Suppression of hepatitis C virus by the flavonoid quercetin is mediated by inhibition of NS3 protease activity

Phytochemicals exert antiviral activity and may play a potential therapeutic role in hepatitis C virus (HCV) infection. In this work, we aimed to isolate NS3 inhibitors from traditional Indian medicinal plants that were found, in our earlier study, to inhibit HCV NS3 protease activity and to evaluate their potential to inhibit HCV replication. A potent inhibitory effect of NS3 catalytic activity was obtained with Embelia ribes plant extracts. Quercetin, a ubiquitous plant flavonoid, was identified as the active substance in the fractioned extract. It was found to inhibit NS3 activity in a specific dose-dependent manner in an in vitro catalysis assay. Quercetin inhibited HCV RNA replication as analysed in the subgenomic HCV RNA replicon system. It also inhibited HCV infectious virus production in the HCV infectious cell culture system (HCVcc), as analysed by the focus-forming unit reduction assay and HCV RNA real-time PCR. The inhibitory effect of quercetin was also obtained when using a model system in which NS3 engineered substrates were introduced in NS3-expressing cells, providing evidence that inhibition in vivo could be directed to the NS3 and do not involve other HCV proteins. Our work demonstrates that quercetin has a direct inhibitory effect on the HCV NS3 protease. These results point to the potential of quercetin as a natural nontoxic anti-HCV agent reducing viral production by inhibiting both NS3 and heat shock proteins essential for HCV replication.

Cell transformation induced by hepatitis C virus NS3 serine protease

Persistent infection with hepatitis C virus (HCV) may lead to hepatocellular carcinoma (HCC). It has been suggested that HCV-encoded proteins are directly involved in the tumorigenic process. The HCV nonstructural protein NS3 has been identified as a virus-encoded serine protease. To study whether HCV NS3 has oncogenic activity, nontumorigenic rat fibroblast (RF) cells were stably transfected with an expression vector containing cDNA for the NS3 serine protease (nucleotides 3356-4080). The NS3 serine protease activity was determined in the transfected cells. The transfected cells grew rapidly and proliferated serum independently, lost contact inhibition, grew anchorage independently in soft agar and induced significant tumour formation in nude mice. Cells transfected with an expression vector containing a mutated NS3 serine protease (serine 139 to alanine at the catalytic site) showed no transforming abilities; their growth was dependent on serum and they did not grow anchorage independently in soft agar. Moreover, cells transfected with the NS3 serine protease and treated with the chymotrypsin inhibitors TPCK and PMSF (a serine protease inhibitor) lost their transforming feature. These results suggest that the NS3 serine protease of HCV is involved in cell transformation and that the ability to transform requires an active enzyme.

The addition of mycophenolate mofetil for suppressing hepatitis B virus replication in liver recipients who developed lamivudine resistance--no beneficial effect

BACKGROUND

Mycophenolate mofetil is used as an immunosuppressive agent in liver transplant recipients. Its active compound, mycophenolic acid, also inhibits the replication of Epstein-Barr virus and human immunodeficiency virus. Based on a study indicating the effectiveness of mycophenolate mofetil on hepatitis B virus (HBV) replication in infected human hepatocyte cells in culture, we examined the efficacy of mycophenolate mofetil in suppressing HBV replication in lamivudine-resistant liver allograft recipients with recurrent HBV infection.

METHOD

The study population included four liver allograft recipients (three males, one female), median age 51 years (range 41-57 years), with recurrent HBV infection who proved to be resistant to lamivudine. All received standard maintenance immunosuppression therapy. Median pretreatment serum alanine aminotransferase level was 75 mu/L (range 39-182 mu/L) and HBV DNA level (quantitative dot blot), 70 pg/ml (range: 10-5,000 pg/ml). Mycophenolate mofetil, 1.0 g p.o. twice daily, was administered for 8 weeks, concomitant with a reduction in the maintenance corticosteroid and cyclosporine doses.

