lipid-binding proteins of Xenopus tropicalis and Galleria mellonella. This is the first allergen to be identified from a louse and it has been designated Bov o 1 in accordance with the criteria of the World Health Organization/International Union of Immunological Societies Allergen Nomenclature Subcommittee.

Pathophysiology in Teladorsagia (Ostertagia) circumcincta-infected sheep selected for high fleece weight.

Resilience to parasitism is considered to be the maintenance of growth and production during infection, probably associated with an immune response with lesser detrimental effects on the host relative to adverse effects on the parasite. Resilience to infection with Teladorsagia circumcincta was investigated in lambs from a flock selected for forty generations for high fleece weight (HFW), but with higher FEC and worm burdens than their unselected control (C) flock run in parallel. After recovery from surgery to implant abomasal cannulae, four parasite-naïve lambs from each flock were infected intraruminally at 6.5 months-of-age with 50,000 T. circumcincta L3, then from Day 35 to 70 post infection with 10,000 larvae at weekly intervals. Blood, abomasal fluid and faecal samples were collected daily to Day 35 and thence twice weekly for measurement of serum gastrin and pepsinogen concentrations, blood eosinophils, abomasal pH and FEC. Abomasal worm counts were made after necropsy on Day 94. Skin biopsies were collected weekly for estimation of the percentage of wool follicles containing paracortical cells. Total serum immunoglobulin and IgG1, IgG2, IgA and IgM titres specific for T. circumcincta antigens were estimated twice weekly to Day 42 p.i., then weekly. After the primary challenge, FEC were higher in the HFW lambs, whereas neither group shed many eggs during the 5-week trickle infection; worm burdens were small at post mortem. Resilient HFW lambs showed a lesser inflammatory response, but relatively small differences in abomasal secretion. Circulating eosinophil counts increased moderately in both groups, less in the HFW lambs, during the primary infection and more markedly during the subsequent trickle infection, when the increase in the C lambs became significantly greater. All measured serum antibody titres were low in both groups throughout. Selection for HFW altered the wool characteristics of parasite-naïve lambs (fewer follicles containing paracortical cells). There was a slower increase in the percentage of follicles containing these cells after primary infection. Abomasal function was similar in the two groups, both exhibiting typical increases in abomasal pH and serum gastrin and pepsinogen concentrations. The most marked differences in the HFW lambs were a greater rise in serum pepsinogen during the primary infection and the 2-day delay in onset of hypoacidity. Resilience to parasitism in this flock is consistent with maintenance of wool quality and small differences in abomasal secretion resulting from an attenuated immune response causing fewer detrimental effects on host tissues.

Protein supply influences the nutritional penalty associated with the development of immunity in lambs infected with Trichostrongylus colubriformis.

The influence of dietary protein supply on the nutritional penalty associated with the acquisition phase of the immune response to gastrointestinal nematodes in lambs was investigated. Groups of lambs were offered either a low-protein diet (L; 62 g metabolizable protein (MP)/kg dry matter (DM)) or high-protein diet (H; 95 g MP/kg DM) while being either infected with the equivalent of 2.000 L3 Trichostrongylus colubriformis/day (IF), similarly infected and concurrently immuno-suppressed with methylprednisolone acetate (ISIF), immuno-suppressed only (IS) or kept as uninfected controls (C). Body composition of all animals was measured on days -8 and 76 of infection using X-ray computed tomography. Temporal changes in serum phosphate and serum albumin concentrations, which provided an indicator of pathological damage, in addition to patterns of total daily nematode egg excretion and comparative worm burdens at slaughter indicated that a protective immune response was developed in H-IF, but not L-IF, H-ISIF or L-ISIF groups. Compared to their respective non-infected controls, the gross efficiency of use of metabolizable energy (ME) for net energy (NE) deposition in the carcass was reduced by 0.23 in H-IF (P < 0.05), 0.13 in H-ISIF (P > 0.05), 0.49 in L-IF (P < 0.01) and 0.23 in L-ISIF (P > 0.05). It is concluded that the reduction in ME utilization and reduced performance, which can be attributed to the immunological response, are lessened in animals offered a high-protein diet. Furthermore, evidence is presented to indicate a possible association between T. colubriformis L3 IgA antibody production and loss of performance in lambs infected with this nematode.

