Roger D. Soloway

Risk factors for gallbladder cancer. An international collaborative case–control study

Background. Gallbladder cancer has an unusual geographic and demographic distribution, suggesting many possible etiologies.

APRI : An easy and validated predictor of hepatic fibrosis in chronic hepatitis C

Goals To evaluate the aspartate aminotransferase/platelet ratio index (APRI) as a predictor of the presence or absence of significant fibrosis on liver biopsy of patients with chronic hepatitis C (HCV). Background The decision to treat HCV is often made on the basis of the presence or absence of significant fibrosis on the liver biopsy. Because liver biopsy is expensive and invasive a noninvasive marker to evaluate hepatic fibrosis would be useful. The APRI is an easy to calculate index that is one of several markers that have been proposed. Study We retrospectively reviewed the charts of 339 patients with chronic HCV who had liver biopsies from January 2000 to March 2003. We subsequently evaluated 151 patients receiving pretreatment evaluation liver biopsies who had serum aspartate aminotransferase, platelets, routine liver function tests, and demographic data obtained. All liver biopsies were staged by the Batts Ludwig criteria. Results The area under the curve of the receiver operator characteristics of the calculated APRI compared with the liver biopsy demonstrated that the fibrosis score was 0.889 in the prospective group and 0.790 in the retrospective group. To achieve predictive values of approximately 90%, useful cutoffs were found at 0.40 and 1.5 in the retrospective study, and 0.42 and 1.2 in the prospective study leaving intermediate zones of 58.9% and 41.1%, respectively. In the prospective group, 34 of 36 patients with a value of <0.42 were accurately predicted as having mild fibrosis, whereas 50 of 54 patients with a value >1.2 were accurately predicted to have significant fibrosis. Conclusions The APRI is a good estimator of hepatic fibrosis and was more accurate in a prospective group than a retrospective one. It potentially could be used to decrease the number of liver biopsies.

Portal Venous Thrombosis: Percutaneous Therapy and Outcome

PURPOSEnTo study the efficacy of percutaneous treatment for portal vein thrombosis (PVT).nnnMATERIALS AND METHODSnOf 20 patients who were evaluated for symptomatic portal occlusion, 14 were successfully treated with use of percutaneous techniques. In patients with noncavernomatous PVT (n = 15), the initial treatment was to increase portal output by creating a transjugular intrahepatic portosystemic shunt (TIPS), which was successful in 12 cases. Methods to decrease arterial input to the portal system (hepatosplenic arterial embolization) were used as primary therapy in two patients and in an additional two patients with continued symptoms, despite a functioning TIPS.nnnRESULTSnAll TIPS survivors had patent shunts, although patients with complete PVT required more frequent revisions compared to patients with nonocclusive PVT. Hepatosplenic arterial embolization controlled symptoms in the four patients who were treated, but both patients with patent TIPS died of liver failure after embolization. Of the 14 patients treated, eight died at a mean of 6.2 months (six from hepatoma).nnnCONCLUSIONnTIPS is effective in patients with noncavernomatous PVT, although patients with complete thrombosis experience recurrent shunt occlusions and also may develop hepatoma. If TIPS fails, or if symptoms recur, hepatosplenic arterial embolization may be an option.

Clostridium difficile diarrhea in patients with AIDS versus non-AIDS controls. Methods of treatment and clinical response to treatment.

We reviewed the hospital charts of 17 patients with AIDS and Clostridium difficile diarrhea to determine antibiotic use before C. difficile infection, methods of treatment for C. difficile diarrhea, and response of diarrhea to treatment. Left shift and total white blood cell count before and after treatment for C. difficile were also determined. Non-HIV-infected patients with C. difficile diarrhea served as controls. In the patients with AIDS, resolution of diarrhea was noted in 15 (88%) patients. In 25 (76%) control patients, diarrhea resolved with treatment. The patients with AIDS also had a significant decrease (p < 0.05) in left shift in white blood cell count with treatment; the controls did not. Our study therefore suggests that C. difficile diarrhea is at least as likely to resolve with antibiotic therapy in patients with AIDS as it is in those with the non-AIDS-related disorder. We also found that patients with AIDS and C. difficile diarrhea are more likely than patients without AIDS to have a decreased left shift in white blood cell count after antibiotic therapy.

A spectroscopic study of pigment gallstones in China

Spectroscopic studies of various types of gallstones carried out in China are reviewed. Three basic classes of gallstones are surveyed: cholesterol stones, brown pigment stones, and black pigment stones. The emphasis of this review is on brown gallstones. The primary spectroscopic methods used in the studies surveyed are Fourier transform infrared absorption and Fourier transform Raman scattering. Chemical components studied in gallstones include cholesterol, bile pigments, glycoproteins, proteins, bilirubin metal complexes, and salts of calcium and other metals. Further studies are needed characterize the relationship of these components to more complex features of gallstones.

