Prognostic value of left atrial stiffness estimated using echocardiography in dogs with myxomatous mitral valve disease

INTRODUCTION

No studies have investigated the prognostic value of left atrial stiffness (LASt) estimated using echocardiography in dogs with myxomatous mitral valve disease (MMVD).

ANIMALS

Seventy-two dogs had MMVD and 46 dogs were healthy dogs.

MATERIALS AND METHODS

Clinical retrospective cohort study. The survival information of MMVD dogs that underwent echocardiographic examination was obtained. The peak velocities of early diastolic transmitral flow (E) and mitral annular motion as determined by pulsed wave Doppler (E') were determined. The left atrial reservoir strain (ε_S) was determined by two-dimensional speckle tracking echocardiography of the left atrium. The LASt was estimated by the formula: E/E'/ε_S. The 95% prediction interval of LASt was computed from the data of the healthy dogs.

RESULTS

Seventeen dogs having MMVD died of cardiac-related causes with 55 MMVD dogs censored. The MMVD dogs with LASt > its 95% upper prediction limit (LASt > 0.56; n = 26; median survival time, 484 days; 95% confidence interval, 283 days-indeterminable) had shorter survival times (P<0.001) than those with LASt ≤ its 95% upper prediction limit (LASt ≤ 0.56; n = 46; median survival time, >1112 days; 95% confidence interval, indeterminable). Multivariable Cox's proportional hazard analysis demonstrated that the ratio of the left atrial dimension to the aortic annulus dimension and LASt were independent predictors of cardiac-related death among conventional echocardiographic indices, ε_S and LASt in MMVD dogs.

CONCLUSIONS

In dogs with MMVD, increased LASt estimated using echocardiography is an independent predictor of cardiac-related death, and LASt can be more useful for prognostication than ε_S.

Incremental predictive value of echocardiographic indices of right ventricular function in the assessment of long-term prognosis in dogs with myxomatous mitral valve disease

INTRODUCTION

Few studies have evaluated the utility of echocardiographic indices of right ventricular (RV) function in predicting prognosis in dogs with myxomatous mitral valve disease (MMVD).

ANIMALS

Sixty-seven client-owned dogs were diagnosed with MMVD.

MATERIALS AND METHODS

clinical cohort study. Dogs diagnosed with American college of veterinary internal medicine (ACVIM) stage B2, C or D between April 2014 and March 2017 were enrolled. Long-term outcomes were assessed by telephone or from the medical record. The primary end-point was defined as cardiac-related death. Echocardiographic indices of RV function, including the RV Tei index, free wall and septal RV longitudinal strain, were obtained. Univariable and multivariable Cox proportional hazard analyses were used to identify variables predictive of cardiac-related death.

RESULTS

Twenty-four dogs died during the follow-up period. The median follow-up time was 482 days, and the median survival time for dogs with cardiac-related death was 230 days. For cardiac-related death, peak early diastolic mitral inflow velocity, ACVIM stage C or D, tricuspid regurgitation velocity, RV Tei index and RV end-diastolic area were predictors in univariable Cox proportional hazard analysis. In multivariable Cox proportional analysis adjusted for the left atrial to aorta ratio, peak early diastolic mitral inflow velocity and ACVIM stage, an increase in the Tei index by 0.1 increased the hazard ratio of cardiac-related death by 33% (95% confidence interval, 16-70%; P = 0.002).

CONCLUSIONS

In dogs with MMVD, RV dysfunction assessed by the Tei index is an independent predictor of cardiac-related death.

The Repeatability and Left Atrial Strain Analysis Obtained via Speckle Tracking Echocardiography in healthy Dogs

INTRODUCTION

In left atrial (LA) strain-derived two-dimensional speckle tracking echocardiography, the reference intervals in healthy dogs can provide useful information to evaluate the LA function in dogs with heart disease.

ANIMALS

Six laboratory beagles and 120 privately owned dogs without cardiac diseases were recruited.

MATERIALS AND METHODS

The LA strain and strain rate (SR) and echocardiographic indices were obtained in dogs who underwent standard echocardiography and offline analysis for LA strain and SR measurement by speckle tracking echocardiography.

RESULTS

The intra-observer within-day variations of strain variables showed adequate repeatability (coefficient of variation <20%). The mean values of strain were 25.37 for the LA reservoir function, 11.06 for the LA conduit function, and 14.17 for the LA booster-pump function; the strain was significantly correlated with the LA fractional volume change at each phasic function. The left atrial longitudinal strain during early ventricular diastole showed moderate correlation with the peak velocity of early diastolic transmitral flow (r = 0.5560) and ratio of peak velocity of early diastolic transmitral flow to peak velocity of late transmitral flow (r = 0.5515). In multiple regression analysis, only age was significantly related to the strain/SR and volumetric change indices, indicating conduit function.

CONCLUSIONS

Left atrial speckle tracking echocardiographic analysis provided useful information to assess the LA function in healthy dogs. The influencing factors on strain and SR variables including the age, body weight, and heart rate should be considered in interpretation of these parameters in a clinical setting.

Transcranial Doppler Ultrasound Examination in Dogs with Suspected Intracranial Hypertension Caused by Neurologic Diseases

Background

Transcranial Doppler ultrasound examination (TCD) is a rapid, noninvasive technique used to evaluate cerebral blood flow and is useful for the detection of intracranial hypertension in humans. However, the clinical usefulness of TCD in diagnosing intracranial hypertension has not been demonstrated for intracranial diseases in dogs.

Objectives

To determine the association between the TCD variables and intracranial hypertension in dogs with intracranial diseases.

Animals

Fifty client‐owned dogs with neurologic signs.

Methods

Cross‐sectional study. All dogs underwent TCD of the basilar artery under isoflurane anesthesia after magnetic resonance imaging (MRI). Dogs were classified into 3 groups based on MRI findings: no structural diseases (group I), structural disease without MRI evidence of intracranial hypertension (group II), and structural disease with MRI evidence of intracranial hypertension (group III). The TCD vascular resistance variables (resistive index [RI], pulsatility index [PI], and the ratio of systolic to diastolic mean velocity [Sm/Dm]) were measured.

Results

Fifteen, 22, and 13 dogs were classified into groups I, II, and III, respectively. Dogs in group III had significantly higher Sm/Dm (median, 1.78; range, 1.44–2.58) than those in group I (median, 1.63; range, 1.43–1.75) and group II (median, 1.62; range, 1.27–2.10). No significant differences in RI and PI were identified among groups.

Conclusions and Clinical Importance

Our findings suggest that increased Sm/Dm is associated with MRI findings of suspected intracranial hypertension in dogs with intracranial diseases and that TCD could be a useful tool to help to diagnose intracranial hypertension.

Washout Ratio in the Hepatic Vein Measured by Contrast-Enhanced Ultrasonography to Distinguish Between Inflammatory and Noninflammatory Hepatic Disorders in Dogs

Background

Perflubutane microbubbles, a second‐generation ultrasound contrast agent, are phagocytized by Kupffer cells. This characteristic may be useful to differentiate diffuse hepatic diseases in dogs.

Hypothesis/objectives

To determine whether the washout ratio in the hepatic vein (HV) measured by contrast‐enhanced ultrasonography (CEUS) can distinguish between inflammatory and noninflammatory hepatic disorders in dogs.

Animals

Forty‐one client‐owned dogs with hepatic disorders including 14 with hepatitis, 7 with primary hypoplasia of the portal vein (PHPV), 9 with congenital portosystemic shunt (cPSS), and 11 with other hepatopathy were enrolled. Six dogs without hepatic disease also were evaluated as healthy controls.

