Response to selection for litter size in Danish Landrace pigs: a Bayesian analysis

A replicated selection experiment aimed at increasing litter size (total number of pigs born per litter) in Danish Landrace pigs was conducted from 1984 to 1991. The experiment included two selection and two control lines. In each generation, 30 and 14 first litters were produced in selection and control lines, respectively, and dams produced two litters. Each replicate, consisting of one selection and one control line, was founded from 60 families chosen randomly from the population at large. Family selection was practiced, and the criterion was the predicted breeding value for litter size computed using a repeatability animal model, and taking into account all available information. The data consisted of 947 records from 523 dams (424 dams had two litters) representing five cycles of selection of increased litter size. Data were analyzed from a Bayesian perspective, based on marginal posterior distributions of genetic parameters of interest. Marginalization was achieved using Gibbs sampling, with a single chain length of 1 205 000. After discarding the first 5 000 iterations, a sample was drawn every ten iterations, so 120 000 samples in total were saved. Densities were estimated and plotted, and summary statistics were computed from the estimated densities. The posterior means (± standard error) of heritability and repeatability were 0.22 ± 0.06 and 0.32 ± 0.05, respectively. These point estimates of genetic parameters were within the range of literature values, although on the high side. The posterior mean (± standard error) of genetic response to selection, defined as the difference between the mean breeding values of the selected lines and that of the base population, was 1.37 ± 0.43 pigs after five cycles of selection. The regression (through the origin) of breeding values in the selected lines on generation was 0.25 ± 0.08 pigs. Several informative priors constructed from information obtained with field data in this population were used to examine their influence on inferences. The priors were influential because of the relatively small scale of the experiment. An analysis excluding data from one of the control lines gave smaller genetic variance and heritability, and a smaller response to selection. However, it appears that selection for litter size is effective, but that the true rate of response is probably smaller than data from this experiment suggest.

Probing of active site structure of lipoprotein lipase: contribution of activation entropy in the catalysis

In this study, I have utilized the chromogenic short-chain esters of p-nitrophenol as substrates for probing the active site structure of lipoprotein lipase (LPL). The results indicated that there is a consistent trend in the decrease of the Michaelis-Menten constant with increase of the acyl-chain length. Therefore, it was concluded that the decrease of reactivity with increased chain length is probably not a consequence of a lower affinity of the substrate for the enzyme. The fact that butyrate ester has the optimum acyl-chain length to be a substrate of LPL can be attributed to its chain length being long enough for optimum interaction with the active site His-Ser-Asp triad in forming the transition state complex; yet it is short enough to provide freedom for optimum positioning of the ester bond for transition state complex formation. It is likely that, because of the structural features of the enzyme active site, the increase of the acyl-chain of the substrate from C4 to C5 initiates the contact between the hydrocarbon tail of the acyl-chain and the hydrophobic surface of the active site pocket. Such an interaction, although it causes the stabilization of the ground state enzyme-substrate complex, also causes a large increase in negative activation entropy because of the restricted random motion of the bound substrate. The latter effect is also the likely cause for the progressively lower reactivity of the enzyme with the increase of acyl-chain length above C4, as seen in the LPL-catalyzed lipolysis of monoacid triacylglycerols.

Obstructive jaundice secondary to ruptured hepatocellular carcinoma into the common bile duct. Surgical experiences of 20 cases

BACKGROUND

Hepatocellular carcinoma (HCC) presenting as obstructive jaundice caused by floating tumor debris in common bile duct is rare. Taiwan has a high incidence of HCC and cirrhosis. The authors report their clinical experiences and evaluate the results of different treatment modalities for this disease.

METHODS

A retrospective study was undertaken to review 20 patients with obstructive jaundice secondary to ruptured HCC into common bile duct during the 12 years period.

