Effects of enzyme supplementation on performance, nutrient digestibility, gastrointestinal morphology, and volatile fatty acid profiles in the hindgut of broilers fed wheat-based diets

A growth trial and a metabolism trial were conducted as 2 experiments to investigate the effects of dietary enzyme supplementation (primarily xylanase and beta-glucanase) on performance, nutrient digestibility, intestinal morphology, digestive organ size, and volatile fatty acid profiles in the hindgut of broiler chickens fed wheat-based diets. The experimental diets in both trials consisted of a wheat-based control diet supplemented with 0, 200, 400, 600, 800, or 1,000 mg/kg enzyme. Diets were given to the birds from d 7 to 42 of age. In the growth trial, enzyme supplementation improved performance of the broilers; daily gain and feed conversion increased linearly (P < 0.01) with increasing levels of enzyme supplementation. Enzyme inclusion decreased the size of the digestive organs and the gastrointestinal tract to some extent. The relative length of each intestinal segment decreased linearly (P < 0.05). The relative weight of the anterior intestine on d 21 and ileum on d 42 also decreased linearly (P < 0.01). On d 21 and 42, there were negative linear (P < 0.05) relationships between increasing enzyme supplementation and the relative weight of the liver and pancreas, respectively. Furthermore, there was a linear (P < 0.01) increase in total volatile fatty acid content in ileum on d 21 and in the cecum on d 21 and 42. During each period of the metabolism trial, apparent crude protein digestibility increased linearly (P < 0.05), whereas no differences were detected (P > 0.05) in AME.

Effects of dietary conjugated linoleic acid on the productivity of laying hens and egg quality during refrigerated storage

Five hundred and four 40-wk-old Brown Dwarf hens (1.51 +/- 0.08 kg BW) were fed corn-soybean meal diets containing 0, 1, 2, 3, 4, 5, or 6% conjugated linoleic acid (CLA) for 56 d to measure the effects of dietary CLA on laying hen productivity and egg quality during refrigerated storage. Four hens were placed in 1 cage, and 3 cages were grouped as 1 replicate resulting in 6 replicates per treatment. After feeding the experimental diets for 11 d, eggs were collected to determine the fatty acid composition of egg yolks. From d 12 to 18, eggs from hens fed diets containing 0, 2, 4, and 6% CLA diets were stored at 4 degrees C for up to 28 d. At designated times (1, 14, or 28 d), eggs were taken, broken, and shelled to evaluate water content, pH, and ion concentration. Firmness of hard-cooked egg yolk was also determined. With increased dietary CLA, feed intake, BW gain, rate of egg production, egg weight, and feed efficiency all decreased linearly (P < 0.01). The weight of the yolk, albumen, and shell decreased linearly (P < 0.01) with increasing dietary CLA. Concentration of CLA in the yolk lipids increased quadratically (P < 0.01), with increasing dietary CLA. Concurrent increases (P < 0.01) in the concentration of myristic, palmitic, and stearic acids and decreases (P < 0.01) in oleic, linoleic, linolenic, and archidonic acids in egg yolk lipids were observed. Days of storage and CLA (P < 0.01) increased yolk firmness. Egg yolk water content and pH increased with storage and CLA content (P < 0.01). Corresponding decreases were observed in albumen pH. Regardless of dietary treatment, the concentrations of Na, K, and Mg in egg yolks increased with longer storage time. At 28 d of storage, there was a linear (P < 0.01) increase in Na, K, and Mg content in egg yolks as dietary CLA increased. In contrast to the egg yolk, the concentrations of Na, K, and Mg in egg albumen decreased with storage time. On d 28, there was a linear decrease (P < 0.01) in the Na content of albumen with increasing CLA. This study suggests that the greater firmness of CLA-fed eggs might be related to the change of pH, water content, and ion concentrations during refrigerated storage.

Influence of cultivating conditions on the alpha-galactosidase biosynthesis from a novel strain of Penicillium sp. in solid-state fermentation

AIMS

The work is intended to achieve optimum culture conditions of alpha-galactosidase production by a mutant strain Penicillium sp. in solid-state fermentation (SSF).

