Anastomotic leak does not affect long-term and longitudinal functional outcomes after ileal pouch surgery for ulcerative colitis when managed aggressively.

BACKGROUND: Ileal pouch-anal anastomosis (IPAA) is an effective surgical alternative to a permanent ileostomy following proctocolectomy in patients with ulcerative colitis (UC). Anastomotic leakage (AL) is a serious postoperative complication of an intestinal anastomosis that is associated with increased morbidity and mortality. The aim of this study was to evaluate the longitudinal long-term functional outcomes of patients who had IPAA that was complicated by AL. METHODS: A retrospective longitudinal cohort study was performed of patients who had an IPAA procedure at a tertiary referral centre and a metropolitan private centre in Australia, over a 14-year period (October 2003-October 2017). The long-term functional outcome was assessed using objective clinical measures such as the number of bowel motions during the day and overnight, ability to defer defaecation and the presence of faecal incontinence, and repeated at annual intervals. RESULTS: A total of 138 patients [mean age 38.5 (± 16.9) years, 72 males] satisfied the inclusion criteria. AL was diagnosed in 14 (10%) patients [mean age 38.8 (± 17) years, 10 males], 11 (79%) of which were managed with surgery. The median bowel motion frequency during the day and overnight remained stable over a median of 62 (28-91) months follow-up, with no significant difference between those who had AL or not (p = 0.6, p = 0.1 respectively). The incidence of faecal incontinence remained low, and the majority of patients in both groups were able to defer defaecation for more than 60 min. Six patients (4.3%) had their pouch excised. CONCLUSIONS: There is no statistical difference in longitudinal function between patients who experienced AL after IPAA surgery for UC compared with those who did not. Therefore, an acute AL does not negatively impact long-term functional outcomes in IPAA patients.

Drain fluid amylase as a sensitive biomarker for the early detection of anastomotic leakage in ileal pouch surgery.

AIM: We studied the levels of amylase in drain fluid to investigate its utility as a biomarker of anastomotic leak in ileal pouch patients who did not have a covering loop ileostomy. The luminal contents of the small intestine are high in amylase. Ileal J pouches are formed for restoration of continuity in patients with ulcerative colitis after removal of the colon and rectum. A drain is placed alongside the ileal pouch in the pelvis. METHOD: This study is a retrospective analysis of prospectively collected daily drain fluid amylase levels in consecutive patients undergoing restorative proctectomy and ileal J pouch anal anastomosis, without a covering loop ileostomy, between November 2016 and April 2018. RESULTS: Thirteen patients underwent surgery without a covering loop ileostomy. Two patients suffered an anastomotic leak and were returned to theatre, one on day 5 and the other on day 6 postoperatively. The mean daily drain fluid amylase level in those who did not leak was between 25 and 46 U/l with a range of 22-139 U/l for all samples collected. In the two patients who suffered a clinical leak the drain fluid amylase level rose to 22 432 and 10 212 U/l on the day of clinical leak diagnosis. The mean rectal tube (intraluminal) amylase level was 63 097 U/l as measured on day 1 postoperatively. CONCLUSION: In this small cohort of patients, the measurement of drain fluid amylase is a highly sensitive biomarker of clinical anastomotic leak.

Surgical outcomes in steroid refractory acute severe ulcerative colitis: the impact of rescue therapy.

AIM: The advent of rescue medical therapy (cyclosporin or infliximab) and laparoscopic surgery has shifted the paradigm in managing steroid refractory acute severe ulcerative colitis (ASUC). We investigated prospectively the impact of rescue therapy on timing and postoperative complications of urgent colectomy and subsequent restorative surgery for steroid refractory ASUC. METHOD: All consecutive presentations of steroid refractory ASUC at the Royal Brisbane Hospital (1996-2009) were entered in the study. Data collated included demographics, clinical and laboratory parameters on admission, medical therapy and operative and postoperative details. Steroid refractory ASUC patients undergoing immediate colectomy were compared with those failing rescue therapy and requiring same admission colectomy. RESULTS: Of 108 steroid refractory ASUC presentations, 19 (18%) received intravenous steroids only and proceeded directly to colectomy. Rescue medical therapy was instituted in 89 (82%) patients with 30 (34%) failing to respond and proceeding to colectomy. There was no significant difference in the median time from admission to colectomy for rescue therapy compared with steroid-only cases (12 vs 10 days, P = 0.70) or 30-day complication rates (27%vs 47%, P = 0.22). The interval from colectomy to a subsequent restorative procedure was significantly longer for patients who failed rescue therapy (12 vs 5 months, P = 0.02). Furthermore 30-day complications following pouch surgery were significantly higher in patients who failed rescue therapy (32%vs 0%, P = 0.01). CONCLUSION: Rescue therapy in steroid refractory ASUC is not related to delay in urgent colectomy or increased post-colectomy complications.