The effect of corticosteroid treatment on local immune responses, intake and performance in lambs infected with Teladorsagia circumcincta.

The nutritional cost of, and the sequential cellular changes associated with the developing immune response to the abomasal parasite Teladorsagia circumcincta were investigated using corticosteroid-induced immune-suppression. Six-month-old lambs with minimal nematode experience were either infected with 4000 L3 T. circumcincta per day (group IF), similarly infected and concurrently immune-suppressed with methylprednisolone acetate (group ISIF), immune-suppressed only (group IS) or remained as controls (group C). Food intake, faecal egg count (FEC) and antibody titres in plasma were recorded weekly, worm burden at necropsy on day 63 p.i. and body composition by X-ray computed tomography on days -2 and 62 p.i. Furthermore, sequential immunological changes at the site of parasite infestation in the abomasal mucosa were measured from serial biopsy tissue samples taken from additional animals that were fitted with an abomasal cannula and either infected with the same regime as IF animals above (group CnIF) or concurrently infected and immune-suppressed as above (group CnISIF). Corticosteroid treatment resulted in greater FECs (P<0.01) and worm burdens (P<0.01) in both ISIF and CnISIF compared with IF and CnIF sheep, respectively. Infection reduced feed intake by 17% between 14 and 28 days p.i. (P<0.05) and efficiency of energy utilisation by 20% (P=0.07) in IF animals but not in ISIF animals. Mast cells, globule leukocytes and IgA in tissue biopsy samples were elevated in CnIF from 42 days p.i., all of which were abrogated by corticosteroid treatment. The ability to regulate the worm population appeared to be associated with a rise in tissue IgA concentration and numbers of globule leucocytes (GL). The results support the hypothesis that a majority of the production losses that occur during infection of lambs with T. circumcincta in lambs are a consequence of the host immune response. These findings may have implications for regimes that promote the development of a strong host immune reaction to gastrointestinal parasites in lambs.

The impact of components of fine particulate matter on cardiovascular mortality in susceptible subpopulations.

BACKGROUND: Several studies have demonstrated associations between daily mortality and ambient particulate matter less than 2.5 microns in diameter (fine particles or PM2.5). Few, however, have examined the relative toxicities of PM2.5 constituents, including elemental carbon and organic carbon (EC and OC, respectively), nitrates and transition metals. There is also little information about whether associations between PM2.5 constituents and mortality are modified by socioeconomic and demographic factors. AIM: To examine associations of daily cardiovascular mortality with PM2.5 and its constituents after stratification by gender, race/ethnicity and education, using data from six California counties during 2000 to 2003. METHODS: The association of daily counts of cardiovascular mortality with PM2.5 components was analysed using time-series regression analyses. Poisson models with natural splines were used to control for time-varying covariates such as season and weather. Separate models were run after stratification by gender, race/ethnicity (White, Hispanic, Black) and education (high school graduation or not). Models were run for each county and results were combined using random effects meta-analysis. RESULTS: Daily counts of cardiovascular mortality were associated with PM2.5 and several of its species including EC, OC, nitrates, sulphates, potassium, copper and iron. For many of these species, there were significantly higher effect estimates among those with lower educational attainment and Hispanic individuals. For example, while essentially no association was observed for individuals who graduated from high school, an interquartile change in several of the components of PM2.5 was associated with a 3-5% increase in daily mortality among non-high school graduates. CONCLUSION: There is evidence that several PM2.5 constituents may represent important contributors to cardiovascular mortality. Many of these constituents are generated by motor vehicles, especially those with diesel engines, and by residential wood combustion. In addition, factors associated with low educational attainment may increase susceptibility to PM2.5 and its components.

Does suckling offer protection to the lamb against Teladorsagia circumcincta infection?