Methods

Dogs with hepatic disorders were prospectively included. Contrast‐enhanced ultrasonography of the HV was performed for 2 minutes. Washout ratio was defined as the attenuation rate from peak intensity to the intensity at the end of the CEUS study.

Results

Washout ratio in the hepatitis group (median, 18.0%; range, 2.0–37.0%) was significantly lower than that of the PHPV (median, 52.2%; range, 11.5–86.3%), cPSS (median, 60.0%; range, 28.6–77.4%), other hepatopathy (median, 70.5%; range, 26.6–88.4%), and normal (median, 78.0%; range, 60.7–91.7%) groups. The area under the receiver operating characteristic curve for hepatitis was 0.960, with a 95% confidence interval (CI) of 0.853–0.990. Washout ratio ≤37.1% resulted in a sensitivity of 100% (95% CI, 78.5–100%) and specificity of 85.2% (95% CI, 67.5–94.1%) for the prediction of hepatitis.

Conclusions and Clinical Importance

Washout ratio can distinguish hepatitis from the other noninflammatory disorders with high accuracy. This result might reflect impaired Kupffer cell phagocytosis in dogs with hepatitis.

Left Atrial Strain at Different Stages of Myxomatous Mitral Valve Disease in Dogs

Background

Decreased function of the left atrium (LA) is a useful prognostic indicator in dogs with myxomatous mitral valve disease (MMVD). In humans, LA strain is a novel severity indicator of mitral regurgitation, but its clinical utility in dogs has not been confirmed.

Objectives

To examine whether LA strain as evaluated with speckle‐tracking echocardiography is associated with MMVD stage in dogs.

Animals

Fifty‐two client‐owned dogs with MMVD.

Methods

Cross‐sectional study. Dogs were classified as stage B1, B2, C, or D, according to the American College of Veterinary Internal Medicine consensus. Physical examination findings and echocardiographic variables were compared among the groups. To assess the comparative accuracy of echocardiographic variables in identifying dogs with the presence or history congestive heart failure (CHF), receiver operating characteristic curves and multivariate logistic analysis were used.

Results

There were no significant differences in parameters of LA strain between B1 and B2 groups. However, LA longitudinal strain during atrial contraction (ε_A) (median, 19.1%; interquartile range, 15.3–24.3% in B1, 19.6%; 14.1–21.4% in B2, 6.2%; 3.18–11.2% in C/D) and during ventricular systole (ε_S) (32.7%; 28.9–39.2% in B1, 35.6%; 31.7–41.9% in B2, 23.6%; 16.9–26.1% in C/D) were significantly lower in stages C/D than in stages B1 and B2. In multivariate logistic regression analysis, ε_A and peak early diastolic mitral inflow velocity were identified as independent indicators of stage C/D.

Conclusions and Clinical Importance

ε_A was the best predictor of the presence or history of CHF. Further studies are needed to determine the clinical implications of these findings for treatment decisions and prognosis determination.

Localization of Toll-like Receptor (TLR) 2 and TLR4 mRNA in the Colorectal Mucosa of Miniature Dachshunds with Inflammatory Colorectal Polyps

Inflammatory colorectal polyps (ICRPs) are characterized by the formation of multiple or solitary polyps with marked neutrophil infiltration in the colorectal area, and are speculated to be a novel form of breed-specific canine idiopathic inflammatory bowel disease (IBD). In human IBD, toll-like receptor (TLR) 2 and TLR4 have been reported to be involved in the pathogenesis of the disease. The aim of this study was to evaluate the expression of TLR2 and TLR4 mRNA in the colorectal mucosa of dogs with ICRPs by in-situ hybridization using an RNAscope assay. Samples of inflamed colorectal mucosa (n = 5) and non-inflamed mucosa (n = 5) from miniature dachshunds (MDs) with ICRPs and colonic mucosa from healthy beagles (n = 5) were examined. TLR2 and TLR4 hybridization signals were localized to the colorectal epithelium, inflammatory cells and fibroblasts in the inflamed colorectal mucosa of affected dogs. The signals were significantly greater in inflamed colorectal epithelium compared with non-inflamed epithelium of MDs with ICRPs and healthy beagles (P <0.05). These results suggest that increased expression of TLR2 and TLR4 mRNA in the inflamed colorectal mucosa results from not only inflammatory cell infiltration, but also the upregulation of TLR2 and TLR4 mRNA in the colonic epithelium.

Prognostic Value of Right Ventricular Tei Index in Dogs with Myxomatous Mitral Valvular Heart Disease

BACKGROUND

The right ventricular (RV) Tei index (TX) has a significant correlation with the severity of pulmonary hypertension. However, the role of RV dysfunction in dogs with myxomatous mitral valvular heart disease (MMVD) has not been addressed.

OBJECTIVES

To investigate the correlation between right ventricular Tei-index (RVTX) and the prognosis for dogs with MMVD.

ANIMALS

Thirty client-owned dogs with MMVD.

METHODS

Clinical cohort study. Dogs were divided into two groups on the basis of the onset of cardiac-related death within 1 year of the first echocardiographic examination. Physical examination and echocardiographic variables were compared between the groups. Receiver operating characteristic (ROC) curves and multivariate logistic analysis were used to assess the comparative accuracy when identifying dogs with cardiac-related death.

RESULTS

The highest accuracy was obtained for RVTX with an area under the ROC curve (AUC) of 0.95 (95% confidence interval [CI] 0.81-0.99) followed by the left atrial to aortic root ratio with an AUC of 0.91 (95% CI 0.74-0.98), peak early diastolic mitral inflow velocity with an AUC of 0.84 (95% CI 0.64-0.94), and Doppler estimates of systolic pulmonary artery pressure with an AUC of 0.84 (95% CI 0.61-0.95). According to the multivariate logistic regression analysis, RVTX was the only independent correlate of cardiac-related death within 1 year.

CONCLUSIONS AND CLINICAL IMPORTANCE

Right ventricular Tei-index has a strong correlation with the prognosis for dogs with MMVD. The most significant independent predictor of death was RVTX in this study.

Vitamin D Status in Different Stages of Disease Severity in Dogs with Chronic Valvular Heart Disease

Background

In humans with heart disease, vitamin D deficiency is associated with disease progression and a poor prognosis. A recent study showed that serum 25‐hydroxyvitamin D [25(OH)D] concentration, the hallmark of vitamin D status, was lower in dogs with heart failure than in normal dogs, and a low concentration was associated with poor outcome in dogs with heart failure.

Objectives

To elucidate the vitamin D status of dogs with chronic valvular heart disease (CVHD) at different stages of disease severity.

Animals

Forty‐three client‐owned dogs with CVHD.

Methods

In this cross‐sectional study, dogs were divided into 3 groups (14 dogs in Stage B1, 17 dogs in Stage B2, and 12 dogs in Stage C/D) according to ACVIM guidelines. Dogs underwent clinical examination including echocardiography. Serum 25(OH)D concentrations were measured in each dog.

Results

Serum 25(OH)D concentration was significantly lower in Stage B2 (median, 33.2 nmol/L; range, 4.9–171.7 nmol/L) and C/D (13.1 nmol/L; 4.9–58.1 nmol/L) than in Stage B1 (52.5 nmol/L; 33.5–178.0 nmol/L) and was not significantly different between Stage B2 and Stage C/D. Among clinical variables, there were significant negative correlations between 25(OH)D concentration and both left atrial‐to‐aortic root ratio and left ventricular end‐diastolic diameter normalized for body weight.

Conclusions and Clinical Importance

These results indicate that vitamin D status is associated with the degree of cardiac remodeling, and the serum 25(OH)D concentration begins to decrease before the onset of heart failure in dogs with CVHD.