The ideal ileal-pouch design: a long-term randomized control trial of J- vs W-pouch construction.

BACKGROUND: The IPAA has become established as the preferred technique for restoring intestinal continuity postproctocolectomy. The ideal pouch design has not been established. W-pouches may give better functional results owing to increased volume, whereas the J-pouch's advantage is its straightforward construction. We report short- and long-term results of an randomized control trial designed to establish the ideal pouch. DESIGN: Ninety-four patients were randomly assigned to J- and W-pouches (49:45) and assessed at 1 and 8.7 years postoperatively. Assessment was questionnaire based and designed to assess pouch function and patient quality of life. RESULTS: Eighty-five percent of patients were followed up at 1 year, and 68% were followed up at 8.7 years. At 1 year, there was a significant difference in 24-hour bowel movement frequency J- vs W-pouches 7 vs 5(p < 0.001) and in daytime frequency J- vs W-pouches 6 vs 4 (p < 0.001), with no difference in nocturnal function. At 9-year follow-up, function had equilibrated between the 2 groups: 24-hour bowel movement frequency J- vs W-pouches 6.5 vs 6 (p = 0.36), daytime frequency 5.5 vs 5 (p = 0.233), and nocturnal function 1 vs 1 (p = 0.987). Mean operating time of J- and W-pouches was 195 and 215 minutes (p < 0.05). All other parameters, pad usage, urgency, incontinence, and quality of life, did not differ significantly between groups. CONCLUSION: These data demonstrate that the theoretical functional advantage conferred on the W-pouch by its greater volume exists only in the short term and is of little consequence to patients' long-term quality of life. This advantage is attenuated as the pouches mature, resulting in no disparity in pouch function. This, combined with the more consistent, efficient, and easily taught construction of the J-pouch, should conclusively establish it as the optimum ileal-pouch design.

The relationship between milk production and farm-gate nitrogen surplus for the Waikato region, New Zealand.

As the scope and scale of New Zealand (NZ) dairy farming increases, farmers and the industry are being challenged by Government and the New Zealand public to address growing environmental concerns. Dairying has come under increasing scrutiny from local authorities tasked with sustainable resource management. Despite recent efforts of farmers and industry to improve resource use efficiency, there is increasing likelihood of further regulatory constraints on water use and nutrient management. This study uses available data on farm-gate nitrogen (N) surpluses and milk production from the Waikato, New Zealand's largest dairying region, together with a farm scale modeling exercise, to provide a perspective on the current situation compared to dairy farms in Europe. It also aims to provide relevant guidelines for N surpluses and efficiencies under NZ conditions. Waikato dairy farms compare favorably with farms in Europe in terms of N use efficiency expressed as L milk/kg farm-gate N surplus. Achievable and realistic good practice objectives for Waikato dairy farmers could be 15,000 L milk/ha (1200 kg milk fat plus protein/ha) with a farm-gate N surplus of 100 kg/ha giving an eco-efficiency (L milk/kg N surplus) of 150, and long-term average nitrate leaching losses of approximately 25-30 kg/ha/yr. This can be achieved by increasing the N conversion efficiency through lower replacement rates (16 versus 22%), lower stocked (< 3 cows/ha) high genetic merit cows (30 L milk/day at peak) milked for longer (277 versus 240 days), feeding effluent-irrigated, home-grown, low-protein supplements to cows on high-protein, grass-clover pastures to dilute N concentration in the diet, removing some of the urinary N from the paddocks during critical times by standing cows on a loafing pad for part of the day, and through lower N fertilizer rates (50-70 kg/ha/yr compared to the norm of 170-200 kg/ha/yr) and using a nitrification inhibitor and gibberellins to boost pasture growth and the former to reduce N leaching.

Laparoscopic resection of advanced colorectal cancer.

