Effect of nicotinic acid supplementation on digestion, metabolism, microbiome, and production in late-lactation Holstein cows.

The purpose of this experiment was to determine if nicotinic acid (NA) effects on dairy cows and rumen microbial characteristics are forage-type dependent (corn silage, CS; grass silage, GS). Four late-lactation (DIM = 225 ± 12 d) Holstein cows were used in a 4 × 4 Latin square design with a 2 × 2 factorial arrangement of treatments. The main effects were a CS (66.10% CS) based diet or a GS (79.59%) based diet with or without 12 g/d NA. Each experimental period lasted for 28 d. Milk production and milk components, blood metabolites, apparent total-tract nutrient digestibilities, minutes rumen pH were below 5.8 as an indicator of ruminal acidosis, and body temperature changes were analyzed as indicators of heat stress. Nicotinic acid supplementation did not improve apparent total-tract nutrient digestibility. Feeding a GS-based diet improved NDF and hemicellulose digestibility. Feeding a CS-based diet increased the apparent total-tract digestibility of fat, and minutes rumen pH below 5.8 for a greater proportion of the time. The CS-based diet also improved milk yield, milk fat and protein yields, and ECM yield; however, somatic cell count and BHB were also increased. Supplementing NA tended to decrease nonesterified fatty acids, especially when combined with GS where DMI was low. There was a trend for the total protozoa population to increase when GS and NA were fed but decreased when CS and NA were fed. Nicotinic acid tended to decrease rumen protozoal populations of Dasytricha, but increased populations of Ophryoscolex and Diplodiniinae with GS diets and decreased with CS diets. Entodiniinae were increased with CS but NA had no effect. Body temperature was increased when a CS-based diet was fed when compared with a GS-based diet. More research is needed to determine how NA can affect rumen microbial protein synthesis and what kind of diets will provide the optimum effect.

Production, milk fatty acid profile, and nutrient utilization in grazing dairy cows supplemented with ground flaxseed.

Flaxseed has been extensively used as a supplement for dairy cows because of its high concentrations of energy and the n-3 fatty acid (FA) cis-9,cis-12,cis-15 18:3. However, limited information is available regarding the effect of ground flaxseed on dry matter intake (DMI), ruminal fermentation, and nutrient utilization in grazing dairy cows. Twenty multiparous Jersey cows averaging (mean ± standard deviation) 111 ± 49 d in milk in the beginning of the study were used in a randomized complete block design to investigate the effects of supplementing herbage (i.e., grazed forage) with ground corn-soybean meal mix (control diet = CTRL) or ground flaxseed (flaxseed diet = FLX) on animal production, milk FA, ruminal metabolism, and nutrient digestibility. The study was conducted from June to September 2013, with data and sample collection taking place on wk 4, 8, 12, and 16. Cows were fed a diet formulated to yield a 60:40 forage-to-concentrate ratio consisting of (dry matter basis): 40% cool-season perennial herbage, 50% partial total mixed ration, and 10% of ground corn-soybean meal mix or 10% ground flaxseed. However, estimated herbage DMI averaged 5.59 kg/d or 34% of the total DMI. Significant treatment by week interactions were observed for milk and blood urea N, and several milk FA (e.g., trans-10 18:1). No significant differences between treatments were observed for herbage and total DMI, milk yield, feed efficiency, concentrations and yields of milk components, and urinary excretion of purine derivatives. Total-tract digestibility of organic matter decreased, whereas that of neutral detergent fiber increased with feeding FLX versus CTRL. No treatment effects were observed for ruminal concentrations of total volatile FA and NH3-N, and ruminal proportions of acetate and propionate. Ruminal butyrate tended to decrease, and the acetate-to-propionate ratio decreased in the FLX diet. Most saturated and unsaturated FA in milk fat were changed. Specifically, milk proportion of cis-9,cis-12,cis-15 18:3, Σn-3 FA, and Σ18C FA increased, whereas that of cis-9,cis-12 18:2, Σn-6 FA, Σ odd-chain FA, Σ<16C FA, and Σ16C FA decreased with feeding FLX versus the CTRL diet. In conclusion, feeding FLX did not change yields of milk and milk components, but increased milk n-3 FA. Therefore, costs and industry adoption of premiums for n-3-enriched milk will determine the adoption of ground flaxseed in pasture-based dairy farms.

