Short communication: Temporal profiles of colostrum and milk haptoglobin and substance P in early lactation multiparous Holstein cows

Milk markers have the potential to aid in the detection of cow disease in early lactation if the automation of milk analysis becomes commonplace. Characterising temporal profiles of milk markers in dairy cows will improve the understanding of basal concentrations in clinically healthy cows. The objective of this observational study was to characterise the variation and temporal profiles of colostrum and milk haptoglobin (Hp) and substance P concentrations within 21 days postcalving in clinically healthy multiparous Holstein dairy cows. Ninety Holstein dairy cows from a commercial dairy herd were included. Milk samples were collected on the day of calving (day 0), and on days 1 to 4, 7, 14, and 21 postcalving and concentrations of Hp and substance P in colostrum (days 0 to 3) and milk (days 4, 7, 14, and 21) were determined using Enzyme Linked Immunosorbent assay. Haptoglobin and substance P concentrations were, on average (raw means ± SD), 0.40 ± 0.26 µg/ml and 56.2 ± 38.7 pg/ml in colostrum, respectively, and 0.23 ± 0.23 µg/ml and 37.1 ± 27.8 pg/ml in milk, respectively. Haptoglobin and substance P were elevated and greatest 1 day postcalving (least squares mean ± SE of the mean; 0.53 ± 0.05 µg/ml and 46.5 ± 3.64 pg/ml, respectively) and substance P varied widely within 21 days postcalving. The presence of substance P in dairy cow colostrum was not documented previously. Elevated concentrations of Hp and substance P immediately postcalving may be due to physiological roles these inflammatory markers have in the dairy cow or neonate or may simply represent an accumulation in colostrum before the first milk is removed.

Exploring farmers' attitudes and determinants of dairy calf welfare in an expanding dairy sector

The 2015 European Union milk quota abolition initiated considerable expansion in the dairy sector in many European Union countries, most significantly in Ireland. However, this major production increase also had wider societal implications, such as negative environmental and animal welfare consequences. In this article, we used survey data of 441 Irish dairy farmers to assess farmers' attitudes toward the welfare of farmed animals and dairy calves, as well as the reputation of the Irish dairy sector. We also explored how expansion, breeding, calf management, and farmer characteristics relate to calf welfare outcomes (i.e., calf mortality, calf export, and premature culling). In relation to attitudes, farmers expressed a general concern toward animal welfare, while views toward dairy calves and industry reputation were mixed. We used Ward's linkage hierarchical cluster analysis to group farmers based on their attitudes. The cluster analysis revealed 3 distinct groups relating to high, medium, and low animal welfare concern. Herd expansion was negatively associated with being in a higher animal welfare concern cluster, whereas beef trait-focused breeding was positively associated with it. In relation to dairy calf welfare outcomes, our econometric analyses based on multiple regression and binary choice models revealed that expansion was positively associated with calf mortality, whereas improved breeding and calf management factors had a negative association. In addition, being in the high animal welfare concern cluster was negatively associated with calf mortality. Furthermore, breeding decisions were significantly associated with whether calves were exported, and being in the high animal welfare concern cluster was negatively associated with the probability that calves were sent for live export. Finally, farmers' breeding and calf management decisions were associated with premature culling of calves. Overall, this article revealed strategies worth promoting to improve dairy calf welfare, such as beef trait-focused breeding leading to greater dairy-beef integration.

0218 Biomathematical Modeling Predicts Fatigue Risk in General Surgery Residents

Introduction

Fatigue and its effects on performance have long been a concern in medicine. Evidence exists that current duty-hour restrictions for resident trainees have a limited impact on physician wellbeing and patient safety, prompting renewed efforts to address this threat. In this study, sleep patterns of general-surgery residents were used to optimize a biomathematical model of performance for use as a tool for fatigue risk management with residents.

Methods

General surgery residents based at a multi-hospital, general surgery residency program were approached for participation in this study. Enrolled residents wore actigraph devices for 8 weeks and completed subjective sleep assessments. Sleep data and shift schedules were then input into the Sleep, Activity, Fatigue and Task Effectiveness (SAFTE) Model to assess predicted cognitive performance. Performance was compared to an “effectiveness” level of 77 (equivalent to a blood-alcohol content of 0.05g/dL). Eight hours of sleep debt was considered “below reservoir criteria”.