Quantitative contrast-enhanced ultrasonographic assessment of naturally occurring pancreatitis in dogs

BACKGROUND

Quantitative contrast-enhanced ultrasonography (CEUS) can detect pancreatic perfusion changes in experimentally induced canine pancreatitis. However, its usefulness in detecting perfusion changes in naturally occurring pancreatitis is unclear.

HYPOTHESIS/OBJECTIVES

To determine the feasibility of using CEUS to detect pancreatic and duodenal perfusion changes in naturally occurring canine pancreatitis.

ANIMALS

Twenty-three client-owned dogs with pancreatitis, 12 healthy control dogs.

METHODS

Dogs diagnosed with pancreatitis were prospectively included. CEUS of the pancreas and duodenum were performed. Time-intensity curves were created from regions of interest in the pancreas and duodenum. Five perfusion parameters were obtained for statistical analyses: time to initial up-slope, peak time (Tp), time to wash-out (TTW), peak intensity (PI), and area under the curve (AUC).

RESULTS

For the pancreas, Tp of the pancreatitis group was prolonged when compared to controls (62 ± 11 seconds versus 39 ± 13 seconds; P < .001). TTW also was prolonged but not significantly (268 ± 69 seconds versus 228 ± 47 seconds; P = .47). PI and AUC were increased when compared to controls (95 ± 15 versus 78 ± 13 MPV; P = .009 and 14,900 ± 3,400 versus 11,000 ± 2,800 MPV*s; P = .013, respectively). For the duodenum, PI and AUC were significantly increased in the pancreatitis group when compared to controls.

CONCLUSIONS AND CLINICAL IMPORTANCE

Contrast-enhanced ultrasonography can detect pancreatic perfusion changes in naturally occurring canine pancreatitis characterized by delayed peak with prolonged hyperechoic enhancement of the pancreas on CEUS. Additionally, duodenal perfusion changes secondary to pancreatitis were observed.

Prognostic value of left atrial function in dogs with chronic mitral valvular heart disease

Background

A strong correlation between left atrial (LA) dysfunction and the severity of cardiac disease has been described in human patients with various cardiac diseases. The role of LA dysfunction in dogs with chronic mitral valvular heart disease (CMVHD) has not been addressed.

Objectives

To investigate the correlation between LA function and the prognosis of dogs with CMVHD.

Animals

Thirty‐eight client‐owned dogs with CMVHD.

Methods

Prospective clinical cohort study. Dogs were divided into 2 groups (survivors and nonsurvivors) based on the onset of cardiac‐related death within 1 year. Physical examination and echocardiographic variables were compared between the groups. For the assessment of the comparative accuracy in identifying patients with cardiac‐related death, receiver operating characteristic (ROC) curves and multivariate logistic analysis were used.

Results

The highest accuracy was obtained for the LA active fractional area change (LA‐FAC_act), with an area under the ROC curve (AUC) of 0.95, followed by the left atrial to aortic root ratio (LA/Ao), with an AUC of 0.94; peak early diastolic mitral inflow velocity (E), with an AUC of 0.85; and LA total fractional area change (LA‐FAC_total), with an AUC of 0.85. In the multivariate logistic regression analysis, LA‐FAC_act emerged as the only independent correlate of cardiac‐related death within 1 year (odds ratio = 1.401, P = .002).

Conclusions and Clinical Importance

Regarding both the size and function, the LA has a strong correlation with the prognosis of dogs with CMVHD. The most significant independent predictor of mortality in this study was LA‐FAC_act.

Early skin toxicity predicts better outcomes, and early tumor shrinkage predicts better response after cetuximab treatment in advanced colorectal cancer

Cetuximab-containing treatments for metastatic colorectal cancer have been shown to have higher overall response rates and longer progression-free and overall survival than other systemic therapies. Cetuximab-related manifestations, including severe skin toxicity and early tumor shrinkage, have been shown to be predictors of response to cetuximab. We hypothesized that early skin toxicity is a predictor of response and better outcomes in patients with advanced colorectal carcinoma. We retrospectively evaluated 62 patients with colorectal adenocarcinoma who had unresectable tumors and were treated with cetuximab in our institution. Skin toxicity grade was evaluated on each treatment day. Tumor size was evaluated using computed tomography prior to treatment and 4-8 weeks after the start of treatment with cetuximab.Patients with early tumor shrinkage after starting treatment with cetuximab had a significantly higher overall response rate (P = 0.0001). Patients with early skin toxicity showed significantly longer overall survival (P = 0.0305), and patients with higher skin toxicity grades had longer progression-free survival (P = 0.0168).We have shown that early tumor shrinkage, early onset of skin toxicity, and high skin toxicity grade are predictors of treatment efficacy and/or outcome in patients with advanced colorectal carcinoma treated with cetuximab.

Qualitative and quantitative contrast-enhanced ultrasonographic assessment of cerulein-induced acute pancreatitis in dogs

Background

Acute pancreatitis (AP) is the most common disease of the canine exocrine pancreas, and accurate noninvasive diagnosis is challenging.

Hypothesis/Objectives

To determine the feasibility of using quantitative contrast‐enhanced ultrasonography (CEUS) to detect pancreatic perfusional changes in cerulein‐induced AP in dogs.

Animals

Six adult female Beagles.

Methods

Each dog received 2 hours of IV infusion with 7.5 μg/kg/h of cerulein diluted in saline. As control, all dogs received 2 hours of IV infusion of saline 2 weeks before cerulein infusion. CEUS of the pancreas and duodenum were performed before (0 hour), and at 2, 4, 6, and 12 hours after saline and cerulein infusion. Time‐intensity curves were created from regions of interest in the pancreas and duodenum. Five perfusional parameters were measured for statistical analysis: time to initial up‐slope, peak time, time to wash‐out, peak intensity (PI), and area under the curve (AUC).

Results

In cerulein‐induced AP, pancreatic PI increased at 2 and 4 hours when compared to 0 hour, and at 2, 4, and 6 hours when compared to control. AUC increased at 4 hours when compared to 0 hour, and at 2 and 4 hours when compared to control. Time to wash‐out was prolonged at 4 hours when compared to control. For saline control, peak time was faster at 2 hours when compared to 0 hour.

Conclusions and Clinical Importance

CEUS parameters PI and AUC can provide useful information in differentiating acute pancreatitis from normal pancreas. Cerulein‐induced AP was characterized by prolonged hyperechoic enhancement on CEUS.

Proton magnetic resonance imaging of diffusion of high- and low-molecular-weight contrast agents in opaque porous media saturated with water

Besides their use in contrast-enhanced proton magnetic resonance imaging (MRI), contrast agents were found to be useful as tracer molecules. Since paramagnetic ions in water have the ability to reduce the T1 of protons around them, MRI can determine the locations of Mn2+ and Gd3+ of ppm concentration in water. In opaque porous media saturated with water, MRI revealed diffusional motions of three contrast agents: MnCl2 (molecular-weight [M.W.], 126), gadolinium-diethylene-triaminepenta acetic acid (Gd-DTPA) (M.W., 743) and albumin (Gd-DTPA) (M.W., 94,000) at a diffusional displacement ratio of 9:5:2. With the aid of these contrast agents, the transport of low- to high-molecular-weight molecules in opaque water media such as living bodies can be observed using MRI.

Proton magnetic resonance imaging of flow motion of heavy water injected into a hollow fiber dialyzer filled with saline

Observations using MRI were performed for the motion of heavy water injected into a hollow fiber dialyzer. A cylindrical dialyzer houses a bundle of 10,000 hollow fibers. Because blood components permeate through the hollow fiber membrane from the interior to the exterior of the hollow fiber, which is the dialysate flow path, uniformity of dialysate flow is required. The dialyzer was initially filled with saline and heavy water was injected into the inlet port of the dialysate flow path. MRI tuned for protons could distinguish the injected heavy water from the already present saline. Due to the specific gravity difference, MRI could observe the sedimentation of the injected heavy water flowing beneath the already present saline. The uniformity of the dialysate flow was supported by the finding that the injected heavy water brought about uniform sedimentation and distributed the already present saline uniformly throughout the entire volume of the dialyzer.