RESULTS

After mycophenolate mofetil was administered, the serum alanine aminotransferase level increased in two patients, did not change in one, and decreased in one. Serum HBV DNA levels increased in three patients and decreased (nonsignficantly) in only one patient. Two patients complained of abdominal pain and nausea.

CONCLUSIONS

Mycophenolate mofetil at the dosage used is not effective in suppressing HBV replication after liver transplantation.

Mutations at vicinity of catalytic sites of hepatitis C virus NS3 serine protease gene isolated from hepatocellular carcinoma tissue

The mechanism of hepatitis C virus (HCV) -induced hepatotocellular carcinoma (HCC) is still unknown, but in vitro studies clearly suggest that HCV proteins exert a direct effect on liver carcinogenesis. HCV NS3 serine protease is known to play a key role in the life cycle of the virus and may interact with the host cellular regulatory proteins. The aim of the present study was to conduct a genetic analysis of the HCV NS3 gene coding for the serine protease isolated from serum, tumor, and nontumor tissue of HCC patients. RNA was extracted and HCV cDNA was amplified by nested reverse transcriptase-polymerase chain reaction (RT-PCR). Sequence comparison yielded unique changes at the vicinity of the catalytic sites of the NS3 clones isolated only from HCC tissue. These changes included the insertion of a "large" and charged amino acid, substitution of a polar with a hydrophobic amino acid, and substitution of a charged with a polar amino acid. Those changes affect the electrostatic charge around the active site, and thus the activity and substrate specificity of the serine protease. This is the first study to define significant amino acid changes at the catalytic domain of the NS3 serine protease gene isolated from HCC tissue.

Information processing with population codes

Information is encoded in the brain by populations or clusters of cells, rather than by single cells. This encoding strategy is known as population coding. Here we review the standard use of population codes for encoding and decoding information, and consider how population codes can be used to support neural computations such as noise removal and nonlinear mapping. More radical ideas about how population codes may directly represent information about stimulus uncertainty are also discussed.

Fulminant non--A-G viral hepatitis leading to liver transplantation

BACKGROUND

All hepatotropic viruses are known to cause fulminant hepatic failure (FHF). However, in 30% to 40% of patients with FHF, the precise cause remains unknown. We aimed to better define this subgroup.

METHODS

We evaluated the clinical course and outcome of 7 patients admitted during a 22-month period with fulminant viral hepatitis leading to liver transplantation; none had serologic or molecular evidence of hepatitis A, B, C, D, E, or G viral infection, thus the term non-A-G viral hepatitis. All known etiologies of FHF were excluded.

RESULTS

All patients had prodromal symptoms suggestive of viral causes. Mean age was 30 years. The interval between onset of jaundice and appearance of encephalopathy was 23 days (range, 4-50 days). Five patients had grade III/IV encephalopathy. Serum alanine aminotransferase levels showed a single peak of activity. The duration between first symptoms and liver transplantation was 28 days (range, 12-71 days). Results of histological study of the explanted liver showed submassive (4 patients) or massive (3 patients) hepatocyte necrosis. In all patients, results of polymerase chain reaction analysis did not detect hepatitis B virus DNA, hepatitis C virus RNA, or hepatitis G virus RNA in the explanted liver. After transplantation, 2 patients showed (6 months later) increased liver enzyme levels of undetermined cause, and results of a liver biopsy showed mild lobular hepatitis; 1 patient had lymphoproliferative disorder (Epstein-Barr virus-originated); and 1 patient, aplastic anemia, which is known to be associated with seronegative viral hepatitis. The latter patient died, whereas the other 6 patients are alive (survival rate, 86%).

CONCLUSIONS

Our patients with non-A-G viral hepatitis had a severe acute onset with progressive FHF requiring liver transplantation. There is some suggestion of recurrent viral disease after transplantation implicating other unknown viruses in the etiology.