Results

Sleep actigraphy data was collected from 22 general surgery residents. Modeling results showed that as shift lengths increased, effectiveness scores generally decreased, and the time spent below criterion (77) increased. Additionally, 11.13% of time on shift was below the effectiveness criterion and 42.7% of shifts included time spent below the reservoir criterion. Adjustments to the sleep prediction were made based on actual sleep, and performance predictions from actual sleep and the adjusted model were significantly correlated (p<.0001).

Conclusion

Despite adherence to national standards limiting work hours, current surgical resident sleep patterns and shift schedules create concerning levels of fatigue. This study illustrates how biomathematical fatigue models can predict resident physician sleep patterns and performance. Modeling represents a novel and important tool for medical educators seeking to create shift schedules that maintain physician preparedness and minimize fatigue risk.

Support

N/A

0184 Predicting Strategic Napping in Surgical Residents by Individual and Rotation Characteristics

Introduction

Strategic napping, or napping on-shift, is recommended to reduce fatigue in medical residents. The actual prevalence of strategic napping in relation to residents’ workload, schedule, or demographics is largely unquantified. This study objectively measured sleep patterns and work schedules in surgical residents working a variety of service lines over a two-month period in order to identify which resident and service line attributes predict on-shift napping.

Methods

Surgical residents from an academic surgery program in the Washington, DC area provided schedule information, completed the Epworth Sleepiness Scale (ESS), and wore sleep-tracking devices (Zulu Watch) continuously for 8 weeks. Multiple linear regression was performed to predict percent days with on-shift napping from resident demographics (age, gender, post graduate year (PGY), sleep characteristics (ESS, total sleep time (TST), sleep efficiency (SE)), schedule characteristics (shift start time, shift length, rotation length, percent days on-shift, percent night shifts), and service line characteristics (service line category, number of service lines worked).

Results

Twenty-two (n=22) residents completed the study, rotating through at least 1 of 5 different service line categories (Acute Non-Elective Surgery, Elective Surgery, Night Float, Surgical Intensive Care Unit, and Other). Residents slept an average of 6 hours within a 24-hour period (370±129 minutes) with normal SE (87.13%±7.55%). ESS scores indicated excessive daytime sleepiness (11.64±4.03). Ninety-five percent (n=21) of residents napped at least once while on shift. Residents napped on-shift approximately 32% of their working days and were most likely to nap when working between 2300-0500 hours. Earlier shift start times predicted less on-shift napping (B=-0.08,SE=0.04,β=-2.40,t=-2.09,p=0.05) while working more night shifts (B=1.55,SE=0.44,β=4.12,t=3.52,p=0.003) and shifts over 24 hours.

Conclusion

Residents take advantage of opportunities to nap on-shift, particularly when working at night. Despite naps, however, residents exhibit insufficient sleep with excessive daytime sleepiness, representing a safety risk to themselves and their patients.

Support

NA

Private animal health and welfare standards in quality assurance programmes: a review and proposed framework for critical evaluation

In recent years, 'private standards' in animal health and welfare have become increasingly common, and are often incorporated into quality assurance (QA) programmes. Here, we present an overview of the use of private animal health and welfare standards in QA programmes, and propose a generic framework to facilitate critical programme review. Private standards are being developed in direct response to consumer demand for QA, and offer an opportunity for product differentiation and a means to drive consumer choice. Nonetheless, a range of concerns have been raised, relating to the credibility of these standards, their potential as a discriminatory barrier to trade, the multiplicity of private standards that have been developed, the lack of consumer input and compliance costs. There is a need for greater scrutiny of private standards and of associated QA programmes. We propose a framework to clarify the primary programme goal(s) and measureable outputs relevant to animal health and welfare, the primary programme beneficiaries and to determine whether the programme is effective, efficient and transparent. This paper provides a theoretical overview, noting that this framework could be used as a tool directly for programme evaluation, or as a tool to assist with programme development and review.

Influence of a conspecific image of own vs. different breed on fear reactions of ewes

We observed the influence of slide images of conspecifics on fear reactions of 12 Romanov and 12 Ile-de-France ewes. Each ewe was individually tested twice in isolation: once in the presence of the projected image of an unfamiliar ewe of its own breed, and once when exposed to an image of a ewe of a different breed. Ewes' responses to a slide of an individual of their own breed differed consistently from their responses to a slide of the other breed (i.e., they displayed lower fear reactions to their own breed). There was also a significant main effect for breed of subject, which reflects breed differences in activity level and/or fearfulness. Differential responses to two-dimensional images of unfamiliar animals of own versus other breed suggest that the ewes recognized the characteristics of their breed. Moreover, the manner in which ewes responded to the slide projections indicates that those images were perceived as social stimuli.