Detection of small degree of nonuniformity in dialysate flow in hollow-fiber dialyzer using proton magnetic resonance imaging

A small degree of nonuniformity in dialysate flow in a hollow-fiber dialyzer was detected using proton magnetic resonance imaging (MRI). Since paramagnetic ions reduce the spin-lattice relaxation time of protons around them, MRI can detect Gd in water. An aqueous solution of a chelate compound of Gd was impulsively injected into the dialysate flow path at a flow rate of 500 cm(3) /m, which is that utilized in actual dialysis. Despite the apparent elimination of Gd from the dialysate flow path by the newly injected dialysate fluid after the injection of Gd was terminated, MRI revealed that Gd remained in the interior of the hollow fiber. The observed structure pattern of the Gd concentration profile revealed that the dialysate flow had a small degree of nonuniformity despite the currently established design to restrict channeling in dialysate flow. Local nonuniformity of the hollow-fiber density and vortex generation in the dialysate flow were considered to cause the nonuniformity in the dialysate flow.

Magnetic resonance imaging of molecular transport in living morning glory stems

MRI was applied to investigate the transport pathways in Morning Glory plant stems. The study was carried out on living plants without affecting their integrity. The architecture of a dicotyledonous plant was deeply characterized: the root system structure and the vascular bundle location were identified, the presence of central voids caused by cell maturation and loss were observed in the stem. Molecular transport components were recognized, by observing the concentration profile of a tracer, which changed with time after its absorption by the plant roots. MRI analysis revealed the presence of an axial transport as the progress of the tracer front through the vascular bundles and a radial molecular transport from the vascular bundles toward the surface of the stem. As a result, the tracer molecular transport formed the parabolic tracer front (PTF). A model was built up through the analysis of the PTF that consisted of an axial front at the peak position and a radial front at the width of the parabolic tail. PTF analysis revealed differences between the tracer transport velocities in the axial and the radial directions in the plant stem. The model revealed that the width of the parabolic tail reflected the magnitudes of diffusion and permeation of the tracer in the plant stem.

Long-term ursodeoxycholic acid therapy is associated with reduced risk of biliary pain and acute cholecystitis in patients with gallbladder stones: a cohort analysis

Whether ursodeoxycholic acid (UDCA) therapy alters the long-term clinical course of gallstones (GS) without stone dissolution remains unknown. We aimed to clarify the relationship between long-term UDCA therapy and risks of biliary pain or acute cholecystitis in GS patients. We also aimed to identify factors affecting the natural course, and to explore a simple patient selection criteria for UDCA therapy. A cohort of 527 uncomplicated GS patients with or without UDCA (600 mg/d) followed for up to 18 years was analyzed. Patients who had frequent attacks or were complicated with cholecystitis were converted to cholecystectomy. History and UDCA therapy were identified on Cox analysis as 2 factors affecting the long-term clinical course. In patients without therapy, history was the only predictor of biliary pain among various patient or stone characteristics; biliary pain was rare in asymptomatic patients, while frequent in symptomatic patients (P <.001). UDCA therapy was associated with reduced risk for biliary pain in both symptomatic (62% vs. 92% in untreated patients at 10 years; P <.001; relative risk, 0.19; 95% CI, 0.10-0.34) and asymptomatic patients (6% vs. 12% in untreated patients at 10 years; P =.037; relative risk, 0.19; 95% CI, 0.04-0.91). Risk for the conversion was also reduced in UDCA-treated symptomatic patients (26% vs. 88% in untreated patients at 10 years, P <.001; relative risk, 0.08; 95% CI, 0.03-0.22). These effects were independent of stone dissolution. Three factors were identified on Cox analysis as affecting GS dissolution: radiolucency, small size (<10 mm) of stones, and visualized gallbladder (GB) on cholecystogram. A selection criteria based on these appears to exhibit high sensitivity (74%) and specificity (95%) for dissolution. UDCA therapy might be considered in symptomatic patients fulfilling these criteria, and also in patients who have significant surgical risk, because the longterm therapy is clearly associated with reduced risk of biliary pain and acute cholecystitis.

Effect of 1.5 T steady magnetic field on neuroconduction of a bullfrog sciatic nerve in a partially active state within several hours after extraction

The bullfrog sciatic nerve within six hours after extraction was determined from the change with time in the action potential and the impedance to be a partially active nerve. Steady magnetic fields have been determined to be ineffective in the neuroconduction in the fresh nerve just after extraction. Although ion motions involved in the neuroconduction in the partially active nerve are not normal, it was confirmed that a 1.5 T steady magnetic field is ineffective in the neuroconduction in the partially active nerve. The obtained results suggest that the neuroconduction in damaged nerves is not affected by the 1.5 T steady magnetic field used in MRI.

Plasma levels of mevalonate and 7alpha-hydroxy-4-cholesten-3-one in chronic liver disease

BACKGROUND AND AIMS

Cholesterol levels in blood tend to be preserved despite hepatic impairment, in contrast to albumin levels and other markers of liver function in patients with liver cirrhosis (LC). We reported previously that the levels of plasma mevalonate (MVA) and 7alpha-hydroxy-4-cholesten-3-one (7alpha3one) closely reflect hepatic synthetic rates of cholesterol and bile acids. The aim of this study was to examine the association between hepatic cholesterogenesis and bile acid synthesis in hepatocellular impairment using these indices.

METHODS

The plasma indices were measured in patients with LC (n = 38) or chronic hepatitis (CH; n = 11) and in normal controls (n = 22). The severity of LC was assessed by the Child-Pugh score.

RESULTS

There were no significant differences in plasma MVA levels between CH, LC and control groups. However, plasma 7alpha3one levels were significantly lower in LC than in CH and control groups (P< 0.01). While MVA levels did not correlate with the Child-Pugh score, there was a significant correlation between 7alpha3one level and Child-Pugh score (P< 0.005). The plasma 7alpha3one level in controls correlated positively with MVA levels (P< 0.01); however, there was no significant correlation between these indices in CH and LC.

CONCLUSION

In chronic liver disease, there was a tendency for hepatic cholesterogenesis to be sustained in the face of hepatocellular impairment, while bile acid synthesis declined in parallel with the severity of impairment.

Dialysate pressure isobars in a hollow-fiber dialyzer determined from magnetic resonance imaging and numerical simulation of dialysate flow

A procedure to determine dialysate pressure isobars by comparing the results of magnetic resonance imaging (MRI) and numerical simulation of the dialysate flow was established. The assumption used in the filtration analyses, that the dialysate pressure varies only in the central-axial direction, is supported by the finding that the determined isobars have no steep radial gradient. MRI of the contrast solution permeating the hollow fibers verifies the uniformity of the hollow fiber density in the dialyzer.

Hepatitis B virus DNA is frequently found in liver biopsy samples from hepatitis C virus-infected chronic hepatitis patients

Human hepatitis B virus (HBV) and hepatitis C virus (HCV) are two major etiologic agents of chronic hepatitis, which is closely related to the development of hepatocellular carcinoma (HCC). A possible involvement of HBV co-infection was investigated in ongoing HCV-related liver diseases in HCV-infected patients. A prevalence of anti-HBc in anti-HCV-positive/HBsAg-negative chronic hepatitis patients and a low copy number of HBV DNA were found in most of the liver biopsy samples of anti-HCV-positive/HBsAg-negative patients. The present data suggest that HBV co-infects frequently with HCV and may play an important role in the development of HCC in the anti-HCV-positive/HBsAg-negative patients with chronic hepatitis.