Calcium carbonate in cholesterol gallstones : polymorphism, distribution, and hypotheses about pathogenesis

This study of sets of cholesterol gallstones collected consecutively from 222 patients in La Paz, Bolivia, and Mexico City, Mexico, has developed a reliable infrared (IR) spectroscopic method for the detection of calcium carbonate in cholesterol gallstones and provided the basis for simultaneous identification of each of its three polymorphs: calcite, vaterite, and aragonite. The peaks in the 854 to 876 cm−1 region demonstrated 98% sensitivity and specificity for carbonate detection. As little as 3% carbonate by weight could be detected using these peaks. The overall incidence of carbonate was 19% in these populations containing a high proportion of Amerinds. Infrared microspectroscopy of 10 to 50 μm particles, dissected from stones, allowed a ring‐by‐ring examination of 11 carbonate‐containing stones. It was determined that different carbonate polymorphs, when present in the same gallstone, almost always occurred in separate rings. In approximately half of the gallstones, different polymorphs were present in successive layers in the same stone, indicating that conditions governing stone growth changed cyclically. Carbonates were usually precipitated in peripheral layers rather than in the center, supporting the theory that formation of calcium carbonates may be related to episodes of intermittent obstruction of the cystic duct, as opposed to being a major factor in stone nidation. (Hepatology 1995;22:488–496.)

Hepatic Perfusion before and after the Transjugular Intrahepatic Portosystemic Shunt Procedure: Impact on Survival

PURPOSEnThis study correlates transjugular intrahepatic portosystemic shunt (TIPS) mortality with flow patterns in the cirrhotic liver.nnnMATERIALS AND METHODSnTwenty-seven TIPS patients and 10 control subjects were used for this study. The authors evaluated hepatic perfusion with venous injections of Tc-99m pertechnetate before and after TIPS. Hepatic time-activity curves were analyzed for type and amount of liver perfusion. These parameters were correlated with survival for a mean follow-up of 18 months.nnnRESULTSnThe mean arterial contribution to liver blood flow was 25.4% in the normal control patients, 39.9% in patients prior to TIPS, and increased to 48.3% after TIPS. Although the proportion of arterial supply to the cirrhotic liver varied widely, TIPS mortality did not correlate with the preprocedure hepatic artery/portal venous perfusion ratio. However, patients with both an arterialized flow pattern and low total hepatic perfusion had higher mortality, with a mean survival of 2 months compared to patients with a more favorable perfusion profile (mean survival, 28.4 months).nnnCONCLUSIONSnThe proportion of arterial perfusion to the liver before TIPS did not affect survival. However, patients with a combination of reduced total hepatic perfusion and an arterial flow pattern had poorer survival, suggesting that both the quantity and quality of hepatic perfusion predicts TIPS outcome.

Investigation of Normal and Malignant Tissue Samples from the Human Stomach Using Fourier Transform Raman Spectroscopy

Fourier transform (FT) Raman studies of 40 tissue samples from the human stomach, including 22 normal and 18 malignant tissue samples, were performed. These stomach tissue samples had been classified as normal or malignant on the basis of pathological studies and biopsy detection. The results indicate that a series of major bands in the FT-Raman spectrum can be used to distinguish the malignant tissue from the normal tissue. Subtraction spectra support the result of the spectroscopic identification. Statistical analysis is also in agreement with the FT-Raman measurements.

A New Mechanism of Raman Enhancement and its Application

Strong electronic Raman bands corresponding to the transition between 4I9/2 and 4I11/2 manifolds of Nd3+, caused by a Raman-enhancement effect, are observed in the FT-Raman spectrum of Nd2O3. Neither resonance enhancement (RR) nor surface enhancement (SERS) accounts for the Raman enhancement observed here. We propose a new mechanism of Raman enhancement called the feed-back mechanism. A YAG laser excites the final state of the Raman transition (4I11/2 of Nd3+) to the 4F3/2 state and causes a significant decrease in the population of Nd3+ at the 4I11/2 state. This causes the population ratio of Nd3+ at 4I9/2 and 4I11/2 to deviate from the value required by Boltzmanns law. To restore equilibrium, Raman scattering is enhanced so that more Nd3+ ions are brought from the 4I9/2 state to the 4I11/2 state. This hypothesis gets support from the temperature-variable FT-Raman spectroscopic results. Additionally, obvious differences between the Stokes and anti-Stokes Raman spectrum of Nd3+ provide further evidence to support the feed-back mechanism. The Raman-enhancement effect confers on the electronic Raman bands a special ability to reflect the variation of coordinated structure around metal ions. The structural variations in polymer-metal ion composites and biomineralization systems have been investigated by using the electronic Raman bands.

Normal coordinate analysis of bilirubin vibrational spectra: effects of intramolecular hydrogen bonding

Abstract Normal coordinate analyses are presented for half-bilirubin molecules. Calculations for the Aue5f8B pyrromethenone include intramolecular hydrogen bonds, while those for the Cue5f8D chromophore exclude intramolecular hydrogen bonds. Valence force-field parameters have been optimized to correlate closely with the IR and Raman spectra of the target molecules. The results of the calculations are compared with the spectra of bilirubin IXa and various model compounds in the solid state and solution.