METHODS AND RESULTS

Certain fermentation parameters involving incubation temperature, moisture content, initial pH value, inoculum and load size of medium, and incubation time were investigated separately. The optimal temperature and moisture level for alpha-galactosidase biosynthesis was found to be 30 degrees C and 50%, respectively. The range of pH 5.5-6.5 was favourable. About 40-50 g of medium in 250-ml flask and inoculum over 1.0 x 10(6) spores were suitable for enzyme production. Seventy-five hours of incubation was enough for maximum alpha-galactosidase production. Substrate as wheat bran supplemented with soyabean meal and beet pulp markedly improved the enzyme yield in trays.

CONCLUSIONS

Under optimum culture conditions, the alpha-galactosidase activity from Penicillium sp. MAFIC-6 indicated 185.2 U g(-1) in tray of SSF.

SIGNIFICANT AND IMPACT OF THE STUDY

The process on alpha-galactosidase production in laboratory scale may have a potentiality of scaling-up.

In vitro fermentation of various fiber and starch sources by pig fecal inocula1

Freeze-dried ileal effluent (1% wt/vol) from cannulated pigs fed rice-based diets with the inclusion of either animal protein (CON), animal protein plus potato starch (PS), animal protein plus sugar beet pulp (SBP), or animal protein plus wheat bran (WB) was incubated anaerobically at pH 6.0 in fermenters containing 5% (wt/vol) fecal slurry comprising mineral salts medium and 50 g/L of fresh feces from pigs fed the same diets as the cannulated pigs. Samples were collected from the fermenters at 0, 2, 4, 12, 24, and 48 h during in vitro fermentation for measuring nonstarch polysaccharides (NSP), starch, and short-chain fatty acids (SCFA). Results showed that the major SCFA produced were acetate, propionate, and butyrate. The inclusion of soluble dietary fiber (diet SBP) caused the highest concentrations of acetate, propionate, butyrate, and total SCFA, whereas the increase in the production of propionate resulting from the addition of insoluble dietary fiber (diet WB) only occurred at the initial stages during 48 h in vitro fermentation. At all sampling occasions (except for 4 h), the levels of butyrate were increased (P < 0.01) by resistant starch compared with fiber sources, showing that a higher level of butyrate can be achieved through microbial fermentation by potato starch. Lowered (P < 0.05) butyrate concentrations were observed with diet WB during in vitro fermentation. With the inclusion of fiber sources, the energy originating from SCFA was similar to that from NSP disappearance, whereas the values were lower (P < 0.05) from NSP disappearance than for SCFA generated without fiber sources supplemented. We conclude that more substrate is available in ileal effluent with the addition of soluble dietary fiber, and an increased level of butyrate could be achieved through microbial fermentation by resistant starch.

True amino acid availability in chinese high-oil corn varieties determined in two types of chickens

True amino acid availability (TAAA) was determined in conventional corn (CC) and in 2 Chinese high-oil corn varieties (CHOC1; CHOC2). The CC, CHOC1, and CHOC2 contained 3.7, 6.6, and 7.5% oil (ether extract) on a dry matter basis, respectively. The CP content (% dry matter) of the corn increased from 8.6 to 12.2% as oil increased from 3.7 to 7.5%. Birds (Hy-Line roosters or Arbor Acres broilers) were given 1 of the 3 corn varieties as the sole dietary ingredient in a conventional (intubation method) TAAA assay. There was a significant (P < 0.05) effect of bird type on gut metabolic (endogenous) amino acid excretion values with the broilers having higher excretions. For all amino acids, there was also a significant (P < 0.05) effect of bird type on TAAA with the Hy-Line roosters having higher TAAA values. The mean value for TAAA calculated over all of the amino acids showed a 9.8% unit higher digestibility for roosters compared with the broilers. Differences in TAAA between the corn varieties were statistically significant for alanine and valine only. Overall, the present results indicate that TAAA is equal to or superior to that in CC and that the TAAA content is higher in CHOC compared with CC. Bird type has an important effect on TAAA results and should be considered when developing TAAA assays and interpreting TAAA values.