Short-term effects of 3-hydroxy-3-methylglutaryl-CoA reductase inhibitor on cholesterol and bile acid synthesis in humans

Competitive inhibitors of 3-hydroxy-3-methylglutaryl-CoA reductase improve hypercholesterolemia. However, reports about the effects of these agents on bile acid synthesis, the metabolic pathway of cholesterol, are conflicting. We studied the short-term effect on one of these agents, pravastatin, on bile acid synthesis. Six male volunteers were given 40 mg of pravastatin. Plasma mevalonate level (which reflects cholesterol synthesis) and 7 alpha-hydroxy-4-cholesten-3-one level (which reflects bile acid synthesis) were measured every 2 h for 8 h. These plasma levels were compared to those of the same volunteers without pravastatin. Plasma mevalonate level after 2 h was lower than control (3.0 +/- 1.1 ng/mL vs. 6.7 +/- 2.5, mean +/- SD; P < 0.05). This decrease continued for 8 h (2.5 +/- 0.8 vs. 5.2 +/- 1.5; P < 0.05). On the other hand, plasma 7 alpha-hydroxy-4-cholesten-3-one level did not change until after 6 h; then at 8 h it was lower than control (15.7 +/- 11.8 ng/mL vs. 24.7 +/- 16.9; P < 0.05). According to three-way layout analysis of variance, mevalonate level was influenced by both pravastatin treatment (P < 0.01) and time-course (P < 0.01). On the other hand, the 7 alpha-hydroxy-4-cholesten-3-one level was affected by both individual difference (P < 0.01) and time course (P < 0.01), but pravastatin treatment did not influence this compound. This indicates that bile acid synthesis was influenced by pravastatin, although cholesterol synthesis was inhibited. The short-term inhibition of cholesterol synthesis did not affect bile acid synthesis.

Simultaneous determination of plasma mevalonate and 7alpha-hydroxy-4-cholesten-3-one levels in hyperlipoproteinemia: convenient indices for estimating hepatic defects of cholesterol and bile acid syntheses and biliary cholesterol supersaturation

The high prevalence of cholesterol gallstone disease in hypertriglyceridemic patients may be associated with frequent metabolic defects in cholesterol and bile acid syntheses and in the concomitant formation of bile supersaturated with cholesterol. This study had the two aims: 1) to assess whether the defects as well as the degree of biliary cholesterol supersaturation in patients with hyperlipoproteinemia (HLP) can be estimated by the simultaneous determination of plasma mevalonate (MVL) and 7alpha-hydroxy-4-cholesten-3-one (C4); and 2) to assess the possible application of an estimated cholesterol saturation index ([CSI]E) as a means of evaluating the clinical effects of simvastatin on biliary lipid composition. Biliary cholesterol supersaturation was observed in patients with both IIa and IV HLP types. Consistent with the high activity and steady-state messenger RNA level of 3-hydroxy-3 methylglutaryl coenzyme A (HMG-CoA) reductase, plasma MVL was significantly higher in 86 patients with HLP (38 type IIa, 44.1 +/- 2.4 nmol/L and 48 type IV, 56.7 +/- 2.3; P < .01) than in 41 normolipidemic subjects (34.2 +/- 1.5), closely correlating with the molar percentage of cholesterol in bile (r = .61, P = .0001; n = 86). On the other hand, consistent with the high activity and messenger RNA level of cholesterol 7alpha-hydroxylase, plasma C4 was significantly higher in patients with HLP (type IIa, 28.8 +/- 2.3 nmol/L and type IV, 38.3 +/- 2.7; P < .01) than in normolipidemic subjects (17.4 +/- 1.5). Plasma C4 was closely correlated with plasma MVL (r = .40, P = .0001; n = 86), but was inversely correlated with the molar percentage of bile acids in bile (r = .49, P = .0001; n = 86). Assuming that cholesterol supersaturation in patients with HLP may be governed by both an enhanced cholesterol secretion (closely reflected by plasma MVL) and a decreased secretion of bile acids (closely reflected by plasma C4), the multivariate linear regression-analyses revealed that an index defined as estimated CSI ([CSI]E) (%) in patients with HLP was given by the following equation using plasma MVL and C4 (nmol/L): [CSI]E = 1[MVL] + 0.7[C4] + 44.4. Biliary cholesterol supersaturation in patients treated with simvastatin improved in a manner parallel to the time course of decreases in plasma MVL and C4. The [CSI]E before and at the end of treatment were correlated with biliary CSI. These results indicate that defects of hepatic cholesterogenesis, and bile acid synthesis, and the degree of biliary cholesterol supersaturation in patients with HLP can be estimated exactly by the simultaneous determination of plasma MVL and C4; furthermore [CSI]E may be adopted for clinical use as a convenient index of biliary CSI.

[Three patients with Gilbert's syndrome associated with constitutional excretory defect of indocyanine green]

We routinely perform, as a preoperative liver function test, the indocyanin green (ICG) test in patients scheduled for operations under general anesthesia. Doubts have been raised, however, concerning the necessity for this test, since no abnormalities have ever been detected by it. Nonetheless, we noted a high level of ICG retention and a slight increase in indirect bilirubin in 3 patients, and further investigation led to a diagnosis of Gilbert's syndrome accompanied by constitutional impairment of ICG excretion. This syndrome can be associated with perioperative jaundice in patients with malnutrition and those who received halothane, morphine, or some other agents. Although the indirect bilirubin level increased briefly after surgery, no other abnormalities occurred in the 3 patients. Since this syndrome is asymptomatic and is detected incidentally, the preoperative ICG test was considered to be useful.

Monoclonal antibody against lymphocyte function-associated antigen 1 inhibits the formation of primary biliary cirrhosis-like lesions induced by murine graft-versus-host reaction

Interaction between intercellular adhesion molecule 1 (ICAM-1) and lymphocyte function-associated antigen 1 (LFA-1) might be involved in the pathogenesis of liver diseases. We investigated whether monoclonal antibodies (mAbs) against these two adhesion molecules could inhibit the formation of primary biliary cirrhosis (PBC)-like lesions in an animal model using graft-versus-host reaction (GVHR) with major histocompatibility complex class II disparity. PBC-like hepatic lesions such as cellular infiltration of portal area and nonsupprative destructive cholangitis (NSDC) were generated by injecting spleen T cells of C57BL/6 (B6) mice into (B6. C-H-2bm12 X B6) F1 mice. In the liver of these mice, increased number of LFA-1-positive cells and enhanced expression of ICAM-1 on sinusoidal endothelial cells and bile duct epithelial cells were observed immunohistochemically, when compared with F1 mice without GVHR. Hepatic lesions of these mAb-treated mice were almost completely inhibited in these mice compared with GVHR mice. Furthermore, we studied to determine which anti-LFA-1 mAb or anti-ICAM-1 mAb was essential to inhibit the hepatic lesions. Mice solely treated with anti-LFA-1 mAb showed significant inhibition of hepatic lesions, whereas treatment with anti-ICAM-1 mAb could not inhibit the lesions. Despite the inhibition of hepatic lesions, induction of GVHR and production of antimitochondrial antibodies were not impaired in mAb-treated mice. We conclude that LFA-1 mediates cell infiltration into the liver in this murine model of GVHR and suggest a possible therapeutic role of mAbs to this adhesion molecule in selective autoimmune liver diseases.