Prepartum supplementation of nicotinic acid: Effects on health of the dam, colostrum quality, and acquisition of immunity in the calf.

Nicotinic acid (NA) has been shown to reduce lipolysis, alter milk components and the ruminal environment, and increase blood flow. Increased blood flow to the mammary gland during colostrogenesis might increase nutrients and immunoglobulin concentration of colostrum. Twenty-six multiparous Holstein cows were housed in a tiestall barn. Cows were blocked by expected calving date and randomly assigned to 1 of 2 treatments 4 wk prepartum: (1) 0g/d of NA (control, CON) or (2) 48g/d of NA (NA). Total mixed ration amounts fed and refused were measured daily to determine dry matter intake. Blood samples were collected from dams every Monday, Wednesday, and Friday from the coccygeal vein or artery and were analyzed for glucose, nonesterified fatty acids (NEFA), and ß-hydroxybutyrate (BHB). Colostrum was collected and weighed within 90 min of parturition. Colostral immunoglobulin G (IgG) concentration was analyzed using radial immunodiffusion assay. Calves were removed from their dams before suckling and weighed within 30 min after birth. Calves received 3 L of a lacteal-based colostrum replacer that provided a total of 225.8g of IgG within 2h of birth. Calf blood samples were collected via jugular venipuncture at 0 and 24h of age and analyzed for IgG concentration and determination of apparent efficiency of absorption. Colostrum yield, dry matter intake, IgG yield, and fat and solids percentage of colostrum did not differ between treatments. Serum concentrations of glucose and BHB were not affected by treatment. We detected an effect of week on serum glucose concentrations at calving and on serum BHB concentrations at 1 wk postpartum. There was a treatment by week effect for serum NEFA concentrations at 1 wk postpartum, where cows that received NA prepartum had higher serum NEFA concentration than CON cows, indicating that a NEFA rebound occurred. No differences were observed for calf body weight, 0- or 24-h serum IgG concentration, or apparent efficiency of absorption. Supplementation of NA increased IgG concentration in colostrum from 73.8 to 86.8g/L. Results indicate that 48g/d of supplemental NA during the prepartum period improved colostrum quality.

Cladding pumped few-mode EDFA for mode division multiplexed transmission.

We experimentally demonstrate a few-mode erbium doped fiber amplifier (FM-EDFA) supporting 6 spatial modes with a cladding pumped architecture. Average modal gains are measured to be >20dB between 1534nm-1565nm with a differential modal gain of ~3dB among the mode groups and noise figures of 6-7dB. The cladding pumped FM-EDFA offers a cost effective alternative to core-pumped variant as low cost, high power multimode pumps can be used, and offers performance, scalability and simplicity to FM-EDFA design.

Empirical evidence of alternative stable states in an estuary.

Due to human activity, ecosystems are exceeding their ecological thresholds and shifting into undesired alternative stable states with new ecological configurations. Despite their purported ubiquity, it is uncertain whether estuaries can exist in multiple stable states. We use data from a 3.5-year study of invertebrate communities in an Australian estuary that is usually closed to the ocean to test for their existence. Sampling spanned a 1.5-year period of hypersalinity (>40 ppt) during a prolonged estuary closure, where salinity reached 122 ppt, and for two years during and after the estuary opened to the ocean when salinities were mesohaline (5-19 ppt). Two distinct community states occurred before and after the sandbar breached, with an intermediary period of invertebrate community impoverishment due to sediment scouring. During the closure, the community was simple (average of one taxa 100 cm-2) and dominated by larvae of terrestrial insects, most notably the halotolerant, non-biting midge Tanytarsus barbitarsis. After opening, the richness and abundance of invertebrates increased (average of four taxa and 84 individuals 100 cm-2) as polychaetes, molluscs and crustaceans colonised the estuary, although recovery was incomplete according to previous species records. Duration of estuary closure and salinity were the strongest drivers of composition. This study, together with evidence from the literature, suggests a salinity threshold of 60-65 ppt between states. These empirical data meet key criteria of alternative states, i.e. a clear transition between two distinct self-sustaining communities, indicating a regime shift triggered by an exogenous event. Our findings suggest that temporarily open and closed estuaries can exist in alternative stable states, with prolonged closures, hypersalinity, and sandbar breaching being key determinants of the switch between states. This situation may apply to other low-inflow estuarine systems, particularly in arid, semi-arid, or seasonally arid climates, and may become more frequent with human-induced climate change.