RESULTS

All patients on initial examination had recurrent episodic jaundice or cholangitis. Jaundice was relieved by nonsurgical, percutaneous transhepatic biliary stenting in 4 patients and surgical intubation with T-tube drainage in 16. Types of treatment for those who were treated nonsurgically were percutaneous transhepatic biliary stenting in two patients, followed by transcatheter hepatic arterial embolization in another two patients. For the 16 patients who were treated surgically, the types of treatment were T-tube or Y-tube drainage in 11, T-tube drainage followed by hepatic resection in 2, T-tube drainage and hepatic arterial ligation in 1, and T-tube drainage followed by transcatheter hepatic arterial embolization in the other 2. Liver cirrhosis was the associated disease in 12 (75%). Four patients (20%) died in the hospital. The mean survival time for 12 patients with only surgical or nonsurgical biliary stenting was 3.9 months. For the three patients with percutaneous hepatic arterial embolization, the mean survival time was 8.0 months. Two patients who had undergone hepatic resection had a better postoperative survival time, with one surviving for more than 5 years.

CONCLUSION

Clinical features, types of management, operative findings, and survival in 20 patients with HCC obstructing the common bile duct by tumor thrombi were reviewed. Not all patients with this disease were terminally ill. With proper management, good palliation and occasional cure are possible.

Obstructive jaundice secondary to ruptured hepatocellular carcinoma into the common bile duct. Surgical experiences of 20 cases

BACKGROUND

Hepatocellular carcinoma (HCC) presenting as obstructive jaundice caused by floating tumor debris in common bile duct is rare. Taiwan has a high incidence of HCC and cirrhosis. The authors report their clinical experiences and evaluate the results of different treatment modalities for this disease.

METHODS

A retrospective study was undertaken to review 20 patients with obstructive jaundice secondary to ruptured HCC into common bile duct during the 12 years period.

RESULTS

All patients on initial examination had recurrent episodic jaundice or cholangitis. Jaundice was relieved by nonsurgical, percutaneous transhepatic biliary stenting in 4 patients and surgical intubation with T-tube drainage in 16. Types of treatment for those who were treated nonsurgically were percutaneous transhepatic biliary stenting in two patients, followed by transcatheter hepatic arterial embolization in another two patients. For the 16 patients who were treated surgically, the types of treatment were T-tube or Y-tube drainage in 11, T-tube drainage followed by hepatic resection in 2, T-tube drainage and hepatic arterial ligation in 1, and T-tube drainage followed by transcatheter hepatic arterial embolization in the other 2. Liver cirrhosis was the associated disease in 12 (75%). Four patients (20%) died in the hospital. The mean survival time for 12 patients with only surgical or nonsurgical biliary stenting was 3.9 months. For the three patients with percutaneous hepatic arterial embolization, the mean survival time was 8.0 months. Two patients who had undergone hepatic resection had a better postoperative survival time, with one surviving for more than 5 years.

CONCLUSION

Clinical features, types of management, operative findings, and survival in 20 patients with HCC obstructing the common bile duct by tumor thrombi were reviewed. Not all patients with this disease were terminally ill. With proper management, good palliation and occasional cure are possible.

Two classes of proteins and mRNAs in Lilium longiflorum L. indentified by human vitronectin probes

Vitronectin (VN) is a substrate adhesion molecule, an extracellular matrix glycoprotein that facilitates cell adhesion and cell movement in animals. We have reported the cross-reactivity of a 55-kD protein in plants with rabbit anti-human VN antibodies and the presence of VN-like sequences in plant genomes using a human VN cDNA probe. We have extended these studies by using human VN riboprobes to detect VN-like mRNAs in lily (Lilium longiflorum L.) and soybean. In both species, two mRNAs were detected. We have also identified a new cross-reactive protein (41 kD) using a different preparation of human VN antiserum. In lily roots five 41-kD isoforms were observed, whereas only three of these isoforms accumulated in leaves. Monospecific antibodies prepared against the plant proteins cross-reacted with the human VN protein and vice versa. We have purified the 41-kD protein using two-dimensional gel electrophoresis, and amino acid composition analysis indicates that it is similar in composition to human VN.