Evaluating the prevalence of tail biting and carcase condemnations in slaughter pigs in the Republic and Northern Ireland, and the potential of abattoir meat inspection as a welfare surveillance tool

Despite extensive utilisation in epidemiological investigations of animal health, to date there has been little consideration of the value of abattoir meat inspection as a pig welfare surveillance tool. This study measured the prevalence of tail-docking, tail biting, carcase condemnations and associated financial losses of the latter (Northern Ireland only) in 36,963 pigs slaughtered in six abattoirs from the Republic of Ireland and Northern Ireland in July and August 2010. Over 99 per cent of inspected pigs had been tail-docked, while 58.1 per cent and 1.03 per cent had detectable and severe tail lesions, respectively. Producer losses resulting from carcase condemnation were estimated to be €0.37 per pig slaughtered. Enhanced capture and utilisation of meat inspection data for use in animal welfare surveillance schemes has the potential to drive improvements in production efficiency and animal welfare. However, significant differences were detected in the prevalence of carcase condemnation conditions between abattoirs and judiciaries (Republic and Northern Ireland). This reflects variation in the criteria and methods of data capture used in meat inspection in different abattoirs. Thus, the meat inspection process needs to be standardised and reformed before it can be reliably utilised in large-scale pig welfare surveillance schemes.

The effect of out-wintering pad design on hoof health and locomotion score of dairy cows

This study compared locomotion, hoof health, and lameness of dairy cows confined in either indoor free stalls (FS) or 1 of 3 out-wintering pad (OWP) designs. Out-wintering pad treatments were 1) uncovered OWP with a concrete feed apron (UP); 2) covered OWP with a concrete feed apron (CO); and 3) uncovered OWP on top of which grass was ensiled so that the cows could self-feed (SP). Cows were assigned to treatment at drying off using a randomized complete block design. They remained on treatment until calving, when they were turned out to pasture. Sole lesions, heel erosion, dermatitis, and claw hardness on both hind feet were scored according to severity at assignment to treatment, at calving, and 9 and 14 wk postpartum. Locomotion score was recorded weekly after calving for 14 wk. Incidence of clinical lameness was recorded during the treatment period and in the subsequent lactation. Treatment had no effect on sole lesion score, but scores increased over time (calving = 5.5 +/- 1.3, wk 9 = 10.8 +/- 1.3, wk 14 = 14.2 +/- 1.3, mean +/- SE). Self-fed cows had higher heel erosion scores (6.4 +/- 0.4) than FS and CO cows (4.7 +/- 0.4 and 4.7 +/- 0.4, respectively) at calving. Cows on SP had the highest dermatitis scores [1.14 (0-2) mean (interquartile range)] and FS cows the lowest [0.51 (0-0)]. Hooves were hardest at assignment to treatment (43.9 +/- 0.6) with a significant reduction in hardness at calving (40.0 +/- 0.6). The hooves of CO cows were harder than those of SP and UP cows (CO = 43.3 +/- 0.7, SP = 41.7 +/- 0.7, UP = 41.7 +/- 0.7, Shore D scale). There was no treatment effect on locomotion scores or lameness incidence. Higher dermatitis scores and heel erosion in SP may be due to exposure to excreta and moisture, because the SP treatment had no manure removal system at the feed face. In FS, the alleys and the feed face were cleaned regularly by automatic scraper, explaining the lower dermatitis scores recorded indoors. Providing shelter for OWP likely reduced exposure to environmental moisture. This ensured that the hooves of CO cows remained as hard as those of FS cows. Low correlations between hardness and pathologies indicate that other factors are involved in the development of hoof pathologies. Confining dry dairy cows on OWP does not increase locomotion scores or lameness incidence.

Infant Staphylococcal Scalded Skin Syndrome, Ireland, 2007 – preliminary outbreak report

Between February and May 2007, five confirmed cases of Staphylococcal Scalded Skin Syndrome (SSSS) were identified in full-term healthy infants born at a maternity unit in Ireland (hospital A). This hospital serves a population of 340,000 people, with over 4,500 babies born annually.