Monoclonal antibody against lymphocyte function-associated antigen 1 inhibits the formation of primary biliary cirrhosis-like lesions induced by murine graft-versus-host reaction

Interaction between intercellular adhesion molecule 1 (ICAM-1) and lymphocyte function-associated antigen 1 (LFA-1) might be involved in the pathogenesis of liver diseases. We investigated whether monoclonal antibodies (mAbs) against these two adhesion molecules could inhibit the formation of primary biliary cirrhosis (PBC)-like lesions in an animal model using graft-versus-host reaction (GVHR) with major histocompatibility complex class II disparity. PBC-like hepatic lesions such as cellular infiltration of portal area and nonsupprative destructive cholangitis (NSDC) were generated by injecting spleen T cells of C57BL/6 (B6) mice into (B6. C-H-2bm12 X B6) F1 mice. In the liver of these mice, increased number of LFA-1-positive cells and enhanced expression of ICAM-1 on sinusoidal endothelial cells and bile duct epithelial cells were observed immunohistochemically, when compared with F1 mice without GVHR. Hepatic lesions of these mAb-treated mice were almost completely inhibited in these mice compared with GVHR mice. Furthermore, we studied to determine which anti-LFA-1 mAb or anti-ICAM-1 mAb was essential to inhibit the hepatic lesions. Mice solely treated with anti-LFA-1 mAb showed significant inhibition of hepatic lesions, whereas treatment with anti-ICAM-1 mAb could not inhibit the lesions. Despite the inhibition of hepatic lesions, induction of GVHR and production of antimitochondrial antibodies were not impaired in mAb-treated mice. We conclude that LFA-1 mediates cell infiltration into the liver in this murine model of GVHR and suggest a possible therapeutic role of mAbs to this adhesion molecule in selective autoimmune liver diseases.

Severe acute hepatitis A associated with acute pure red cell aplasia

A rare case of severe acute hepatitis A complicated by pure red cell aplasia (PRCA) is reported. A 60-year-old man with jaundice and hepatomegaly was diagnosed as having acute hepatitis A by positive IgM anti-hepatitis A antibody (anti-HAV). Severe anemia rapidly developed 3 weeks after admission, and the patient was diagnosed with PRCA by both bone marrow smears and erythrocyte survival study. The anemia was transient and bone marrow recovered within 1 week. However, concomitant with bone marrow recovery, the hepatitis worsened. He became drowsy and disoriented and severe jaundice, ascites, prolonged prothrombin time, increased transaminase levels, and abnormal electroencephalogram (EEG) were exhibited. Plasma exchange transfusion and glucagon-insulin (GI) therapy improved the consciousness level, but bilirubin, transaminase levels, and IgM anti-HAV titer remained high. Intravenous administration of lipophilized prostaglandin E1 (lipo-PGE1) was added to the GI therapy. Bilirubin and transaminase levels were normalized in the 8th week after the initiation of this combination therapy (17 weeks after admission). The combined use of lipo-PGE1 with plasma exchange and GI therapy appeared to be useful for the prolonged severe hepatitis in this patient.

Multivariate analysis of risk factors for hepatocellular carcinoma in patients with hepatitis C virus-related liver cirrhosis

To elucidate the risk factors for hepatocellular carcinoma (HCC) in hepatitis C virus (HCV)-related liver cirrhosis (LC), we examined 204 cirrhotic patients negative for hepatitis B surface antigen and positive for HCV antibodies. The independent influence of various clinical characteristics in these patients was analyzed by multiple logistic regression, and the risk factors for HCC were identified. Multiple logistic regression analysis identified and ranked the following four risk factors: male sex (P < 0.001), habitual heavy drinking (P < 0.005), hepatitis B virus antibody positivity (anti-HBs and/or anti-HBc, P < 0.05), and age greater than 60 years (P < 0.05). The odds ratio of HCC was 4.20 (95% confidence interval; CI, 1.80-9.78) in male patients, 3.27 (95% CI, 1.46-7.30) in habitual heavy drinkers, 2.01 (95% CI, 1.01-3.99) in patients positive for hepatitis B virus antibodies, and 2.06 (95% CI, 1.00-4.23) in patients older than 60 years. The cumulative occurrence rates of HCC after blood transfusion were significantly higher in habitual heavy drinkers (4.8%, 49.4%, and 74.7% at 10, 20, and 30 years, respectively) than in non-drinkers (0%, 21.0%, and 23.3% at 10, 20, and 30 years, respectively, P < 0.0003). The mean interval for progression to LC after blood transfusion was significantly shorter in the habitual heavy drinkers than in the non-drinkers (22.4 +/- 4.4 years vs 28.4 +/- 3.9 years; P < 0.0003). This multivariate analysis revealed that habitual heavy drinking and hepatitis B virus antibody positivity are significant risk factors for HCC in HCV-related liver cirrhosis.

The role of previous hepatitis B virus infection and heavy smoking in hepatitis C virus-related hepatocellular carcinoma

OBJECTIVE

Worldwide epidemiological studies have demonstrated that hepatitis C virus (HCV) probably is a causative agent of hepatocellular carcinoma (HCC). However, there are no available reports that clearly identify the risk factors for the development of HCC in HCV-related chronic liver disease (CLD). The aim of the present study is to explore the risk factors for hepatocarcinogenesis in HCV-related CLD.

METHODS

We prospectively observed 412 patients with anti-HCV-positive CLD but without co-infection of hepatitis B virus (232 patients with chronic hepatitis and 180 with liver cirrhosis) for between 0.5 and 15.8 yr (median: 4.9 yr). Risk factors for hepatocarcinogenesis were identified with a Cox proportional-hazard model.

RESULTS

Sixty-three patients (15.3%) developed HCC during the observation period; the cumulative occurrence rates at the end of the 5th, 10th, and 15th yr was 3.7%, 12.1%, and 12.1%, respectively, for chronic hepatitis patients and 23.3%, 49.4%, and 90.7%, respectively, for 180 cirrhotic patients. The Cox proportional-hazard model showed that the risk of hepatocarcinogenesis increased almost 5-fold in cirrhotic patients (risk ratio, 5.14; 95% confidence interval, 2.52-10.46, p = 0.0001), 2-fold in patients with positive antibodies against hepatitis B surface antigen and/or antibodies against hepatitis B core antigen (risk ratio, 2.14; 95% confidence interval, 1.13-4.07, p = 0.0201), and 2.5-fold in heavy smokers (risk ratio, 2.46; 95% confidence interval, 1.11-5.49, p = 0.0276).

CONCLUSION

These epidemiological results indicate that previous infection with hepatitis B virus and heavy smoking (in addition to liver cirrhosis, a known risk factor) play important roles as risk factors for carcinogenesis in HCV-related CLD.

Evidence that the elevation of soluble MHC class I antigens in the serum precedes the onset of graft-versus-host disease and is correlated with the severity of the disease in rats

We examined the changes in the levels of soluble major histocompatibility antigen complex (MHC) class I antigens in the serum under a lethal or nonlethal state of graft-versus-host-disease (GVHD) induced by injecting various doses of PVG rat splenic lymphocytes into (DA x PVG)F1 rats. All rats receiving 4 x 10(8) lymphocytes (lethal dose) died on day 20-36 showing typical features of GVHD, while the injection of 4 x 10(7) cells (nonlethal dose) induced no sign of GVHD. When rats were inoculated with a nonlethal dose of lymphocytes prior to the injection of a lethal dose, all rats survived with or without showing transient GVHD. Preceding the onset of GVHD the levels of soluble class I antigens increased significantly to 1094 +/- 487 ng/ml (mean +/- SD, n = 4) from 3 days after the injection of a lethal dose to the time of death, whilst the levels in the nonlethal dose group remained unchanged. Rats with transient GVHD in the preinoculated group showed the increase of soluble class I antigens to the same extent as rats with lethal GVHD, suggesting that GVHD was systemically ongoing. The levels of soluble class I antigens also correlated with the severity of GVHD as judged by daily observation and histological studies. Rats receiving a lethal dose showed destructive alteration of spleen structure and cellular infiltration in the portal area of the liver before the animals started to show signs of GVHD, whereas rats in the nonlethal dose group exhibited no marked change. These data suggest the possibility of serum soluble class I antigens being not only a diagnostic but also a prognostic marker for GVHD.