Carbon dioxide-enhanced ultrasonography of liver tumors

CO2 gas-enhanced ultrasonography was performed in 37 patients (47 studies) for the purpose of detecting small tumors and evaluating differential diagnosis. With conventional ultrasonography, 62 lesions were identified in 25 patients with HCC, 13 tumors were identified in eight patients with hemangioma, and multiple tumors were found in four patients with metastatic adenocarcinoma. CO2-enhanced ultrasonography detected five additional hemangiomas, 12 additional nodules in HCC, and the same number of metastatic nodules. The patterns of CO2 enhancement were characterized as homogeneous, heterogeneous, rim, internal spotted, negative, and mixed (more than one pattern in one lesion). The rim enhancement pattern was found to be specific for hemangioma. The internal spotted enhancement pattern was found exclusively in HCC. All the lesions that demonstrated negative enhancement were treated HCC. All the metastatic tumors demonstrated the mixed rim and internal spotted enhancement pattern. We suggest that CO2-enhanced ultrasonography is a useful tool in detecting small liver tumors. It can also help in the differentiation among various hepatic tumors.

Regulation of bone marrow stromal cell differentiation by cytokines whose receptors share the gp130 protein

The bone marrow stroma consists of a heterogeneous population of cells which participate in osteogenic, adipogenic, and hematopoietic events. The murine stromal cell line, BMS2, exhibits the adipocytic and osteoblastic phenotypes in vitro. BMS2 differentiation was examined in response to cytokines which share the gp130 signal transducing protein within their receptor complex. Four of the cytokines (interleukin 6, interleukin 11, leukemia inhibitory factor, and oncostatin M) inhibited hydrocortisone-induced adipocyte differentiation in a dose dependent manner based on lipid accumulation and lipoprotein lipase enzyme activity. Inhibition occurred only when the cytokines were present during the initial 24 h of the induction period; after 48 h their effects were diminished. Likewise, these cytokines increased alkaline phosphatase enzyme activity twofold in preadipocyte BMS2 cells. Both leukemia inhibitory factor and oncostatin M induced early active gene expression in resting preadipocyte BMS2 cells and decreased the steady state mRNA level of a unique osteoblastic gene marker, osteocalcin. A fifth cytokine whose receptor complex shares the gp130 protein, ciliary neurotrophic factor, did not significantly regulate stromal cell differentiation when added by itself. However, with the addition of a missing component of its receptor complex, ciliary neurotrophic factor receptor alpha protein, this cytokine also inhibited BMS2 adipogenesis. Together, these data indicate that the cytokines whose receptors share the gp130 protein can modulate stromal cell commitment to the adipocyte and osteoblast differentiation pathways.

Effects of highly selective vagotomy and additional procedures on gastric emptying in patients with obstructing duodenal ulcer

A solid gastric emptying study was conducted on 46 patients more than 1 year after highly selective vagotomy (HSV) and additional procedures for obstructing duodenal ulcer and on 21 patients after HSV alone for uncomplicated duodenal ulcer. The additional procedures included dilatation (n = 14; HSV + D group), Holle pyloroplasty (n = 14; HSV + P group), and Jaboulay gastroduodenostomy (n = 18; HSV + GD group). The test meal consisted of two eggs labeled with 99mTc sulfur colloid, two slices of white bread toast, and 300 ml of orange juice (total 322 kcal). Gastric emptying curves and emptying parameters (t1/2, half emptying time; lag phase, TLAG; emptying rate, k; and beta value) were compared with those of 17 healthy volunteers, the normal control group. The patients after HSV alone had an almost normal gastric emptying. The HSV + D group showed a significant delay from minute 45 to the end of the emptying curve, corresponding to a longer t1/2 (p = 0.02), and a slower emptying rate (p = 0.029). The HSV + P group approached a nearly normal emptying curve, corresponding to an insignificant difference in emptying parameters. The HSV + GD group had significantly faster emptying from minute 15 to the end of the emptying curve, corresponding to a faster t1/2 (p = 0.0005), a shorter lag phase (p = 0.027), and a faster emptying rate (p = 0.021). Recurrent ulcerations were noted in one patient (4.8%) of the HSV alone group, five (35.7%) of the HSV + D group, one (7.1%) of the HSV + P group, and one (5.6%) of the HSV + GD group.(ABSTRACT TRUNCATED AT 250 WORDS)