Pro-inflammatory cytokine and acute phase protein responses to low-dose lipopolysaccharide (LPS) challenge in pigs

The objective of this study was to establish the pro-inflammatory cytokine and acute phase protein responses to low-dose lipopolysaccharide (LPS) challenge in pigs and to determine whether these immune parameters could also be measured in saliva. Possible gender differences in the acute phase reaction were also assessed. At 6 weeks of age, 24 male and 24 female pigs were injected intraperitoneally with a single dose of 0 or 5 μg/kg live weight (LW) of LPS fromEscherichia coli(treatment). Matched saliva and blood samples were taken at 0, 2, 4, 8, 12 or 24 h after treatment administration. Samples were analysed for concentrations of the pro-inflammatory cytokines tumor necrosis factor-alpha (TNF-α) and interleukin-1beta (IL-1β), the acute phase proteins C-reactive protein (CRP), serum amyloid A (SAA), haptoglobin (Hp), and cortisol. Low-dose LPS administration increased plasma levels of TNF-α (P<0·001), CRP (P<0·05) and SAA (P<0·05) but did not affect plasma concentrations of IL-1β or Hp (P>0·1). Treatment by time interactions showed that plasma levels of TNF-α and CRP in LPS-treated pigs peaked at 2 h (P<0·001) and 12 h (P<0·01), respectively. Low-dose LPS injection tended to increase plasma concentrations of cortisol (P=0·056) and the response to LPS differed between genders (P<0·05), with females showing higher cortisol responsiveness to the challenge (P<0·01). Males showed higher levels of both cytokines regardless of the treatment (P<0·05), probably due to the inhibition of cytokine synthesis by cortisol. Concentrations of both pro-inflammatory cytokines were consistently detectable in saliva and were present in higher concentrations than in plasma (P<0·001). Hence, plasma TNF-α, CRP and SAA are useful indicators of sub-acute inflammation/infection in pigs as simulated by a low-dose LPS challenge and gender differences exist in the pro-inflammatory cytokine response after a low dose of LPS.

The incidence of S. aureus bacteraemia in acute hospitals of the Mid-Western Area, Ireland, 2002-2004

Concerns about healthcare-associated infections and the global crisis in antimicrobial resistance has combined to accentuate the fears around so-called &quot;superbugs&quot;. In Ireland there is no single agreed indicator regarded as a true measure of the level of methicillin resistant Staphylococcus aureus (MRSA) in hospitals. The objective of this study was to compare two crude measures of MRSA - the percentage of bacteraemia caused by MRSA and the incidence rate (per 1000 bed days used) of MRSA bacteraemia in six acute hospitals. We examined all blood cultures positive for S. aureus (methicillin sensitive and resistant) from 2002 to 2004 in the Health Service Executive (HSE) Mid-Western Area of Ireland. Hospital In-Patient Enquiry (HIPE) data was used to determine monthly in-patient bed days used. Of 245 patient episodes of bacteraemia, 119 were MRSA. The trends in the percentage of isolates that were MRSA and the incidence rate calculated were compared. The incidence rate appears to be a more reliable and robust indicator of MRSA in hospitals than the percentage. Despite many difficulties in interpreting indicators of MRSA they should not preclude the regular publication of data at least at regional level in Ireland.

The incidence of S. aureus bacteraemia in acute hospitals of the Mid-Western Area, Ireland, 2002-2004

Concerns about healthcare-associated infections and the global crisis in antimicrobial resistance has combined to accentuate the fears around so-called "superbugs". In Ireland there is no single agreed indicator regarded as a true measure of the level of methicillin resistant Staphylococcus aureus (MRSA) in hospitals. The objective of this study was to compare two crude measures of MRSA--the percentage of bacteraemia caused by MRSA and the incidence rate (per 1000 bed days used) of MRSA bacteraemia in six acute hospitals. We examined all blood cultures positive for S. aureus (methicillin sensitive and resistant) from 2002 to 2004 in the Health Service Executive (HSE) Mid-Western Area of Ireland. Hospital In-Patient Enquiry (HIPE) data was used to determine monthly in-patient bed days used. Of 245 patient episodes of bacteraemia, 119 were MRSA. The trends in the percentage of isolates that were MRSA and the incidence rate calculated were compared. The incidence rate appears to be a more reliable and robust indicator of MRSA in hospitals than the percentage. Despite many difficulties in interpreting indicators of MRSA they should not preclude the regular publication of data at least at regional level in Ireland.