Apparent ileal digestibility of amino acids and the digestible and metabolizable energy content of high-oil corn varieties and its effects on growth performance of pigs

Two experiments were conducted to compare the nutritional value of normal and high-oil corn for pigs. The normal corn and the two varieties (high-oil corns A and B) of high-oil corn contained 4.41, 7.35 and 8.86% ether extract, on DM basis, respectively. In experiment 1, six non-littermate crossbred barrows (37.8 +/- 1.3 kg BW) were fitted with ileal T-cannulas and used in a double replicated Latin Square digestion trial. Three diets were formulated containing 96.6% of one of the three varieties of corn as the only protein source. Chromic oxide (0.4%) was added as a digestibility marker. Additional vitamins and minerals were added to meet requirements. The digestible energy concentrations for normal corn and high-oil corn A and B were 16.53, 16.99 and 17.07 MJ/kg while the metabolizable energy values were 15.82, 16.32 and 16.36 MJ/kg, on DM basis, respectively. The ileal amino acid digestibility of high-oil corn was generally higher than that of normal corn with significant differences being observed for the essential amino acids isoleucine and phenylalanine. In experiment 2, 96 pigs (8.01 +/- 0.14 kg BW) were used to evaluate four diets in a 2 x 2 factorial design conducted over a 35-day period. Corn variety (high-oil vs. normal corn) and nutrient density (high content of protein and ME vs. low content of protein and ME) were set as the two main effects. During the first 14 days, pigs fed high-oil corn diets consumed more feed and tended to get higher daily gain than pigs fed normal corn. Over the entire 35-day experiment, increasing dietary nutrient density increased daily gain and tended to increase feed conversion, while variety of corn had no significant effects on performance. Overall, the present results indicate that the energy concentration and ileal amino acid digestibility of high-oil corn varieties were equal or superior to those in normal corn and therefore they should be able to be effectively utilized in diets fed to swine.

Effects of fish oil supplementation on the performance and the immunological, adrenal, and somatotropic responses of weaned pigs after an Escherichia coli lipopolysaccharide challenge1

Seventy-two crossbred pigs (7.58 +/- 0.30 kg BW) weaned at 28 +/- 3 d of age were used to investigate the effects of fish oil supplementation on pig performance and on immunological, adrenal, and somatotropic responses following an Escherichia coli lipopolysaccharide (LPS) challenge in a 2 x 2 factorial design. The main factors consisted of diet (7% corn oil [CO] or 7% fish oil [FO]) and immunological challenge (LPS or saline). On d 14 and 21, pigs were injected intraperitoneally with either 200 microg/kg BW of LPS or an equivalent amount of sterile saline. Blood samples were collected 3 h after injection for analysis of interleukin-1beta (IL-1beta), prostaglandin E2 (PGE2), cortisol, growth hormone (GH), and insulin-like growth factor (IGF)-I. On d 2 after LPS challenge, peripheral blood lymphocyte proliferation (PBLP) was determined. Lipopolysaccharide challenge decreased ADG (487 vs. 586 g; P < 0.05) and ADFI (as-fed, 776 vs. 920 g; P < 0.05) from d 14 to 21 and ADG (587 vs. 652 g; P < 0.10) from d 21 to 28. Fish oil improved ADG (554 vs. 520 g; P < 0.10) and ADFI (891 vs. 805 g; P < 0.10) from d 14 to 21. On d 14, LPS challenge x diet interactions were observed for IL-1beta (P < 0.10), PGE2 (P < 0.001), and cortisol (P < 0.05) such that these measurements responded to the LPS challenge to a lesser extent (IL-1beta: 93 vs. 114 pg/mL, P < 0.05; PGE2: 536 vs. 1,285 pg/mL, P < 0.001; cortisol: 143 vs. 206 ng/mL, P < 0.05) in pigs receiving the FO diet than in pigs fed the CO diet. In contrast, among LPS-treated pigs, pigs fed the FO diet had higher IGF-I (155 vs. 101 ng/mL; P < 0.10) than those fed the CO diet. On d 21 among LPS-treated pigs, pigs fed FO had lower IL-1beta (70 vs. 84 pg/mL; P < 0.10) and cortisol (153 vs. 205 ng/mL; P < 0.05) than those fed CO. Pigs fed FO had lower PGE2 (331 vs. 444 pg/mL; P < 0.05) and higher IGF-I (202 vs. 171 ng/mL; P < 0.10) compared with those fed CO. Lipopolysaccharide challenge decreased GH (0.27 vs. 0.33 ng/mL; P < 0.05) on d 14, whereas it had no effect on GH on d 21. During both LPS challenge periods, the challenge increased PBLP when these cells were incubated with 8 (1.46 vs. 1.32; P < 0.10) or 16 microg/mL (1.46 vs. 1.30; P < 0.05) of concanavalin A. Fish oil had no effect on PBLP. These results suggest that FO alters the release of proinflammatory cytokines, which might lead to improved pig performance during an immunological challenge.