Triglyceride-rich lipoprotein interactions with Lp(a)

We found a significantly reduced incidence of increased lipoprotein(a) (Lp(a)) levels in subjects with triglycerides (TG) greater than 150 mg/dl compared with those with TG levels lower than 150 mg/dl. This was the case in patients with angiographically documented coronary artery disease (CAD) and in subjects with no CAD. We explored the potential role of lipoprotein lipase (LPL) in mediating this relationship. Lp(a) and LDL2 exhibited a minimal effect on the rate constant for degradation of VLDL-TG by LPL (13% inhibition). Binding analyses indicated no differences between VLDL and LDL with respect to Lp(a) binding, and lipolysis only reduced binding by 30% at 75% degradation of VLDL-TG. Our study indicates that the inverse relationship between elevated plasma TG and Lp(a) levels is not caused by activation of LPL by Lp(a) either due to failure of Lp(a) to bind to VLDL or its lipolytic remnants. It is hypothesized that this relationship could stem from the enhanced clearance of TG-rich lipoproteins in individuals with higher levels of Lp(a) by receptor-mediated events.

Effects of albumin and apolipoprotein C-II on the acyl-chain specificity of lipoprotein lipase catalysis

In this study we used monoacid triacylglycerols of various acyl-chain lengths as substrates for probing the active-site structure and substrate specificity of lipoprotein lipase (LPL). An unexpected finding was that the albumin ligand binding site is accessible not only to long-chain fatty acids for its recognized functional role as a fatty acid acceptor, but also to short- and medium-chain monoacid triacylglycerol substrates. The observed striking inhibitory effect (99%) of albumin on the LPL-catalyzed hydrolysis of trihexanoylglycerol is probably the result of the high affinity interaction of albumin with this substrate. Spectrophotometric analyses indicated that there is one high affinity binding site per albumin molecule (apparent KD = 1.8 +/- 0.9 microM) for the interaction with trihexanoylglycerol. Despite LPL acyl-chain specificity being obscured by the substrate binding effect of albumin, a systematic study of the lipolysis reaction under various assay conditions demonstrated that tributyroylglycerol represents the best substrate for LPL, and the preferential order of LPL catalysis for both the basal and apoC-II-activated activities is: C4 > C6 > C8 > C10 > C12 > C18:1. In some assay conditions, the presence of albumin affects the above-mentioned order, which can be attributed to substrate binding by albumin, rather than an alteration in the specificity of LPL. The synergistic effect of apoC-II and albumin resulted in the preferential activation of LPL for the hydrolysis of long-chain triacylglycerols. Even with optimal assay conditions for the hydrolysis of long chain triacylglycerols, there is still a preferential reactivity of LPL with short- and medium-chain triacylglycerols.

A reappraisal of cholangiocarcinoma in patient with hepatolithiasis

BACKGROUND

Hepatolithiasis associated with cholangiocarcinoma is not often encountered. During the past 3 years, an increased incidence of patients with hepatolithiasis associated with cholangiocarcinoma was noted. Data were needed to reliably determine the incidence of this disease.

METHODS

Data concerning the relationship between cholangiocarcinoma and hepatolithiasis are presented. The treatment modalities and factors that influence long-term survival are discussed.

RESULTS

The overall incidence of cholangiocarcinoma in association with hepatolithiasis was 5.0% (55 in 1105). Before 1987, 65% of cholangiocarcinoma in association with hepatolithiasis was diagnosed postoperatively. After 1987, the incidence of accurate preoperative diagnosis increased (22.8%), and in most of the other instances (62.8%), the diagnosis was made at laparotomy. Surgical procedures consisted of common bile duct exploration with T-tube drainage (100%) and hepatectomy (38.2%). Mortality for patients who underwent surgery was 5.4%; they died of recurrent cholangitis. The overall median survival time of patients with cholangiocarcinoma in association with hepatolithiasis was 10.4 months; the 1-, 2-, and 4-year cumulative survival rates were 30.0%, 12.7%, and 3.6%, respectively. Patients with hepatectomy or the presence of mucobilia had better survival rates (P < 0.05).