BACKGROUND: Palliative resection of the primary tumour in asymptomatic patients with stage IV colorectal cancer is associated with improved survival and fewer complications. Laparoscopic surgery is widely employed in the curative treatment of colorectal cancer, but its value in advanced colorectal cancer remains unclear. METHODS: All patients who underwent laparoscopic resection of primary colorectal cancer in this unit between June 1991 and Jan 2010 were entered into a prospective computerized database. Outcomes for patients with laparoscopic resection of stage IV colorectal cancer were compared with those of patients who had laparoscopic surgery for stage I disease. RESULTS: Some 185 patients with stage IV colorectal cancer who underwent laparoscopic resection were compared with 310 patients who had stage I colorectal cancer. Some 94·1 and 98·4 per cent of operations respectively were completed laparoscopically. Hospital stay was slightly longer in the group with stage IV disease (mean 6·2 versus 5·3 days; P = 0·091). The 30-day mortality rate was 2·7 per cent in patients with stage IV disease and 0·6 per cent in those with stage I tumours (P = 0·061). There was no difference in complications. One-year survival rates were 77·8 and 99·0 per cent respectively (P < 0·001). CONCLUSION: Short-term outcomes after laparoscopic surgery for stage IV colorectal cancer in selected patients are equivalent to those for stage I cancers.

The prothrombinase activity of FGL2 contributes to the pathogenesis of experimental arthritis.

OBJECTIVE: Fibrin deposition is integral to the pathogenesis of collagen-induced arthritis (CIA), an experimental model of rheumatoid arthritis (RA). Membrane-associated fibrinogen-like protein 2 (mFGL2), a novel inducible prothrombinase, generates fibrin by an alternate pathway and has been reported to be involved in the pathogenesis of a number of immune-mediated diseases. We hypothesized that expression of mFGL2 in inflamed synovium contributes to the fibrin deposition and subsequent inflammation in arthritis. METHODS: DBA/1 mice were immunized with 100 µg bovine collagen type II (CII) emulsified in complete Freund's adjuvant (CFA) followed by lipopolysaccharide (LPS) injection. Expression of mFGL2 prothrombinase in association with fibrin deposition was examined in mice with CIA and CD200-treated mice following induction of CIA. To directly assess the contribution of mFGL2, fgl2(-/-) mice were injected with antibody to CII (anti-CII). RESULTS: Levels of fgl2 mRNA transcripts and mFGL2 protein were markedly up-regulated in joints of mice that developed CIA. Fibrin deposition was prominent within the synovial lining and articular joint space associated with expression of mFGL2. Inhibition of CIA by the immunosuppressant CD200 was associated with decreased expression of fgl2 mRNA and mFGL2 protein and absence of fibrin deposition. Following injection of anti-CII, all fgl2(+/+) mice developed severe arthritis with clinical and histological manifestations characteristic of RA, whereas fgl2(-/-) mice failed to develop any clinical manifestation or histological evidence of arthritis. CONCLUSIONS: This study demonstrates that the prothrombinase activity of mFGL2 contributes to the pathogenesis of experimental arthritis. These studies may have therapeutic implications for patients with RA.

Nosocomial transmission of parainfluenza 3 virus in hematological patients characterized by molecular epidemiology.

We report an outbreak of parainfluenza 3 virus involving 17 hematology-oncology patients on 2 hospital wards. Sequence analysis of clinical samples confirmed homology of strains for 16/17 patients and 1 healthcare worker. Epidemiological analysis of the outbreak supported the molecular data with nosocomial transmission of the same genetic strain as the cause of the outbreak.

Effects of reduced frequency of milk removal on gene expression in the bovine mammary gland.

Regulation of milk synthesis and secretion is controlled mostly through local (intramammary) mechanisms. To gain insight into the molecular pathways comprising this response, an analysis of mammary gene expression was conducted in 12 lactating cows shifted from twice daily to once daily milking. Tissues were sampled by biopsy from adjacent mammary quarters of these animals during the two milking frequencies, allowing changes in gene expression to be assessed within each animal. Using bovine-specific, oligonucleotide arrays representing 21,495 unique transcripts, a range of differentially expressed genes were found as a result of less frequent milk removal, constituting transcripts and pathways related to apoptotic signaling (NF-kappaB, JUN, ATF3, IGFBP5, TNFSF12A) mechanical stress and epithelial tight junction synthesis (CYR61, CTGF, THBS1, CLDN4, CLDN8), and downregulated milk synthesis (LALBA, B4GALT1, UGP2, CSN2, GPAM, LPL). Quantitative real-time PCR was used to assess the expression of 13 genes in the study, and all 13 of these were correlated (P < 0.05) with values derived from array analysis. It can be concluded that the physiological changes that occur in the bovine mammary gland as a result of reduced milk removal frequency likely comprise the earliest stages of the involution response and that mechano-signal transduction cascades associated with udder distension may play a role in triggering these events.