This study tested the hypothesis that milk has a direct effect on the establishment of infection with Teladorsagia circumcincta, and provides information on the effects of suckling on resilience to infection in young lambs. Of 46 six-week-old twin-born lambs, one from each twin was allowed to continue suckling (S-) and its twin-weaned (W-) while both were concurrently infected with an average of either 0 (-0; n=7/group), 250 (-250; n=8/group) or 1000 (-1000; n=8/group) third stage infective larvae (L3) of T. circumcincta per day, providing six treatment groups. All groups grazed minimally contaminated pasture, and after 42 days were slaughtered for necropsy. Low pasture larval contamination was confirmed in W0 and S0 lambs by faecal egg counts (FEC) of less than 30 eggs per gram (EPG) and burdens of less than 140 worms. There was no difference in FEC between weaned and suckled lambs. Within infection regime, total worm burdens were 55-60% greater in the weaned compared with their suckled counterparts (P=0.05), and represented 27 and 17%, respectively, net establishment of larvae. The greater worm burdens of both groups of weaned animals, which compared with their suckled counterparts, and of those infected with 1000 compared with 250 larvae per day, were associated with shorter female adults that had fewer eggs in utero, perhaps indicating intra-worm population regulation, but highlighting the limitation of FEC in assessing nematode burdens of such young lambs. There was no effect of infection on live weight gain of either weaned or suckled groups and the possibility was raised that, in such young lambs, immune unresponsiveness may be responsible. The major benefit of continued milk consumption appears to lie more in providing nutrients for enhanced growth rather than in improving resilience of the lambs to infection.

Heritability of resistance to infestation with the body louse, Bovicola ovis, in Romney sheep bred for differences in resistance or resilience to gastro-intestinal nematode parasites.

The inheritance of resistance to louse infestation and the related allergic skin disease, cockle, was examined in Romney lambs. The lambs used in the study were the 2001- and 2004-born progeny of four experimental breeding lines ("Resistant", "Susceptible", "Resilient" and "Control") developed as part of a long-term study of the genetics of host resistance (maintenance of low faecal egg count (FEC) under nematode challenge) or resilience (maintenance of health and productivity under nematode challenge irrespective of FEC) to nematode parasites in sheep. Between 13 and 22 progeny (equally distributed between males and females, where possible) from each of five sires in each line were selected each year for this trial. All lambs (n=701) were examined for lice (Bovicola ovis) before artificial infestation; in 2001 the lambs were free of natural infestation, whilst in 2004 naturally acquired infestation was evident. In November 2001 and May 2002, approximately 60 B. ovis were transferred to each lamb, followed by monitoring at approximately 2-monthly intervals until August 2002. Similar procedures, but with fewer monitoring times, were repeated on the 2004 lambs. Overall, lambs in the Control line were significantly more susceptible to louse infestation and cockle compared with those in the other three lines (P<0.001). Least squares-means (SEM) of log-transformed louse score for the control, resistant, susceptible and resilient lines, respectively, were 2.178 (0.045), 1.499 (0.050), 1.618 (0.050) and 1.587 (0.044), and for cockle score were 1.36 (0.05), 0.76 (0.05), 0.95 (0.05) and 0.78 (0.05). From all progeny together, the heritability of log-transformed louse score was 0.22 (Standard Error (SE) 0.06) in autumn and 0.34 (SE 0.08) in winter, with a value of 0.44 (SE 0.09) when these data were combined. These estimates were similar to those obtained for resistance to gastro-intestinal nematodes in these breeding lines, using log-transformed FECs. Heritability estimates for cockle score in autumn, winter and when combined were 0.06 (SE 0.04), 0.45 (SE 0.09) and 0.40 (SE 0.09), respectively. The genetic correlations of mean log-transformed louse score with mean cockle score and levels of two different louse antigens in wool were, respectively, 0.97 (SE 0.04), 0.96 (SE 0.08) and 0.95 (SE 0.09). However, there was no significant genetic correlation between louse scores and FEC. These results suggest that selective breeding would be effective in reducing louse infestation and cockle in sheep, but that differences in louse burdens were not related to differences in nematode burdens as indicated by FECs.

The transfer of maternal IgE and other immunoglobulins specific for Trichostrongylus colubriformis larval excretory/secretory product to the neonatal lamb.