CONCLUSIONS

The overall incidence of hepatolithiasis associated with cholangiocarcinoma was 5%. In most patients with cholangiocarcinoma in association with hepatolithiasis, diagnosis can be made preoperatively and at laparotomy. Patients with hepatectomy or presence of mucobilia had better survival rates.

A reappraisal of cholangiocarcinoma in patient with hepatolithiasis

BACKGROUND

Hepatolithiasis associated with cholangiocarcinoma is not often encountered. During the past 3 years, an increased incidence of patients with hepatolithiasis associated with cholangiocarcinoma was noted. Data were needed to reliably determine the incidence of this disease.

METHODS

Data concerning the relationship between cholangiocarcinoma and hepatolithiasis are presented. The treatment modalities and factors that influence long-term survival are discussed.

RESULTS

The overall incidence of cholangiocarcinoma in association with hepatolithiasis was 5.0% (55 in 1105). Before 1987, 65% of cholangiocarcinoma in association with hepatolithiasis was diagnosed postoperatively. After 1987, the incidence of accurate preoperative diagnosis increased (22.8%), and in most of the other instances (62.8%), the diagnosis was made at laparotomy. Surgical procedures consisted of common bile duct exploration with T-tube drainage (100%) and hepatectomy (38.2%). Mortality for patients who underwent surgery was 5.4%; they died of recurrent cholangitis. The overall median survival time of patients with cholangiocarcinoma in association with hepatolithiasis was 10.4 months; the 1-, 2-, and 4-year cumulative survival rates were 30.0%, 12.7%, and 3.6%, respectively. Patients with hepatectomy or the presence of mucobilia had better survival rates (P < 0.05).

CONCLUSIONS

The overall incidence of hepatolithiasis associated with cholangiocarcinoma was 5%. In most patients with cholangiocarcinoma in association with hepatolithiasis, diagnosis can be made preoperatively and at laparotomy. Patients with hepatectomy or presence of mucobilia had better survival rates.

A reappraisal of cholangiocarcinoma in patient with hepatolithiasis

BACKGROUND

Hepatolithiasis associated with cholangiocarcinoma is not often encountered. During the past 3 years, an increased incidence of patients with hepatolithiasis associated with cholangiocarcinoma was noted. Data were needed to reliably determine the incidence of this disease.

METHODS

Data concerning the relationship between cholangiocarcinoma and hepatolithiasis are presented. The treatment modalities and factors that influence long-term survival are discussed.

RESULTS

The overall incidence of cholangiocarcinoma in association with hepatolithiasis was 5.0% (55 in 1105). Before 1987, 65% of cholangiocarcinoma in association with hepatolithiasis was diagnosed postoperatively. After 1987, the incidence of accurate preoperative diagnosis increased (22.8%), and in most of the other instances (62.8%), the diagnosis was made at laparotomy. Surgical procedures consisted of common bile duct exploration with T-tube drainage (100%) and hepatectomy (38.2%). Mortality for patients who underwent surgery was 5.4%; they died of recurrent cholangitis. The overall median survival time of patients with cholangiocarcinoma in association with hepatolithiasis was 10.4 months; the 1-, 2-, and 4-year cumulative survival rates were 30.0%, 12.7%, and 3.6%, respectively. Patients with hepatectomy or the presence of mucobilia had better survival rates (P < 0.05).

CONCLUSIONS

The overall incidence of hepatolithiasis associated with cholangiocarcinoma was 5%. In most patients with cholangiocarcinoma in association with hepatolithiasis, diagnosis can be made preoperatively and at laparotomy. Patients with hepatectomy or presence of mucobilia had better survival rates.