Characteristics of natural killer cells in the murine intestinal epithelium and lamina propria.

Highly purified populations of lymphocytes were obtained from the murine intestinal mucosa using EDTA-collagenase isolation procedures in combination with discontinuous density centrifugation. Intraepithelial lymphocytes (IEL) were separated from lamina propria lymphocytes (LPL) and, within these two populations, fractions enriched or depleted in gut granular lymphocytes (gGL) were obtained. Using these cells in cytotoxic assays, it was shown that both IEL and LPL possess natural killer (NK) activity, and this was associated with gGL. The major effector cells of gut NK activity appeared to be Thy-1.2+, Lyt-1.1-, and Lyt-2.1-. The susceptibility of gut NK cells to anti-Thy-1.2 plus complement (C) was significantly higher than that of splenic NK cells. In contrast, anti-asialo GM1 and anti-NK-1.2 plus C only slightly affected the gut NK activity. Thus, the phenotype of the gut NK cells appears to be different from the splenic one and provides further evidence for NK heterogeneity and establishes the compartmentalization of one NK subpopulation. Beige mice, deficient in splenic NK activity, also had very low gut NK activity. W/Wv mice, which lack mast cell precursors, had normal numbers of gGL and diminished, but still present, gut and splenic NK activity. This deficiency did not segregate with the genes responsible for the basic hemopoietic stem cell defect, and these results argue against a close ontogenetic relationship between IEL, gGL, and intestinal mucosal mast cells. The relevance of these observations to the cell lineage of the effector cell of gut NK activity is discussed.

Amylase quantification in the terminal Ileum following formation of an Ileostomy.

Amylase is elevated in the foregut and has been used to confirm anastomotic integrity after pancreatic surgery. The physiological activity of pancreatic enzymes in the ileum has been studied in healthy volunteers but not quantitated with the simple and readily available amylase measurements employed with serum tests. We aim to quantitate the levels of amylase in the terminal ileum. This was a prospective, non-randomised, non-blinded, consecutive cohort study conducted at the Royal Brisbane and Women's Hospital. Consecutive patients undergoing routine surgery with an ileostomy were invited to participate in the study. Ileostomy effluent was collected and analysed daily for the first 5 post-operative days. This validation cohort included 8 males and 3 females, with a mean age of 49 years. Median daily amylase levels ranged from 4470 U/L to 23,000 U/L, with no specimens falling within the laboratory serum reference range of 40 to 130 U/L. Two specimens were not available on day one post-operative due to complete ileus. The sample size of 11 patients is small but was considered sufficient given that 55 effluent specimens were anticipated for analysis. Amylase levels remain highly elevated as the enzyme transits through the length of the small intestine and measured in the terminal ileum, and can be readily quantitated by the existing testing methodology routinely available.

Kinetics of maternally-derived serogroup A, C, Y and W-specific meningococcal immunoglobulin G in Malian women and infants.

A prospective, randomised, controlled observer-blind trial measuring the efficacy and immunogenicity of trivalent influenza vaccine (TIV) and the immunogenicity of quadrivalent meningococcal conjugate vaccine (MCV) in pregnant women and their infants up to 6 months of age was conducted in Mali. Here we reported the immunogenicity of MCV, which was used as a comparator vaccine to TIV, in this population. Third-trimester pregnant Malian women were randomized to receive TIV or MCV. Blood samples were collected from women prior to vaccination, 28 days post-vaccination, at delivery and 3 and 6 months post-delivery and from infants at birth and 3 and 6 months of age. Meningococcal-specific serogroup (Men) A, C, Y and W-specific antibodies were measured by enzyme linked immunosorbent assay in a randomly selected subset of 50 mother-infant pairs where the mother had received MCV. At birth, 94.0% (47/50) of infants had MenA specific IgG levels ≥ 2 µg/mL decreasing to 72.9% and 30.4% at 3 and 6 months of age. For MenC, 81.3% (39/48) of infants had MenC specific IgG levels ≥ 2 µg/mL at birth decreasing to 29.4% and 17.8% at 3 and 6 months of age. For MenY, 89.6% (43/48) of infants had MenY specific IgG levels ≥ 2 µg/mL at birth decreasing to 64.6% and 62.5% at 3 and 6 months of age. For MenW, 89.6% (43/48) of infants had MenW specific IgG levels ≥ 2 µg/ml at birth decreasing to 62.5% and 41.7% at 3 and 6 months of age. Maternal immunization with MCV conveyed protective levels of IgG at birth through to 3 months of age in the majority of infants.