Comparisons of amino acid availability by different methods and metabolizable energy determination of a Chinese variety of high oil corn

TME, true amino acid availability (TAAA), AME, and apparent amino acid availability (AAAA) were determined in Chinese high oil corn (CHOC) and conventional corn (CC). The CC and CHOC contained 4.58 and 8.44% ether extract (DM basis), respectively. A precision-fed rooster assay was used in which each corn sample was tube-fed (50 g) to 16 roosters and excreta were collected for 48 h. A N-free diet and fasting methods were used to evaluate endogenous amino acid (AA) losses. Endogenous losses of 10 AA were different (P < 0.05) with the N-free and fasting methods; in most cases the mean value for the N-free treatment was greater (P < 0.05) than for the fasting treatment. The TME value for CHOC was greater than for CC (4,193 vs. 3,961 cal/g DM; P < 0.05). The true availability of aspartic acid, threonine, isoleucine, and leucine of CC and CHOC was higher (P < 0.05) for the N-free method than for the fasting method. When compared within the N-free or within the fasting method, the true availabilities of lysine, methionine, and proline were higher (P < 0.05) in CHOC than in CC, but the true availability of phenylalanine was lower (P < 0.05) in CHOC than in CC. The AAAA values, although lower, followed similar patterns as the TAAA values. The results of this study indicated that availability of AA in CHOC is equal or superior to that in CC and that the available energy for poultry is higher in CHOC than in CC.

Effects of lentinan on broiler splenocyte proliferation, interleukin-2 production, and signal transduction

Lentinan (LEN) is an intensively studied beta-glucan that has been shown to have immunostimulating and antitumor functions. However, it currently is not used in veterinary practice and animal production. This study was conducted to investigate the impacts of LEN on broiler splenocyte proliferation, interleukin-2 (IL-2) production, and to explore its effects on receptor signal transduction by determining signaling molecules, including nitric oxide (NO), cytosolic-free Ca2+, cytosolic cyclic adenosine monophosphate (cAMP), and cyclic guanosine monophosphate (cGMP). The results showed that compared to the control all three measured doses, including 40, 80, and 160 microg/mL LEN, increased splenocyte proliferation and IL-2 production (P < 0.05). Lentinan increased splenocyte NO production and cytosolic-free calcium concentration in a dose-dependent manner (P < 0.001). After incubating splenocytes for 20 min, LEN increased intracellular cAMP and cGMP concentrations at a dose of 80 and 160 microg/mL, respectively. However, after incubating the splenocytes for 60 min, LEN had no effect on cytosolic cAMP and cGMP concentration irrespective of the LEN dosage. Those results indicated that LEN had immunostimulatory effects on splenocytes by increasing splenocyte proliferation and IL-2 production and by activating splenocyte receptor signal transduction.

Effects of isomalto-oligosaccharides on broiler performance and intestinal microflora

Dose effects of dietary isomalto-oligosacchrides (IMO) on broiler growth performance and characteristics of the intestinal microflora were compared. Three hundred sixty male broilers were randomly allotted to five treatments, with eight replicate pens per treatment and nine chicks per pen. Chicks were fed either a basal diet (control) or the basal diet plus 0.3, 0.6, 0.9, or 1.2% IMO. All chicks had access to feed and water ad libitum during the 7-wk experiment. At the end of the experiment, eight chicks per treatment were randomly chosen to measure the thymus index. Additionally, six birds per treatment were randomly selected to determine viable bacterial counts of Lactobacillus, Escherichia coli, and total aerobes in the digestive tract. The digesta of all the killed birds were also used to measure short-chain fatty acid (SCFA) levels. The results indicate that IMO enhanced growth performance during the initial 3 wk, but no further effects were detected during the latter 4 wk of the experiment. Isobutyrate level in crop content and acetate level in duodenum digesta were decreased by supplementation with IMO (P < 0.05). Isovalerate level in duodenum digesta was decreased in the 0.3 and 0.6% IMO groups (P < 0.001), whereas the jejunum butyrate and isobutyrate levels of the 0.3% IMO group were higher than in other groups (P < 0.05). The facultative microflora of the crop and cecum were not affected by IMO supplementation. However, the thymus index was increased significantly in chicks consuming diets containing 0.3% IMO.