The transference of immunoglobulins from six New Zealand Romney ewes to their lambs was examined. Immunoglobulin levels were determined in ewe plasma, colostrum and lamb plasma shortly after birth and before the lambs fed, in lamb plasma 2 days after birth, and lamb plasma, ewe plasma and milk 30 days after parturition. Levels of total IgE, and IgE, IgG1, IgG2, IgM, and IgA with specificity for Trichostronglus colubriformis third stage larval secretory/excretory products (TcL3E/S) were determined. Mean levels of total IgE were three times higher in colostrum than in parturient ewe plasma while only trace amounts were detected in milk at 30 days after birth (107.7, 34.3, and 0.2U ml(-1), respectively, differences between means P< or =0.01). Mean total IgE in lamb plasma rose from being undetectable before suckling to levels comparable to those of the ewes by 2 days after birth (21.7U ml(-1)) and then declined to low levels by 30 days (0.4U ml(-1)). Total IgE levels in lamb plasma were significantly correlated with levels in ewe plasma and colostrum (r=0.91, P< or =0.01; r=0.96, P< or =0.003, respectively). The transference of TcL3E/S-specific IgE, IgG1 and IgA was substantial with mean levels of these antibodies in lamb plasma at 2 days comparable to that in parturient ewe plasma (absorbance levels in lamb plasma of 0.283, 0.537, and 0.334, respectively). Proportionally less maternal IgM and IgG2 appeared to be transferred to the lambs (absorbance of 0.112 and 0.081, respectively). Levels of TcL3E/S-specific IgE and IgG1 in lamb plasma at 2 days were significantly correlated with levels in parturient ewe plasma and colostrum (r=0.89 and 0.82, 0.85 and 0.96; all P< or =0.05, respectively). These results indicate that IgE is concentrated in ewe colostrum and that substantial amounts of maternal IgE are transferred to lambs via colostrum. Further, the results suggest that humoral immunity against gastro-intestinal nematode parasites and potentially other parasites in colostrum-fed lambs may approximate that of the ewe. The implications of the transference of humoral immunity through colostrum in ruminants for the passive protection and the development of active immunity against parasites remains to be fully explored.

Nonfatal occupational injury among California farm operators.

We conducted a population-based telephone survey addressing farm-work-related (FWR) injuries among California farm operators. Of 1947 participants (80.4% response), 135 farm operators reported 160 FWR injuries in the preceding year, yielding a one-year cumulative incidence for any FWR injury of 6.9% (95% CI 5.8%-8.2%), or a mean 8.2 FWR injuries per 100 farmers in the preceding year (95% CI 6.8-9.7). Multiple injury events in the same individual occurred more frequently than predicted by chance. Sprains and strains (29.4%) were the most frequently reported injury and predominantly involved the back. Overexertion represented the most frequent external cause (24.2%), followed by machinery (14.3%), falls (13.0%), and animals (12.4%). Factors associated with FWR injury included white ethnicity (OR 3.19; 95% CI 1.38-7.36), increased annual hours worked on the farm, low levels of administrative work, and increased percentage of time working with livestock. FWR injury experience of California farm operators is comparable with that reported for other agricultural populations. Above-expected frequency of multiple injuries supports involvement of personal or environmental risk factors. Preventive efforts should focus on higher-risk groups and preventing overexertion and muscle strain and injury related to machinery, falls, and animals, especially livestock.

Production and immunological responses associated with controlled-release-capsule vs 5-drench preventive anthelmintic programmes for parasite control in lambs.