Effect of using a stand-off pad on Campylobacter jejuni strain diversity in a herd of dairy cows.

AIM: To determine the effect of stand-off pad (SOP) use on the prevalence and strain diversity of Campylobacter jejuni in a small herd of dairy cows. METHODS AND RESULTS: Faecal samples were collected from 21 cows on four sampling occasions (events), one in each season, over 1 year. The cows usually grazed on pasture but during winter they spent 18 h a day on a SOP. Campylobacter prevalence ranged from 48-52% on pasture but was 62% on the SOP. The diversity of 386 C. jejuni isolates was determined using Enterobacterial Repetitive Intergenic Consensus polymerase chain reaction (ERIC/PCR). There were 11 ERIC types identified for the herd over the course of the study. Of those 11, four to seven (per event) were present when the cows were grazing pasture but only two during SOP use. CONCLUSIONS: The use of the SOP was associated with an increase in prevalence and a reduction in diversity of C. jejuni. SIGNIFICANCE AND IMPACT OF THE STUDY: The reduction in ERIC types on the SOP indicated an increase in transfer of only some strains of C. jejuni among the cows. One of these strains persisted throughout the study. The zoonotic potential of this strain warrants further investigation.

Eosinophils in chronically inflamed human upper airway tissues express transforming growth factor beta 1 gene (TGF beta 1).

Transforming growth factor beta (TGF beta) is a multifunctional protein which has been suggested to play a central role in the pathogenesis of chronic inflammation and fibrosis. Nasal polyposis is a condition affecting the upper airways characterized by the presence of chronic inflammation and varying degrees of fibrosis. To examine the potential role of TGF beta in the pathogenesis of this condition, we investigated gene expression and cytokine production in nasal polyp tissues as well as in the normal nasal mucosa. By Northern blot analysis using a porcine TGF beta 1 cDNA probe, we detected TGF beta 1-specific mRNA in nasal polyp tissues, as well as in the tissue from a patient with allergic rhinitis, but not in the normal nasal mucosa. By the combination of tissue section staining with chromotrope 2R with in situ hybridization using the same TGF beta 1 probe, we found that approximately 50% of the eosinophils infiltrating the polyp tissue express the TGF beta 1 gene. In addition, immunohistochemical localization of TGF beta 1 was detected associated with extracellular matrix as well as in cells in the stroma. These results suggest that in nasal polyposis where eosinophils are the most prevalent inflammatory cell, TGF beta 1 synthesized by these cells may contribute to the structural abnormalities such as stromal fibrosis and basement membrane thickening which characterize this disease.

Transmission of integrated human herpesvirus-6 in allogeneic hematopoietic stem cell transplantation.

Human herpesvirus 6 (HHV-6) viremia, as detected by polymerase chain amplification, occurs in approximately half of allogeneic hematopoietic stem cell transplant recipients. The significance of such viremia is incompletely understood, but HHV-6 encephalitis and bone marrow suppression are increasingly being recognized in patients with high viral DNA. We report two patients in whom donor-to-recipient transmission occurred through hematopoietic transplant by means of chromosomally integrated (CI) HHV-6. Iatrogenic transmission manifested at engraftment as asymptomatic elevation of HHV-6 viral DNA of 3600 and 15 400 DNA copies/ml in plasma and 6.1 x 10(6) and 9.7 x 10(5) DNA copies/ml in the whole blood. Both donors had elevated plasma HHV-6 PCR at 5.6 x 10(4) and 1.3 x 10(5) DNA copies/ml and strikingly elevated whole blood HHV-6 levels at 4.1 x 10(6) and 4.7 x 10(6) DNA copies/ml, respectively. CI of the virus was traced to the mother of one patient and his donor. CI of HHV-6 may confound the interpretation of HHV-6 viremia after stem cell transplantation; consideration of the possibility of CI HHV-6 will avoid unnecessary antiviral therapy.