Effects of Chinese herbal polysaccharides on the immunity and growth performance of young broilers

Two trials were conducted to study the effects of two Chinese herbal polysaccharides [achyranthan (ACH), a low-molecular-weight polysaccharide, and astragalan (APS), a high-molecular-weight polysaccaride] on the immunity and growth performance of young broilers. Trial 1 was a 28-d growth assay, in which 7-d-old broilers (n = 240) were randomly allotted to one of three dietary treatments, with eight replicate pens per treatment and ten chickens per pen. Dietary treatments included a control corn-soy-fishmeal (Treatment 1), a diet with 200 mg/kg APS (Treatment 2), and a diet with 200 mg/kg ACH (Treatment 3). Blood samples were collected by cardiac puncture on Days 7, 14, 21, and 28 for determination of serum parameters, and chickens were killed on Day 28 to measure immune organ indexes. Trial 2 was an in vitro trial to study the effects of different concentrations of polysaccharides on broiler splenocyte functions. In Trial 1, feeding either APS or ACH had no significant effects on growth performance of broilers relative to the control. However, compared to the control, feeding ACH significantly increased microhemagglutination inhibition (HI) antibody titers, bursa of Fabricius index, serum albumin, serum calcium, and nitric oxide (NO) concentrations at Day 28 (P < or = 0.05). In Trial 2, both polysaccharides showed significant immunostimulating effects. They increased NO and interleukin-2 (IL-2) production of splenocytes and enhanced splenocyte proliferation in a dose-dependent manner (P < 0.05). Those results indicate that the immunostimulating effects of APS are not as pronounced as those of ACH. Achyranthan showed immunostimulating effects in both the growth assay and in vitro studies. Therefore, ACH may be a Chinese herbal polysaccharide that has the potential to be used as a feed additive to improve broilers' immunity.

Optimum ratio of histidine in the piglet ideal protein model and its effects on the body metabolism. II. Optimum ratio of histidine in 10-20 KG piglet ideal protein and its effects on blood parameters

Two growth trails were conducted to determine the optimum ratio of histidine in 10-20 kg piglet ideal protein model. Four diets containing 0.23%, 0.31%, 0.39% and 0.47% digestible histidine (0, 0.08%, 0.16%, 0.24% crystalline histidine supplemented into the basal diet) were fed to 96 piglets of mean initial body weight 10.3 +/- 1.08 kg for 18 d in Experiment 1. Average daily gain, average daily feed intake and feed conversion efficiency were inhibited (P < 0.05) with the diet containing 0.23% digestible histidine. Performance was maximized with 0.31% digestible histidine. As the dietary histidine increased, blood urea nitrogen and serum cholesterol concentration were influenced significantly. The concentrations of serum histamine and free histidine did not change with increase in digestible histidine from 0.23 to 0.31%, but higher supplementation resulted in a significant linear increase in both serum parameters. It was concluded that the dietary level of 0.23% digestible histidine does not meet the requirement of 10-20 kg piglets. Based on the results from Experiment 1, Experiment 2 was designed to determine the optimum ratio of lysine:histidine in the ideal protein model of 10-20 kg piglet. Ninety-six Large White x Landrace piglets weighing 10.2 +/- 0.88 kg were divided into 4 groups. They were fed four diets containing 0.26, 0.29, 0.32 or 0.35% digestible histidine, formulated by adding 0.03, 0.06, 0.09 or 0.12% crystalline histidine to the basal diet. The trial lasted for 21 days. Results showed that performance was significantly improved with 0.32 and 0.35% digestible histidine. As dietary histidine increased, blood urea nitrogen tended to decrease but not significant at P < 0.05. Serum cholesterol concentration increased with an increase in dietary histidine level and reached a maximum at 0.35%. Serum histamine increased with increasing dietary histidine. Free serum histidine increased linearly with increased dietary histidine. From both experiments it was concluded that the digestible histidine requirement for 10-20 kg piglets was 0.31% and that the optimum ratio of dietary lysine to histidine should be 100:30. The concentrations of cholesterol, histamine and free histidine in serum were sensitive parameters to measure changes in dietary histidine levels.

