Changes in fermentation and biohydrogenation intermediates in continuous cultures fed low and high levels of fat with increasing rates of starch degradability.

Excessive levels of starch in diets for lactating dairy cattle is a known risk factor for milk fat depression, but little is known about how this risk is affected by differences in rates of starch degradability (Kd) in the rumen. The objective of this study was to compare accumulation of biohydrogenation intermediates causing milk fat depression, including conjugated linoleic acid (CLA), when corn with low or high Kd were fed to continuous cultures. Diets contained (dry matter basis) 50% forage (alfalfa pellets and grass hay) and 50% concentrate, with either no added fat (LF) or 3.3% added soybean oil (HF). Within both the LF and HF diets, 3 starch degradability treatments were obtained by varying the ratio of processed (heat and pressure treatments) and unprocessed corn sources, giving a total of 6 dietary treatments. Each diet was fed to dual-flow continuous fermenters 3 times a day at 0800, 1600, and 2400h. Diets were fed for four 10-d periods, with 7d for adaptation and 3d for sample collection. Orthogonal contrasts were used in the GLIMMIX procedure of SAS to test the effects of fat, starch degradability, and their interaction. Acetate and acetate:propionate were lower for HF than for LF but daily production of trans-10 18:1 and trans-10,cis-12 CLA were higher for HF than for LF. Increasing starch Kd from low to high increased culture pH, acetate, and valerate but decreased butyrate and isobutyrate. Changes in biohydrogenation intermediates (expressed as % of total isomers) from low to high starch Kd included reductions in trans-11 18:1 and cis-9,trans-11 CLA but increases in trans-10 18:1 and trans-10,cis-12 CLA. The results show that increasing the starch Kd in continuous cultures while holding starch level constant causes elevation of biohydrogenation intermediates linked to milk fat depression.

Serum cytokeratins in alcoholic liver disease: contrasting levels of cytokeratin-18 and cytokeratin-19.

Serum cytokeratin (CK) levels are widely used as tumor markers. Serum levels of CK-18, a tumor marker also known as tissue polypeptide specific antigen (TPS), are increased in patients with alcoholic liver disease. Cytokeratin-18 is the main component of Mallory bodies, a hallmark of alcoholic hepatitis, which may also contain CK-19. Serum levels of CK-18 and CK-19, a tumor marker also known as CYtokeratin FRAgment 21-1 (CYFRA 21-1) were investigated in (a) heavy drinkers with alcoholic liver disease (n=15), (b) patients with malignancy (n=22), and (c) healthy controls (n=10). Serum levels of CYFRA 21-1 (CK-19) were markedly increased in patients with malignancy, but were similar in heavy drinkers and healthy controls. In contrast, serum levels of TPS (CK-18) in heavy drinkers were higher than those of healthy controls, and even tended to be higher than those of patients with malignancy. Both CK-19 and CK-18 levels were higher in cases of alcoholic hepatitis than in cases of fatty liver. Correlation with hepatocyte CK inclusions was stronger for serum TPS (CK-18) than for CYFRA 21-1 (CK-19). In conclusion, serum CYFRA 21-1 (CK-19) and TPS (CK-18) show a different pattern of increase that could reflect the composition of the altered hepatocyte CK network in alcoholic liver disease. Their usefulness as tumor markers, particularly that of serum TPS (CK-18), may be limited in patients with alcoholic liver disease.

Serum immunoglobulins (IgG, IgA, IgM) in chronic hepatitis C. A comparison with non-cirrhotic alcoholic liver disease.

BACKGROUND/AIMS: Serum immunoglobulin concentrations are commonly elevated in patients with liver cirrhosis. Immunoglobulin class increase may vary depending on the cause of liver disease. Hepatitis C virus is, together with alcohol, a leading cause of chronic liver disease. The present study aimed to evaluate serum IgG, IgA and IgM levels in chronic hepatitis C. Results were compared with those of patients with non-cirrhotic alcoholic liver disease and healthy controls. Special attention was given to cases with minimal liver disease, as an approach to evaluate if the causing agent, independently of liver damage, influences serum immunoglobulin levels. METHODOLOGY: A total of 274 patients with histologically-proven chronic hepatitis C, 121 alcoholics with non-cirrhotic liver disease (steatosis or alcoholic hepatitis), and 75 healthy controls were studied. Serum IgG, IgA, and IgM were assayed by nephelometry. RESULTS: Serum IgG was increased in patients with chronic hepatitis C with respect to both alcoholics (p < 0.001) and healthy controls (p < 0.001). IgG levels were similar in alcoholics and in controls. IgA was increased in patients with non-cirrhotic alcoholic liver disease with respect to both chronic hepatitis C patients (p < 0.001) and controls (p < 0.001). IgA values were similar in subjects with chronic hepatitis C and controls. Selective IgG or IgA alteration was present in cases with minimal liver disease (chronic hepatitis C with a Knodell index equal or lower than 3, and alcoholics with liver steatosis, respectively). CONCLUSIONS: Hepatitis C virus and alcohol are linked to a selective increase of serum IgG and IgA, respectively, even in cases with mild or minimal liver disease.

Total serum IgE levels in chronic hepatitis C: influence of interferon alpha therapy.

BACKGROUND: Liver disease has been considered a prominent cause of IgE elevation. No data on serum IgE levels in chronic hepatitis C have been reported. Interferon-alpha is a standard therapy for chronic hepatitis C. Cytokine use is a promising type of immunomodulation in the treatment of IgE-mediated diseases. The effects of interferon-alpha therapy on serum IgE have not been fully evaluated. The aim of the study was to evaluate both serum IgE levels in patients with chronic hepatitis C and the course of these levels after interferon-alpha therapy. PATIENTS AND METHODS: Serum IgE was determined in 100 adult patients with chronic hepatitis C (24 atopics according to positive skin prick tests and 76 nonatopics) and in 75 healthy controls (25 atopics and 50 nonatopics). Serum IgE measurements were repeated at 1 and 3 months of therapy with recombinant interferon-alpha (3 x 106 units s.c. 3 times weekly) in 34 of these patients. RESULTS: Serum IgE levels were similar in chronic hepatitis C patients and in controls when adjusted for atopic status. Among patients with chronic hepatitis C, serum IgE levels were unrelated to liver necroinflammatory activity. A modest but statistically significant increase of IgE values was observed after interferon-alpha therapy, particularly in patients with no virological response. CONCLUSIONS: Chronic hepatitis C is not a significant cause of increased total serum IgE values. Serum IgE increase in some patients with liver disease may be related to the cause of liver injury and not to liver disease per se. Interferon-alpha therapy in patients with chronic hepatitis C is followed by no modification or even a moderate increase of serum IgE values.