Milking cows once daily influences behavior and udder firmness at peak and mid lactation.

Our aim was to evaluate the effects of once-daily milking on the welfare of dairy cows in a pastoral-based farming system. There are concerns that cows milked only once daily may experience discomfort associated with udder distension. We evaluated the behavior, including lying time and postures, grazing patterns, and kicking behavior in the parlor, and measures of udder firmness in cows milked once daily in 2 experiments: 1) at peak lactation, comparing cows milked once (1x) or twice-daily (2x) from the time of calving (n = 4 groups; 1x and 2x treatments); and 2) during the transition from 2x to 1x milking at mid lactation (n = 12 groups; 1x, 2x, and 2x to 1x treatments or TRANS). At peak lactation, cows milked 1x were more likely to lie with their hind legs touching the body than cows milked 2x. There were no differences in udder firmness (1x: 10.0 vs. 2x: 9.9 +/- 0.13 g of force) or kicking (1x: 25 vs. 2x: 24 +/- 7.8%) behavior in the parlor. In the second experiment, milking frequency was reduced from 2x to 1x and this change resulted in an increase in udder firmness (1 x: 9.1, 2x: 9.3, and TRANS: 9.5 +/- 0.14 g of force). Despite these differences in udder firmness, lying time (1x: 10.1, 2x: 9.5, and TRANS: 9.6 +/- 0.38 h/24 h), postures, and concentrations of fecal glucocorticoid metabolites (1x: 10.0, 2x: 10.5, and TRANS: 10.4 +/- 0.49 ng/g of feces in the 3 d after transition) in cows milked 1x or 2x were similar. Although milking frequency did not influence total time spent grazing, the diurnal grazing pattern of cows milked 2x was disrupted by afternoon milking at both peak and mid lactation. Cows milked 2x were able to compensate for this by grazing more after the return to pasture (DIM 153 to 155, 1x: 52 vs. 2x: 66 +/- 6.2 min/90 min of grazing). Cows milked 1x had slightly longer strides than 2x cows at mid lactation (1x: 0.73, 2x: 0.70, and TRANS: 0.70 +/- 0.014 strides/m). In conclusion, under our experimental conditions, we found no overt changes in behavior or physiology to indicate that the welfare of cows milked 1x is impaired.

Trochleoplasty with a flexible osteochondral flap: results from an 11-year series of 214 cases.

AIMS: The Bereiter trochleoplasty has been used in our unit for 12 years to manage recurrent patellar instability in patients with severe trochlea dysplasia. The aim of this study was to document the outcome of a large consecutive cohort of patients who have undergone this operation. PATIENTS AND METHODS: Between June 2002 and August 2013, 214 consecutive trochleoplasties were carried out in 185 patients. There were 133 women and 52 men with a mean age of 21.3 years (14 to 38). All patients were offered yearly clinical and radiological follow-up. They completed the following patient reported outcome scores (PROMs): International Knee Documentation Committee subjective scale, the Kujala score, the Western Ontario and McMaster Universities Arthritis Index score and the short-form (SF)-12. RESULTS: Outcomes were available for 199 trochleoplasties in 173 patients giving a 93% follow-up rate at a mean of 4.43 years (1 to 12). There were no infections or deep vein thromboses. In total, 16 patients reported further patella dislocation, giving an 8.3% rate of recurrence. There were 27 re-operations, giving a rate of re-operation of 14%. Overall, 88% were satisfied with the operation and 90% felt that their symptoms had been improved. CONCLUSION: All PROMs improved significantly post-operatively except for the mental component score of the SF-12. Trochleoplasty performed using a flexible osteochondral flap is an effective treatment for recurrent patellar instability in patients with severe trochlea dysplasia and gives good results in the medium term. Cite this article: Bone Joint J 2017;99-B:344-50.

A systems comparison of once- versus twice-daily milking of pastured dairy cows.