Optimum ratio of histidine in the piglet ideal protein model and its effects on body metabolism. I. Basal diet formulation based on digestible amino acids according to the ideal protein model for 10 to 20 kg piglets

A 4 x 4 Latin square design was used to determine ileal apparent digestibility of amino acids (AAs) in corn, soybean meal, feather meal and dried whey in young pigs. The data were then to be used in formulating a basal diet for studies on AA metabolism in young pigs. Eight castrates T-cannulated at terminal ileum (average initial body weight 12.5 +/- 0.62 kg) were divided into 4 groups on the basis of body weight and transferred to individual metabolism crates. They were then fed four experimental diets containing the four feedstuffs to be tested (corn, soybean meal, feather meal and dried whey). The trial lasted 20 days, which included 4 five-day periods for ileal digesta collection. It was found that the digestibility of the AAs was similar to that reported in literature. Based on the findings a basal diet for this research was formulated according to an ideal protein model for the 10 to 20 kg piglet, on the basis of digestible AAs and containing 14.13 MJ/kg digestible energy, 18.22% crude protein, 1.04% digestible lysine and 0.23% digestible histidine.

[Establishment of detection test for hepatitis C virus antigen]

OBJECTIVE

To establish the enzyme linking immunosorbent assay (ELISA) test with the specific monoclonal antibody (McAb) for detecting the hepatitis C virus (HCV) antigen so as to study the possibility of HCV antigen detection from plasma and serum samples.

METHODS

Among the McAbs against HCV core and NS3 region, several kinds of combination models were analyzed to choose the optimal one. 348 samples from volunteer donors were tested by this test to calculate the cutoff value. 371 samples, among which 146 samples were positive to anti-HCV and 225 ones were negative to anti-HCV, were screened. The antigen positive samples were confirmed by HCV nested PCR.

RESULTS

The model of detection test was constructed with the C39,C7-6 as capture McAb and C39,C7-57 as HRP Conjugated McAb. This test could detect the C7 antigen to 5 ng/ml, and its cutoff value was determined as the average value of negative control by adding 0.25. Eleven of 146 samples positive to anti-HCV and 16 of 225 ones negative to anti-HCV were positive to HCV antigen. Among these 27 antigen positive samples, there were 23 positive to HCV RNA by PCR detection.

CONCLUSIONS

With this HCV antigen detection test, some of samples positive to HCV antigen can be found from plasma positive to and negative to anti-HCV and be confirmed by PCR. It is shown that it is possible to detect HCV antigen directly from plasma samples and it is important for HCV basic research and for control of transmission of HCV.

Binding site of Fe3+ at purine of ATP as studied by NMR

The binding site of Fe3+ in the purine base of adenosine 5'-triphosphate (ATP) was studied by nuclear magnetic resonance (NMR). The NMR relaxation rates (R1) of 1H and 31P in ATP solutions free of and containing ferric ions were measured in the pH range of 3-10. It was found that Fe3+ selectively enhanced the relaxation rate of protons. In the presence of Fe3+, the R1 of H2 was much bigger than that of H8 at a lower pH (3-4.5), while at a higher pH (5.5-7.5) the R1 of H8 was more enhanced than H2. At a pH of around 5, both H2 and H8, as well as all three phosphorous, showed a sudden jump in R1. When pH>8, Fe3+ failed to show appreciable enhancement of R1 to all protons and phosphorous. The quantitative data of relaxation rate enhancements suggest that the binding site of Fe3+ in ATP is strongly dependent on pH. At lower pH values, Fe3+ binds N1 but at higher pH it binds to N7. When pH is around 5, the whole purine base donates the aromatic pi-electrons to the ferric ion, forming a ferrocene-like complex, while when pH>8, ATP could not form complexes with Fe3+.

A multicentre study to investigate the prevalence of abnormal carbohydrate metabolism in Chinese pregnant women

OBJECTIVES

To determine the prevalence of abnormal carbohydrate metabolism in Chinese pregnant women. To study the inter-relationship between maternal body habitus, maternal serum glucose and birth weight of the baby.

METHODS

Multicentre observational study involving 713 pregnant Chinese women, attending antenatal clinics in Beijing, Shanghai, Guangzhou and Hong Kong.