L-arginine and endogenous nitric oxide protect the gastric mucosa from endothelin-1-induced gastric ulcers in rats

We have reported that endothelin-1 induces gastric ulcer characterized by a potent long-lasting vasoconstriction of the regional microvasculature. Nitric oxide synthesized from L-arginine has been shown to regulated gastric mucosal blood flow, and inhibition of its synthesis has been shown to delay the healing of gastric ulcers. We examined the effect of exogenous L-arginine and the inhibition of nitric oxide synthesis on the development of endothelin-1-induced gastric ulcers. In rats anesthetized with urethane, a continuous intravenous infusion of L- or D-arginine (10 mg.kg-1.min-1) was followed, 15 min later, by a submucosal injection of endothelin-1 (200 pmol/kg) in the anterior wall of the gastric body. In another group, rats were intravenously pretreated with N omega-nitro-L-arginine-methyl ester (1-10 mg/kg), a nitric oxide synthesis inhibitor, and then injected with endothelin-1 (40 pmol/kg). Twenty-four h later, L-arginine, but not D-arginine, had significantly reduced the extent and the severity of the endothelin-1-induced ulcer (mucosal wall damage, 18.11 +/- 4.79% and 88.14 +/- 7.06%, respectively; mean +/- SD, P < 0.001), and the nitric oxide synthesis inhibitor (10 mg/kg) had increased the endothelin-1-induced mucosal damage (ulcer length, 3.8 +/- 1.2 mm and 1.1 +/- 0.2 mm, respectively, P < 0.01). Continuous gastric mucosal blood flow measurements showed that L-arginine antagonized the endothelin-1-induced vasoconstriction. L-arginine protected the gastric mucosa from the ulcerogenic action of endothelin-1 and antagonized its vasoconstrictive action. The inhibition of endogenous nitric oxide potentiated the ulcerogenic effect of endothelin-1 on rat gastric mucosa.

Accumulation of 7 alpha-hydroxycholesterol in liver tissue of patients with cholesterol gallstones

Patients with cholesterol gallstones have a reduced pool of bile acids. This study was undertaken to clarify the mechanism by which bile acid biosynthesis does not increase to supranormal levels to cause a reexpansion of the pool. We investigated the first two steps of the bile acid biosynthesis pathway by assaying the activities of cholesterol 7 alpha-hydroxylase, the rate-limiting enzyme in this pathway, and 3 beta-hydroxy-delta 5-C27-steroid dehydrogenase/isomerase, and by measuring the concentrations of 7 alpha-hydroxycholesterol and 7 alpha-hydroxy-4-cholesten-3-one in liver specimens from ten patients with cholesterol gallstones and ten gallstone-free controls. In the patients with gallstones, cholesterol 7 alpha-hydroxylase activity, 3 beta-hydroxy-delta 5-C27-steroid dehydrogenase/isomerase activity, and hepatic 7 alpha-hydroxy-4-cholesten-3-one concentration did not significantly different from levels in controls, but hepatic 7 alpha-hydroxycholesterol concentration was more than twofold that of controls (12.9 +/- 2.6 vs 5.3 +/- 1.2 nmol/g liver, P < 0.01). The concentration of 7 alpha-hydroxycholesterol positively correlated with the ratio of cholesterol 7 alpha-hydroxylase activity to 3 beta-hydroxy-delta 5-C27-steroid dehydrogenase/isomerase activity (r = 0.93; P < 0.005) in the gallstone-free controls. In contrast, this correlation disappeared in the patients with gallstones. These results suggest a derangement of the normal 7 alpha-hydroxycholesterol metabolism in the patients with gallstones. The reason for the accumulation of 7 alpha-hydroxycholesterol remains unclear; however, it is possible that, in patients with cholesterol gallstone, the accumulated 7 alpha-hydroxycholesterol causes inappropriate suppression of cholesterol 7 alpha-hydroxylase activity by product inhibition.

Clinical significance of the trimethadione tolerance test in chronic hepatitis: a useful indicator of hepatic drug metabolizing capacity

Trimethadione (TMO) was chosen as an indicator of quantitative hepatic microsomal function, and its pharmacokinetics were studied in 52 patients with chronic hepatitis. Findings in these patients were compared with those for 26 healthy subjects and 13 patients with renal failure. Patients with chronic hepatitis, but not those with renal failure, showed significant reduction in clearance (CL) and prolongation of half-life (t1/2), and the extent of abnormalities was found to reflect the severity of histologic changes in liver tissue. The serum dimethadione (DMO)/TMO ratio 4 h after the administration of TMO altered in parallel with the CL and t1/2 of TMO, and abnormalities in this simple ratio were also related to the histologic severity of changes in the liver tissue. A low DMO/TMO ratio (< 0.4) was associated with advanced histologic changes (chronic active hepatitis with bridging or chronic active hepatitis with cirrhosis), whereas a high DMO/TMO ratio (> 0.4) was associated with mild histologic changes (chronic persistent hepatitis or chronic active hepatitis) (sensitivity, 0.81; specificity, 0.86). These results indicate that the DMO/TMO ratio, which can be obtained from a single blood sampling, reflects the histologic severity of changes in tissue liver, and that the TMO tolerance test is a useful indicator of quantitative liver function.

Increase of deoxycholate in supersaturated bile of patients with cholesterol gallstone disease and its correlation with de novo syntheses of cholesterol and bile acids in liver, gallbladder emptying, and small intestinal transit

A total of 100 nonobese and normolipidemic subjects (29 control subjects, 49 patients with cholesterol stones [CSs], and 22 patients with brown pigment stones) were studied to elucidate the pathogenetic contributions of deoxycholate (DC) to supersaturated bile formation with special reference to de novo syntheses of cholesterol and bile acids in the liver. A higher proportion of DC was observed in gallbladder bile from patients with CSs (CSs; 21.7 +/- 1.4%, mean +/- SEM, vs. control subjects; 10.2 +/- 0.9%). Cholesterol saturation in bile was elevated parallel to the increase of DC (r = .48; P = .0002), irrespective of the existence of stones. In a comparison between the 52 subjects with increased DC in bile (> 10% of biliary bile acids) and the 20 subjects without the increase (< 10%), the molar percentage of cholesterol in bile was significantly higher in the former (9.4 +/- 0.5%) than in the latter (6.7 +/- 0.4%) (P < .001). Consistent with the decrease in steady-state level of low-density lipoprotein (LDL) receptor-messenger RNA (mRNA), the catalytic activity and mRNA level of microsomal hepatic 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, the rate-limiting enzyme for de novo cholesterol synthesis, were significantly lower in the former (2.9 +/- 0.3 pmol/min/mg protein) than in the latter (5.1 +/- 0.6) (P < .0001). Biliary molar percentage of bile acids was significantly lower in the former (69.8 +/- 1.1%) than in the latter (75.2 +/- 1.5%) (P < .01). However, contrary to expectations, the catalytic activity and mRNA level of cholesterol 7 alpha-hydroxylase, the rate-limiting enzyme for bile acid synthesis, were significantly higher in the former (5.8 +/- 0.4 pmol/min/mg protein) than in the latter (3.7 +/- 0.6) (P < .01). The magnitude of the impaired gallbladder emptying (control subjects; 78.4 +/- 4% vs. CSs; 58 +/- 3%; P < .0005) together with the prolonged small intestinal transit (control subjects; 126 +/- 9 minutes vs. CSs; 198 +/- 9 minutes; P < .01) correlated significantly with the increased percentage of DC in bile. It is concluded that in cholesterol gallstone disease an increase of DC in bile, linked to an impaired gallbladder emptying together with a prolonged small intestinal transit, may play a significant role in downregulating de novo cholesterol synthesis but not bile acid synthesis in the liver.(ABSTRACT TRUNCATED AT 400 WORDS)

Primary dual defect of cholesterol and bile acid metabolism in liver of patients with intrahepatic calculi

BACKGROUND/AIMS

Intrahepatic calculi, which are characterized by cholesterol-rich pigment stones, are highly prevalent in East Asia. Their pathogenesis remains unknown. To elucidate the etiological factors underlying the formation of cholesterol-supersaturated bile, which leads to the formation of cholesterol-rich pigment stones cholesterol and bile acid de novo syntheses in the liver were studied.