The objective of this study was to compare the effect of milking frequency (once vs. twice-daily milking) and breed (Holstein-Friesians vs. Jerseys) on milk and milk solids (MS; milk fat + milk protein), yield per cow, milk composition, somatic cell count and lactation length; cow body weight, body condition score, and reproductive performance over a 4-yr period. Total cow numbers in each herd were 30, 35, 36, and 42 for Holstein-Friesians milked once or twice daily, and Jerseys milked once or twice daily, respectively. Forty hectares of pasture were subdivided into 4 smaller pastures of 10 ha each. Stocking rates for the once-daily herds were 16.7% greater than the twice-daily herd in their respective breed. An increased stocking rate was chosen to achieve equal milk and MS per ha from the 2 milking frequencies. Annual milk, fat, protein, and lactose yields per cow were less for once-daily than for twice-daily milking. Interactions were detected between milking frequency and breed for annual milk, fat, protein, and lactose yields per cow, because Jerseys were relatively less affected by once-daily than by twice-daily milking than Holstein-Friesians. Holstein-Friesian cows milked once daily produced 31.2% less milk and 29.4% less MS per cow than their twice-daily counterparts. In contrast, Jersey cows milked once daily produced 22.1% less milk and 19.9% less MS per cow than their twice-daily counterparts. Milk per ha was 17.7 and 9% less for the once-daily Holstein-Friesians and once-daily Jersey herds, respectively, compared with their twice-daily counterparts, because the greater stocking rate for the once-daily herds did not fully compensate for the milk loss per cow. Milking once daily increased somatic cell count throughout the year in both breeds. Cows milked once daily conceived 3 d earlier, took 5 d less from calving to conception, and needed 11% fewer controlled internal drug release devices than those milked twice daily. Milking once daily is a viable milking option for New Zealand farmers who are prepared to trade-off loss of MS income for increased time to accomplish other non-milking activities.

Yields and persistency of lactation in Friesian and Jersey cows milked once daily.

Effects of milking cows once daily throughout lactation at high stocking rates (17% more cows/ha than for those milked twice daily) were studied in 2 Friesian and 2 Jersey herds during 3 lactations. Cows were allocated to 2 herds within breed and were milked either once or twice daily, based on age, genetic merit, and previous performance. Cows remained in their original herd and were milked at the same milking frequency during all lactations. Culled cows (20% per year) were replaced by 2-yr-old heifers. Yields of milk, lactose, protein, and fat were measured every 2 wk by commercial herd test. Cubic splines (5 knots) were used to approximate the lactation curve for each cow-yr to provide estimates of performance for each day of lactation. Yields of milk were greater for Friesian and Jersey cows milked twice daily (4,751 +/- 89 and 3,067 +/- 81 kg/cow) than for cows milked once daily (3,329 +/- 80 and 2,431 +/- 75 kg/cow), respectively. Cows milked once daily had lesser total and peak yields of milk, lactose, protein, and fat than cows milked twice daily. Friesians had greater total and peak yields than Jerseys. Peak production for all milk components occurred earlier in lactation for cows milked once daily than twice daily (d 24 to 39 vs. 32 to 44). Three measures of persistency of lactation were considered for each cow with 2 measures (Pers1 and Pers2) indicating that cows milked twice daily had better persistency than those milked once daily. Ranking of herds in persistency tended to match the ranking based on total yields. Measures of persistency (Pers1 and Pers2) were positively related to total yield in the Jerseys milked once daily and negatively related to peak yield in the Friesians. The third persistency measure (Pers3) ranked once-daily Jerseys first and twice-daily Friesians last, and was negatively correlated with total yield in the Friesian herds and negatively correlated with peak yield in all herds. For most performance measures, cows milked twice daily had better total yields and persistency than cows milked once daily.

Sensitivity of human carcinoma cell lines to lysis by blood natural killer cells correlating with surface expression of carcinoembryonic antigen.

The HCT-8R clone of the HCT-8 human colon tumor line, which expresses increased quantities of carcinoembryonic antigen (CEA) on its surface, was discovered to have an enhanced susceptibility to lysis by natural killer (NK) cells in human peripheral blood. This increase in susceptibility to lysis by peripheral blood mononuclear cells was not explained by stimulation of interferon release by HCT-8R cells but rather was found to be attributable to an increased susceptibility of HCT-8R cells to lysis by those NK cells that bind to sheep erythrocytes (E-RFC). Cold target competition experiments and single-cell assay for cytotoxic cells suggested that the presence of surface CEA did not increase lysis of HCT-8R by facilitating "recognition" by E-RFC-type cytotoxic cells but by rendering HCT-8R cells more susceptible to the lytic mechanism of NK cells. The magnitude of expression of surface CEA by a variety of human carcinoma cell lines with a few exceptions and subclones of HCT-8 also correlated with increased susceptibility to lysis by blood mononuclear cells. The possible clinical significance of these findings was discussed.