Liver transplantation for a hepatitis B-related cirrhotic patient

A patient with chronic end-stage liver cirrhosis resulting from a hepatitis B viral infection had a successful liver transplantation performed on 1 July 1991. Preoperative serology revealed that both HBsAg and HBeAg were positive, and the anti-HBs antibody was negative. Immunoprophylaxis included active immunization, as well as injections of large doses of hepatitis B immunoglobulin (HBIG) given perioperatively to reverse the antigen status. The patient has been anti-HBs antibody positive for more than 10 months since the transplantation. The immunoprophylaxis protocol used has been effective in the prevention of hepatitis B viral reinfection.

[Successful embolectomy for acute mesenteric artery occlusion]

Although acute mesenteric ischemia causing bowel necrosis, a surgical emergency, has been diagnosed with increasing frequency today, it remains as lethal as it ever was, with a mortality rate of 70% to 80%. The high mortality rate can be attributed to delayed diagnosis and the presence of underlying disease. Earlier and more liberal use of angiography in patients with high suspicion of acute mesenteric ischemia is mandatory. We report here to a patient, presenting with acute abdomen and bloody stools, who was highly suspected to have superior mesenteric arterial occlusion. He received emergent angiography and successful embolectomy without bowel resection and second-look operation. The post-operative course was rather smooth. An aggressive surgical approach must be considered, and the second-look procedure should be used when the bowel viability is questionable at the first operation. Postoperative anticoagulation therapy should be given when indicated.

Eosinophilic gastroenteritis: 10 years experience

Eight patients (five men, three women), mean age 36.9 +/- 13.5 (17-60) yr, were diagnosed to have eosinophilic gastroenteritis. The condition was proved in five patients by biopsies through endoscope, and in three, by operation. All had hypereosinophilia (absolute eosinophil count of 1,337-21,787/cm3). According to Klein classification, two had mucosal disease, three had muscle layer disease, and three, subserosal disease. The most common symptoms were abdominal pain (100%), diarrhea (62.5%), vomiting (62.5%), and nausea (50%). Four patients (50%) had symptoms for more than 1 yr before diagnosis. Barium studies revealed mucosal edema and/or thickening of the small intestinal wall in three cases (including one case with ulceration), partial gastric outlet obstruction in one case, and narrowing of lumen of the terminal ileum in one case. Hypotonic duodenogram revealed double contour in one case. Ultrasound examination revealed thickening of the intestinal wall in two cases; computer tomography revealed thickening of the intestinal wall in one case. All patients were treated with steroid (40 mg/day for initial dose and relapse; 5-10 mg/day for maintenance). The symptoms subsided and the eosinophil counts returned to normal within 2 wk in seven patients and 1 month in one. Of six patients being followed up for 2-10 yr, one had remission, four needed small maintenance dose of steroid, and one suffered from relapse with intestinal perforation.

The dilemma of negative analysis of variance estimators of intraclass correlation

At least two common practices exist when a negative variance component estimate is obtained, either setting it to zero or not reporting the estimate. The consequences of these practices are investigated in the context of the intraclass correlation estimation in terms of bias, variance and mean squared error (MSE). For the one-way analysis of variance random effects model and its extension to the common correlation model, we compare five estimators: analysis of variance (ANOVA), concentrated ANOVA, truncated ANOVA and two maximum likelihood-like (ML) estimators. For the balanced case, the exact bias and MSE are calculated via numerical integration of the exact sample distributions, while a Monte Carlo simulation study is conducted for the unbalanced case. The results indicate that the ANOVA estimator performs well except for designs with family size n = 2. The two ML estimators are generally poor, and the concentrated and truncated ANOVA estimators have some advantages over the ANOVA in terms of MSE. However, the large biases may make the concentrated and truncated ANOVA estimators objectionable when intraclass correlation (ϱ) is small. Bias should be a concern when a pooled estimate is obtained from the literature since ϱ<0.05 in many genetic studies.