METHODS

Liver specimens were assayed for the catalytic activities and steady-state messenger RNA levels of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase and cholesterol 7 alpha-hydroxylase.

RESULTS

The activity of HMG-CoA reductase, consistent with the messenger RNA level, was significantly higher in 13 patients with intrahepatic grown pigment stones (11.2 +/- 1.3 pmol.min-1.mg protein-1 [mean +/- SEM; P < 0.0001] for affected hepatic lobes and 13.4 +/- 1.7 [P < 0.0001] for unaffected ones [P < 0.0001]) than in 19 control subjects (6.4 +/- 0.4) and in 29 patients with gallbladder cholesterol stones (2.1 +/- 0.1). On the other hand, the activity of 7 alpha-hydroxylase, consistent with the messenger RNA level, was significantly lower in patients with intrahepatic brown pigment stones (2.8 +/- 0.5 pmol.min-1.mg protein-1 [P < 0.0001] for affected lobes and 2.6 +/- 0.5 [P < 0.0001] for unaffected ones) than in control subjects (6.0 +/- 0.6) and in patients with cholesterol stones (5.1 +/- 0.5).

CONCLUSIONS

In intrahepatic calculi, the formation of supersaturated bile and cholesterol-rich pigment stones may be attributed to the primary dual defect of up-regulated cholesterogenesis and down-regulated bile acid synthesis in the liver.

Randomized control trial of lipo-prostaglandin E1 in patients with acute liver injury induced by lipiodol-targeted chemotherapy

OBJECTIVE

The aim of this study was to prove whether lipo-prostaglandin E1 (PGE1)/glucagon insulin therapy combination could prevent the acute liver dysfunction induced by Lipiodol (iodized oil)-targeted chemotherapy for hepatocellular carcinoma.

METHODS

This study was a randomized control trial. Patients in two groups (groups A and B: n = 29) were each given an intravenous injection of 10 units of insulin and 1 mg glucagon every 12 hours for 1 week after Lipiodol-targeted chemotherapy. Patients in group B (n = 11) were each given an intravenous injection of 20 micrograms lipo-PGE1 every 12 hours over 1 week. Several items, including conventional liver function tests, were evaluated at the start of the study and on the days 1, 2, 4, 7, and 14 after Lipiodol-targeted chemotherapy.

RESULTS

Combined lipo-PGE1/glucagon-insulin therapy can prevent the elevation of serum ALT level and total bilirubin level after Lipiodol-targeted chemotherapy. In the group A (glucagon-insulin therapy only), the maximum level in the follow-up interval was statistically higher than that in the pretreatment level (p < 0.05), whereas there was no significant difference in group B (treated with combined glucagon-insulin therapy and lipo-PGE1). Changes of ALT level in group B tend to be lower than in group A; however, there was no significant statistical difference. There were few episodes of side effects in both groups.

CONCLUSION

Combined lipo-PGE1/glucagon-insulin therapy may be a safe and effective treatment for the prevention of acute hepatic failure.

[Dose-volume histogram analysis of patients with hepatocellular carcinoma regarding changes in liver function after proton therapy]

Seventy-five patients with hepatocellular carcinoma were treated with proton beams from 1983-1993 at the Proton Medical Research Center, University of Tsukuba. For the purpose of confirming the feasibility of proton therapy for hepatocellular carcinoma, we investigated the influence of proton therapy on liver function and also tried to evaluate the possibility of optimization using dose-volume histogram (DVH) analysis. The results indicated that proton therapy did not cause clinically symptomatic damage in liver function and the only notable change after proton therapy was the transient increase of transminase. DVH analysis showed that this transient increase of transaminase was well correlated to the normal tissue complication probability (NTCP). These results indicate that localized high dose radiation using proton beams is feasible for the treatment of liver cancers and optimization of this treatment may be possible using DVH analysis.

Increased bile acid concentration in liver tissue with cholesterol gallstone disease

Patients with cholesterol gallstone disease have a reduced pool of bile acids. Overly sensitive feedback inhibition of bile acid synthesis has been postulated to explain this size reduction. To test this hypothesis, hepatic bile acid concentration and the activity of cholesterol 7 alpha-hydroxylase, the rate-limiting enzyme for bile acid biosynthesis, were determined in ten patients with cholesterol gallstones and ten patients without gallstones. The bile acids present in liver tissue are the sum of those returning to liver and those newly synthesized in liver. If an overly sensitive feedback inhibition truly existed in our gallstone patients, a decreased concentration of hepatic bile acids would have been expected. However, patients with cholesterol gallstones had significantly higher total (143.3 +/- 25.5 vs 64.5 +/- 10.8 nmol/g liver, P < 0.01), chenodeoxycholic (64.1 +/- 9.9 vs 29.8 +/- 5.4, P < 0.01), deoxycholic (22.8 +/- 10.9 vs 2.0 +/- 0.7, P < 0.05), and ursodeoxycholic acid (6.2 +/- 1.4 vs 1.5 +/- 0.6, P < 0.01) concentrations than patients without gallstones. The activity of cholesterol 7 alpha-hydroxylase did not differ significantly between the two groups. Impaired hepatic transport or secretion of bile acids is strongly suspected in cholesterol gallstone patients. The findings of the present study showed no evidence of overly sensitive feedback inhibition of bile acid synthesis in cholesterol gallstone patients. Bile acid pool size may be affected by the inappropriate increase of hepatic bile acids rather than by overly sensitive feedback inhibition.

The relationship between pharmacokinetic behaviour of glycyrrhizin and hepatic function in patients with acute hepatitis and liver cirrhosis

The pharmacokinetic behavior of glycyrrhizin in four patients with acute hepatitis (hepatitis group) and six patients with liver cirrhosis (cirrhosis group) receiving chronically an IV administration of a 120 mg dose once a day or once every other day of glycyrrhizin was investigated. The plasma concentration of glycyrrhizin declined monoexponentially in both groups. The elimination half-life (t1/2) for glycyrrhizin in the hepatitis and cirrhosis groups varied significantly in the range of 2.7-7.6 h and 6.2-40.1 h, and the total body clearance (CLtot) in the range of 2.8-23.2 mL h-1 kg-1 and 1.4-12.9 mL h-1 kg-1, respectively. The t1/2 for glycyrrhizin in the hepatitis and the cirrhosis groups was about twice and eight times that in normal subjects, respectively, as reported previously, and CLtot values were about 0.7 and 0.23 times that in normal subjects, respectively. There was significant correlation between the CLtot and hepatic function (aspartate aminotransferase and alanine aminotransferase in serum) in both patient groups. With improvement of the liver function, the CLtot for glycyrrhizin increased from 2.8 ml h-1 kg-1 to 11.4 mL h-1 kg-1, and the t1/2 shortened from 7.6 h to 3.4 h. These findings indicated that the variation of pharmacokinetic behaviour of glycyrrhizin in both groups was closely related to the extent of the liver function.