Q-switched neodymium-doped Y3Al5O12-based silica fiber laser.

We present pulsed laser operation in a Nd-doped, Y3Al5O12-based silica fiber. The fiber was fabricated using the rod-in-tube technique with a Nd:YAG crystal rod as the core material and a silica tube for the cladding material. A spectroscopy study revealed that the core region had become amorphous in the process of fiber drawing. Q-switched pulsed laser operation was realized at a wavelength of 1058 nm when the fiber was cladding pumped at a wavelength of 808 nm. The laser delivered 38 µJ of energy in 65 ns pulses. The extracted energy was limited due to the multimodal operation of the fiber. Laser slope efficiency in continuous wave operation reached 52%. The spectroscopic properties of the fabricated fiber are discussed and compared to a Nd:YAG crystal and a Nd:Al-doped silica fiber.

Anti-tumour necrosis factor-alpha therapy for severe enteropathy in patients with common variable immunodeficiency (CVID).

We present three common variable immunodeficiency (CVID) patients with severe inflammatory bowel disease of unknown aetiology, resistant to steroid treatment, treated with infliximab. After exclusion of any infection, infliximab was given at a dose of 5 mg/kg every 4 weeks for a 3 month induction followed by every 4-8 weeks depending on clinical response. Two of these patients had predominantly small bowel disease; they both showed clinical response to infliximab with weight gain and improvement of quality of life scores. The third patient had large bowel involvement with profuse watery diarrhea; this patient improved dramatically within 48 hours of having infliximab treatment. All three patients have been maintained on infliximab treatment for between 5 and 53 months (mean 37 months) with no evidence of increased susceptibility to infections in the patients with small bowel disease, although the third patient developed two urinary tract infections and a herpes zoster infection following therapy. This is the first small case series to show that infliximab is a useful addition to current therapy in this rare group of patients with potentially life threatening enteritis.

Renal and gastrointestinal amyloidosis in an HIV-infected injection drug user.

A 30-year-old HIV-infected intravenous drug user presented with sepsis, acute renal failure, oedema, proteinuria and iron deficiency anaemia. After extensive investigation, a diagnosis of reactive systemic AA (amyloid, serum amyloid A protein) amyloidosis was made on the basis of renal, gastric and duodenal biopsies.

Immune reconstitution sarcoidosis presenting with hypercalcaemia and renal failure in HIV infection.

An HIV-positive white man developed hypercalcaemia and renal failure 15 months after starting highly active antiretroviral therapy. Investigations showed systemic sarcoidosis affecting parotids, skin and kidneys. This presentation was thought to be a manifestation of immune reconstitution inflammatory syndrome, and the patient was successfully treated with corticosteroid therapy.

Granular cell tumour of the bile duct mimicking distal cholangiocarcinoma: one case report and review of the literature.

Granular cell tumours (Gcts) are rare and most commonly located in the oral cavity, skin or subcutaneous tissue. The occurrence of this tumour in the biliary tract is rare. A 26 year old African man presented with abdominal pain and obstructive jaundice was found to have a localised distal bile stricture suggestive of cholangiocarcinoma which was resected by pylorus preserving partial pancreaticoduodenectomy. Histology revealed a gct of the intrapancreatic portion of the distal bile duct. GCT of the biliary tract are important as they are benign and can mimic bile duct cancers. A review of the 77 reported cases of Gcts of the biliary tract showed that the common bile duct is the most common site of occurrence (n=35). Only 2 cases in literature have been reported to be diagnosed preoperatively. Since there are no characteristic radiological features, the GCTs are difficult to differentiate from cholangiocarcinoma, sclerosing cholangitis or other benign tumors.

Obstructive jaundice secondary to neuroendocrine tumour in a patient with von Recklinghausen's disease.