RESULTS AND CONCLUSION

The overall prevalence of abnormal glucose tolerance was 6.9%. The prevalence was 6.8%, 5.5%, 7.2% and 8.1% in Beijing, Shanghai, Guangzhou and Hong Kong, respectively. The differences among the centres did not reach statistical significance (p = 0.9). The mean ponderal index of women with abnormal glucose tolerance was significantly higher than that of women with normal glucose tolerance (15.2 vs 14.3, p < 0.01). The birth weight ratio of the babies was positively correlated with the maternal height (correlation coefficient 0.23, 95% C.I. 0.15-0.30), weight (0.32, 95% C.I. 0.25-0.39) and to a lesser extent, the fasting level of serum glucose (0.10, 95% C.I. 0.02-0.28) but not with the 2 hour level of serum glucose.

Expression of insulin-like growth factor II in hepatitis B, cirrhosis and hepatocellular carcinoma: its relationship with hepatitis B virus antigen expression

Expression of insulin-like growth factor II in two human hepatocellular carcinoma cell lines and in hepatitis B, cirrhosis and hepatocellular carcinoma in 419 cases were investigated, and its relationship with the expression of hepatitis B virus X gene was studied by means of immunohistochemical and electron microscopic techniques. The results demonstrated that hepatocellular carcinoma cells (SMMC 7721 and QGY 7703) in culture could express insulin-like growth factor II. Expression seemed to be regulated by cell density, which was suggested as the molecular basis of the contact inhibition of cell proliferation. In tissue sections, cells with high expression of insulin-like growth factor II were observed not only in hepatocellular carcinoma (93%) but also in 95% of the pericancerous liver tissues, 72% of cirrhotic livers, 64% of chronic active hepatitis and 37% of chronic persistent hepatitis. In most cases of hepatocellular carcinoma, insulin-like growth factor II was localized in the cytoplasm of the cancer cells. In the benign liver disorders, four types of cells that highly expressed insulin-like growth factor II were observed: (a) a kind of small liver cell we named the small polygonal liver cell; (b) multinuclear giant hepatocytes; (c) hepatocytes in most of hyperplastic and neoplastic nodules, small hepatocyte nodules and some of regenerative nodules; and (d) some proliferating ductular cells. Even more interestingly, insulin-like growth factor II expression was shown to be closely related to the expression of hepatitis B virus X gene product. We suggest that the activation of insulin-like growth factor II gene and its overexpression may be a crucial step in the processes of hepatitis B virus-associated hepatocarcinogenesis and that the X gene product may activate the insulin-like growth factor II gene through a transactivation mechanism. In addition, we studied the characteristics of small polygonal liver cells, and the roles they may play in the regeneration and carcinogenesis of hepatitis B virus-infected liver are discussed.

Dermatofibroma: superficial fibrous proliferation with reactive histiocytes. A multiple immunostaining analysis

BACKGROUND

Dermatofibroma (DF) is a superficial form of benign fibrous histiocytoma, composed of a mixture of fibroblastic cells and histiocytic cells. The histogenesis of this lesion is a matter of controversy.

METHODS

Forty-five cases of DF were investigated by single and multiple immunostaining techniques, using panel of 12 antibodies including proliferating cell nuclear antigen (PCNA), vimentin, and macrophage/histiocyte markers (HAM56 and CD68).

RESULTS

Double immunostaining demonstrated that 58% of the DF cells simultaneously expressed PCNA and vimentin, whereas only 5% were PCNA+/HAM56+, and 2% were PCNA+/CD68+. By triple-stain for PCNA, vimentin, and HAM56, 56% of the DF cells were PCNA+/vimentin+/HAM56-, but only a few cells were PCNA+/HAM56+/vimentin+/-. Of the PCNA positive cells, 88% were vimentin+HAM56- and 10% were HAM56+ vimentin-/+. The cells positive for CD68 showed similar distribution to that of HAM56+ cells, though there were fewer of the former than the latter in most cases. These results suggest that the majority of the proliferating cells in DF express vimentin but not histiocytic markers. Morphologically, the PCNA+/vimentin+/HAM56- (or CD68-) cells exhibited a spindle-shaped configuration resembling fibroblasts, whereas most of the HAM56+/CD68+ cells possessed abundant rounded cytoplasm and were similar to normal histiocytes.

CONCLUSIONS

The present study suggests that the proliferative compartment of DF cells is composed chiefly of mesenchymal/fibroblastic lineage, accompanied by varying numbers of normal reactive histiocytes.