Incontinence in adult females with cystic fibrosis: a Northern Ireland survey

The objectives of this survey were to establish the prevalence, onset, severity and impact of incontinence and attitudes towards the availability of advice and treatment in female adults with cystic fibrosis (CF) in Northern Ireland. All female patients (n=59) at the Northern Ireland Regional Adult CF Centre were posted a questionnaire on incontinence. Leakage of urine occurred in 14/46 respondents. Leakage of urine occurred when chest was bad in 8/14 patients and when chest was good or bad in 3/14 patients. Patients reported that their bladder problem affected their ability to perform airway clearance or cough (13/14), and exercise (4/14). The main reason given for the patients who did not seek help for their incontinence (10/14) was that they were too embarrassed. This study highlights that patients with CF are reluctant to seek treatment for incontinence despite the impact this condition can have.

Effects of estrogen replacement therapy on the circadian rhythms of serum cortisol and body temperature in postmenopausal women

Estrogen replacement therapy (ERT) seems to enhance longevity in women. Both gender and aging have been shown to influence the regulation of circadian rhythms, yet little is known about the effect of ERT on circadian regulation. The aim of this study was to determine the effects of ERT (oral conjugated estrogen: Premarin, 0.625 mg) for 6-8 weeks on circadian serum cortisol by continuous blood sampling every 15 min for 24 h with simultaneous measurements of body temperature in six healthy postmenopausal women (range, 54-61 years). The results are presented as median values (range in quartiles). The circadian amplitude of cortisol increased during ERT from 20.20 (18.35, 23.61) to 25.97 (24.94, 27.74) microg/dL (p = 0.016), whereas the timing of nocturnal nadir and morning acrophase did not differ significantly. ERT lowered the 24-h body temperature from 37.03 degrees C (36.95 degrees C, 37.07 degrees C) to 36.90 degrees C (36.77 degrees C, 36.97 degrees C) (p = 0.038), but did not alter the peak and trough body temperatures significantly. These findings are noteworthy because the increased circadian amplitude of serum cortisol during ERT contrasts with the reduction in circadian amplitude seen with normal aging. The reduction in body temperature confirms the regulatory effect of ERT in thermoregulation and has implications regarding the correlation between basal metabolic rate and life span.

T cell receptor usage by HLA-DR3-specific T cell clones isolated from a renal allograft

In order to evaluate the T cell receptor (TCR) usage by clones of human allograft infiltrating lymphocytes, this study utilized polymerase chain reaction (PCR) amplification of TCR transcripts from five clones which were previously shown to react with a human leucocyte antigen (HLA)-DR3 mismatch between a living related kidney donor and recipient. The five CD4+ (CD8-) clones, which were selected for TCR analysis, proliferated in response to HLA-DR3 and three of the clones were also cytotoxic against the same target cells. After identification of the TCRAV and TCRBV usage of the clones, the sequence of the TCR alpha and beta were determined by direct sequencing of the PCR product. The results indicate that several different TCRAV and TCRBV gene segments are used among the different clones, but the two clones that were both cytotoxic and proliferative in response to HLA-DR3 shared identical TCRAV27-J42-C and TCRBV13-D1-J1S2-C1 transcripts. The additional three clones showed various TCRAV and TCRBV transcripts, but evaluation of the CDR3 region of the TCR beta chain, corresponding to the peptide antigen binding sites, demonstrated shared amino acid motifs which resulted both from germline sequences and combinations of n-region and germline-derived codons. These results suggest that the repertoire for anti-HLA-DR3-reactive clones can include a diverse expression of TCR, but there may be selection for some clones, as well as conserved motifs in the CDR3 region of anti-DR3 specific clones.

Solitary cavernous hemangioma of small intestine. Case report and literature review

We describe a 14-year-old boy with a solitary cavernous hemangioma in the proximal small intestine that caused recalcitrant iron deficiency anemia beginning at 3 years of age. After a number of attempts to ascertain the cause of the anemia were unsuccessful, the vascular tumor was ultimately diagnosed in the jejunum, approximately 80 cm distal to the ligament of Treitz. We discuss the differential diagnoses of vasoformative intestinal lesions and review the literature on enteric cavernous hemangiomas in childhood.

Interspecific and intraspecific horizontal transfer of Wolbachia in Drosophila

Cytoplasmic incompatibility (CI) in Drosophila simulans is related to infection of the germ line by a rickettsial endosymbiont (genus Wolbachia). Wolbachia were transferred by microinjection of egg cytoplasm into uninfected eggs of both D. simulans and D. melanogaster to generate infected populations. Transinfected strains of D. melanogaster with lower densities of Wolbachia than the naturally infected D. simulans strain did not express high levels of CI. However, transinfected D. melanogaster egg cytoplasm, transferred back into D. simulans, generated infected populations that expressed CI at levels near those of the naturally infected strain. A transinfected D. melanogaster line selected for increased levels of CI expression also displayed increased symbiont densities. These data suggest that a threshold level of infection is required for normal expression of CI and that host factors help determine the density of the symbiont in the host.