Neurofibromatosis type 1 (NF1) is an autosomal dominant genetic disorder, with variable clinical manifestations and unpredictable course, associated with an increased incidence of various tumours. Plexiform neurofibromas are hallmark lesions of NF1; they are slow-growing tumours, which account for substantial morbidity, including disfigurement and functional impairment, and may even be life-threatening. Neuroendocrine tumours (NETs), a rare diverse group of neoplasms, are occasionally associated with neurofibromatosis. Pancreatic NETs are tumours with an incidence of less than 1/100 000 population/year and complex patterns of behaviour, which often need complicated strategies for optimal management. We present the case of a young adult with NF1, having a unique concurrence of plexiform neurofibroma involving the liver with an ampullary NET, and we discuss step by step the management in a specialist centre.

Natural history of hepatitis B in perinatally infected carriers.

OBJECTIVES: To establish natural seroconversion rates and incidence of hepatic pathology in perinatally infected hepatitis B carriers. METHODS: Seventy three perinatally infected hepatitis B carriers identified through maternal screening were evaluated. Fifty three were born to parents from the Indian subcontinent, nine were Oriental, six were Afro-Caribbean, and five were white. Median follow up was 10.24 (range 2.02-20.16) years. RESULTS: Only three of the children followed up had cleared hepatitis B surface antigen during this period, and 30% of the children had seroconverted to anti-HBe. Seroconversions to anti-HBe were observed in Asian (18/50) and white (4/5) children, but not in Oriental or Afro-Caribbean children. More girls (40%) than boys (23%) had seroconverted, but the difference was not significant. All children were asymptomatic with normal physical examination, growth, and development. Almost half (48%) of the hepatitis B e antigen (HBeAg) positive children had normal hepatic transaminases and liver function. Thirty five liver biopsies were performed in children with active virus replication (HBeAg or hepatitis B virus DNA positive) who were being considered for antiviral treatment as part of a clinical trial and were scored using the Ishak method. Two thirds (62%) of the children had mild hepatitis, 60% had mild fibrosis, and 18% had moderate to severe fibrosis. There was a weak correlation between histological evidence of hepatitis and hepatic transaminase activity, implying that biochemical monitoring of hepatic disease activity may be ineffective. CONCLUSIONS: These asymptomatic hepatitis B virus carrier children remain infectious in the medium to long term with notable liver pathology. They should receive antiviral treatment to reduce infectivity and to prevent further progression of liver disease. Hepatic transaminases alone are not a reliable marker of liver pathology, and liver histology is essential before consideration for antiviral treatment.

Numerical evidence for divergent Burnett coefficients.

In previous papers [Phys. Rev. A 41, 4501 (1990); Phys. Rev. E 18, 3178 (1993)], simple equilibrium expressions were obtained for nonlinear Burnett coefficients. A preliminary calculation of a 32-particle Lennard-Jones fluid was presented in the previous papers. Now, sufficient resources have become available to address the question of whether nonlinear Burnett coefficients are finite for soft spheres. The hard sphere case is known to have infinite nonlinear Burnett coefficients (i.e., a nonanalytic constitutive relation) from mode-coupling theory. This paper reports a molecular dynamics caclulation of the third order nonlinear Burnett coefficient of a Lennard-Jones fluid undergoing color flow, which indicates that this term diverges in the thermodynamic limit.

Preparing the P & T committee agenda for new drug requests.

Preparing an agenda is an important element in conducting an effective P & T Committee meeting. A key responsibility of P & T Committee members is reviewing the rationale for formulary requests. Therefore, it is generally an agenda item. This article describes a process for planning, preparing, and distributing agenda materials for a committee meeting. A specific format and sequence for reviewing new drugs for formulary admission and criteria for selecting new drugs are discussed.

Mission, role, and functions of the P & T Committee.

This introductory article in a series on P & T Committees discusses the mission, role, and function of the committee in a hospital. With increasing complexity of drug therapy, the committee's mission has evolved into a multifaceted program related to promotion of rational and safe drug therapy within the institution. Components of the mission, the committee's responsibilities and functions, including formulary, policies and procedures, drug utilization review, drug administration, investigational drug studies, and education, are introduced and briefly discussed in terms of their role in the institution, accreditation standards, and published standards of practice. Future articles will provide fuller consideration of these topics.