AIMS: To determine whether: a) using a controlled-release anthelmintic capsule (CRC) instead of a programme of 5 oral drenches administered at 3-4 week intervals, would delay the development of anti-parasite immunity in lambs; b) the use of ivermectin instead of albendazole, administered either as a CRC or as a programme of 5 oral drenches, would delay the development of anti-parasite immunity in lambs; c) lambs treated with CRCs would have higher liveweight gains than lambs drenched orally 5 times at 3-4 week intervals, and; d) delayed onset of anti-parasite immunity is associated with reduced liveweight gains in the period following anthelmintic treatment. METHODS: Three field trials were conducted, 1 on a research farm and 2 on commercial sheep farms, in which groups of 30 lambs were treated with either a CRC containing albendazole, a CRC containing ivermectin, 5 oral drenches with albendazole, or 5 oral drenches with ivermectin, administered at 3-4 week intervals. Liveweights and faecal nematode egg counts (FECs) were recorded in all trials. Immunoglobulin-G (IgG) antibody levels to Ostertagia circumcincta and Trichostrongylus colubriformis adult and larval antigens were measured in Trials 1 and 3, and fleece weights and resistance of animals to nematode challenge infection were measured in Trial 1. RESULTS: CRC-treated lambs had higher levels of antibodies to O. circumcincta infective-stage larvae (L3) than orally drenched lambs in Trial 3, but no other immunological differences due to mechanism of delivery were detected. Antibody levels were lower in lambs treated with ivermectin than albendazole, as a CRC or oral drench in Trial 1, but this was not associated with any measurable effects on FEC or productivity. No significant differences (p>0.05) were detected between drench types (albendazole vs ivermectin) or delivery mechanisms (CRC vs oral drenching) in any of the production parameters measured, in any of the trials. Albendazole-CRCs failed to control FECs in all 3 trials. CONCLUSIONS: Although some differences between treatments in antibody levels were detected these were not associated with measurable differences in level of parasitism or productivity of lambs. CRC use did not appear to offer substantial gains in productivity over a structured programme of 5 oral drenches administered at 3-4 week intervals.

The contribution of cytologic imprints of stereotactically guided core needle biopsies of the breast in the management of patients with mammographic abnormalities.

Between 1995 and 1996, 96 consecutive patients with nonpalpable breast lesions detected by abnormal mammogram underwent core needle biopsies under stereotactic guidance at Johns Hopkins Bayview Medical Center. The cytologic diagnoses rendered on touch imprints and the histopathologic diagnoses made on the core needle biopsies were retrospectively reviewed to ascertain the accuracy and the validity of this procedure. These imprints were made of the cores as on-site evaluation in order to assist the radiologist. Separate diagnoses were rendered on the imprints and the cores. Follow-up excisional/open biopsies were then correlated to determine the usefulness of making touch imprints from the core needle biopsies toward the overall management of a patient with an abnormal mammogram. The core needle biopsies were obtained with a 14-gauge needle and biopsy gun. The cytologic diagnoses rendered on touch imprints and histopathologic diagnoses on core needle biopsies were compared and the concordance rate was determined. The subsequent surgical follow-up was analyzed and correlated with the imprint cytology and the core needle biopsy interpretation to ascertain the pathologic outcome. A total of 100 cases were reviewed: 4 patients had two lesions biopsied. Eighty-four cases showed complete cytohistologic correlation, that is, a high concordance rate. These 84 cases were divided into four categories: malignant (24), atypical (2), benign (55), and unsatisfactory (3). Of these concordant cases, there were 34 subsequent excisional biopsies and all except one confirmed the core needle biopsy diagnosis. The exception had a benign touch imprint and core but the excisional biopsy showed multifocal ductal carcinoma in situ. Of the 100 cases, 16 were nonconcordant (the cytologic diagnosis fell into a different category from the histologic diagnosis). Seven of these nonconcordant cases resulted in excisional biopsies and all but one showed the core diagnosis to be correct. The only exception was a case with atypical cytology and a benign core biopsy with the follow-up excision showing atypia. The rest of the nonconcordant cases with atypical imprints and benign cores had no follow-up surgery, showing that the clinicians are inclined to depend on the core biopsy diagnosis. While our study demonstrates the accuracy and concordance of cytologic touch imprints, the surgical follow-up data reveal that there does not appear to be any additive value to rendering a separate diagnosis on touch imprints of core needle biopsies.

Death as a complication of peripherally inserted central catheters in neonates.

We report 2 neonatal deaths caused by cardiac tamponade related to peripherally inserted central catheters (PICCs). A total of 3 deaths were noted for 390 PICCs placed, giving an incidence of 0.76%. To determine the magnitude of neonatal death related to PICCs, directors of neonatal intensive care units in the United States were surveyed by means of a questionnaire. Myocardial perforation and pericardial effusion were reported by 29% and 43%, respectively. Deaths were attributed to PICCs by 24% of the respondents. Uniform guidelines need to be formulated to avoid this complication.