Heterotopia of gastric mucosa and liver involving the gallbladder. Report of two cases with literature review

Two cases of heterotopic tissue involving the gallbladder are presented (one gastric mucosa, the other liver), and the relevant literature is reviewed highlighting problems in differential diagnosis and complications, particularly with regard to gastric mucosal heterotopia. A firm diagnosis of gastric heterotopia is based on the presence of fundic mucosa replete with parietal and chief cells; a clear distinction from intestinal metaplasia should be made, but at times may be difficult. Potential complications include mucosal ulceration, obstruction, and hemorrhage. Of 39 patients presented, about half were 30 years of age or younger, and only nine have had calculi noted in the cholecystectomy specimen. Heightened awareness of gastric heterotopia with separation of smooth-muscle bundles may help to avoid a malignant diagnosis. Hepatic tissue involving the gallbladder that is completely separate from the main part of the liver is an even rarer form of heterotopia that should be distinguished from an accessory lobe.

Surgical management of anorectal infection in the leukemic patient

Anorectal infections are a common complication in immunocompromised patients. Such infections are multifactorial in etiology, often promoted by breaks in the anorectal mucosa and depressed leukocyte counts, both secondary to chemotherapy. Because of altered immune response to infection, diagnosis of anorectal infections in leukemic patients is often delayed, with a resultant mortality of up to 78%. Management is typically supportive for fears of extension of infection or non-healing of wounds with surgical intervention. We recently encountered a 17-year-old woman who presented with an anorectal infection heralding the onset of acute nonlymphocytic leukemia. Because of her unusual presentation, chemotherapeutic induction occurred subsequent to surgical drainage of an anorectal abscess. She demonstrated adequate healing of her wounds in the early post-operative, post-induction period. Her case and a review of the current management of anorectal infections in patients with leukemia are presented.

A computerised medical manpower database--an assessment of its value in medical education

The development of a computerised medical and dental manpower database for medical education in the West of Scotland is described. The purpose of the database is to provide the West of Scotland Committee for Postgraduate Medical Education with information on the career patterns of doctors and dentists, and to assist in the planning of training. Data collection is from a wide variety of sources and confidentiality and security are paramount. A standing committee, representing all professional interests, has been central to the development of the database. It has acted as policy-maker and adviser, and has been concerned with the way in which the data is used. At each stage in the development, this committee has been fully consulted. The data collected is both of a personal and professional nature and is validated annually by sending a copy of the data to each doctor or dentist for checking. This has highlighted some deficiencies in the data, which now contains information on over 6,000 doctors and dentists. Requests for information from the database are carefully scrutinised by the standing committee before the data is released.

Gel filtration separation of bound and free antigens in radioimmunoassay of prostaglandin F2 alpha

A technique applying the principles of gel filtration to separate the antibody-bound antigen for radioimmunoassay of PGF2 alpha is described. The procedure involves addition of the entire assay incubate to a column of Sephadex G-75 and elution of the antibody-bound fraction directly into a scintillation vial. Subsequent rinsing elutes the free fraction enabling the column to be re-used. The validity of this method for the direct measurement of PGF2 alpha in a standard tissue culture medium is demonstrated and its advantages over other separation techniques discussed.

Release of prostaglandins during contraction of the human umbilical vein on reduction of temperature

Flow rate was measured through the vein of the human isolated umbilical cord perfused at constant pressure (40 mmHg) at 37.5 degrees C and 20 degrees C. At the latter temperature the flow was decreased by 50.9% when compared with a mean of 201 ml/min at 37.5 degrees C indicating venospasm. Indomethacin (10 microgram/g) effected a highly significant reduction in the venous spasm caused by lowering the temperature. After indomethacin pretreatment, changing the cord temperature from 37.5 degrees C to 20 degrees C caused a mean decrease in flow of only 3.1%. When the effluent from the vein was passed over rat isolated stomach fundus and colonic strips, cooling of the cord was accompanied by contractions of the isolated tissues characteristic of prostaglandins. These results suggest that prostaglandins are involved in temperature-induced closure of the human umbilical vein after birth.