Streptozotocin and alloxan-based selection improves toxin resistance of insulin-producing RINm cells

The aim of our study was to develop a method for selection of subpopulations of insulin producing RINm cells with higher resistance to beta cell toxins. Cells, resistant to streptozotocin (RINmS) and alloxan (RINmA), were obtained by repeated exposure of parental RINm cells to these two toxins, while the defense capacity was estimated by the MTT colorimetric method, and [3H]-thymidine incorporation assay. We found that RINmS and RINmA displayed higher resistance to both streptozotocin (STZ) and alloxan (AL) when compared to the parental RINm cells. In contrast, no differences in sensitivity to hydrogen peroxide were found between toxin selected and parental cells. Partial protection from the toxic effect of STZ and AL was obtained only in the parental RINm cells after preincubation of cells with the unmetabolizable 3-O-methyl-glucose. The possibility that GLUT-2 is involved in cell sensitivity to toxins was confirmed by Western blot analysis, which showed higher expression of GLUT-2 in parental RINm compared to RINmS and RINmA cells. In addition to the higher cell defense property evidenced in the selected cells, we also found higher insulin content and insulin secretion in both RINmS and RINmA cells when compared to the parental RINm cells. In conclusion, STZ and AL treatment can be used for selection of cell sub-populations with higher cell defense properties and hormone production. The different GLUT-2 expression in parental and resistant cells suggest involvement of GLUT-2 in mechanisms of cell response to different toxins.

Association of lamivudine resistance in recurrent hepatitis B after liver transplantation with advanced hepatic fibrosis

BACKGROUND

Orthotopic liver transplantation (OLT) in patients with hepatitis B virus (HBV) infection is known to be associated with a high recurrence rate and poor prognosis. Lamivudine, a nucleoside analogue, is a potent inhibitor of HBV replication, but it is associated with a 14-39% rate of resistance.

METHODS

We report on four patients who underwent OLT for HBV infection. In all cases, the HBV infection recurred in the grafted liver and was treated with lamivudine (100 mg daily) on a compassionate-use basis. The patients were monitored closely for serum liver enzymes, hepatitis B surface antigen and HBV DNA (by hybridization). Liver biopsy was performed before and after lamivudine therapy. HBV DNA was amplified from serum for each patient and sequenced through a conserved polymerase domain, the tyrosine-methionine-aspartate-aspartate (YMDD) locus.

RESULTS

All four patients exhibited lamivudine resistance 9-20 months after initiation of the drug. In all patients with a clinically mild disease, liver histology findings (12-24 months after lamivudine therapy) showed progressive fibrosis as compared to biopsies performed before lamivudine therapy, with a significant increase (> or =2 points) in the Knodell score in three patients. Moreover, two patients exhibited worsening of the necroinflammatory process. A mutation at the YMDD motif of the HBV polymerase gene was detected in all cases.

CONCLUSIONS

Lamivudine resistance frequently occurs in patients with recurrent HBV infection after OLT and is associated with advanced hepatic fibrosis and necroinflammatory process. A combination of antiviral therapies may be necessary.

Nitric oxide metabolites in decompensated liver cirrhosis

High levels of nitric oxide are thought to be the cause of some of the complications associated with decompensated end-stage liver disease. To assess nitric oxide metabolism in cirrhotic patients, we measured the levels of nitric oxide metabolites (nitrosohemoglobin, methemoglobin, nitrate, and nitrite) in normal subjects, in patients with decompensated cirrhosis, in patients with renal failure (model for impaired NO metabolites excretion), and in patients with mononitrates-treated anginal syndrome (model for exogenous nitric oxide). When compared to controls, patients with decompensated cirrhosis exhibited elevated levels of nitrate only. A significant increase of nitrate was also noted in patients receiving exogenous nitrates, whereas patients with impaired excretion had significantly elevated levels of both nitrite and nitrate. In conclusion, nitric oxide metabolism in patients with decompensated cirrhosis is similar to that of patients receiving nitric oxide from an exogenous source. Renal impairment, whether alone or associated with cirrhosis, causes a change in nitric oxide metabolism. These findings may have clinical implications for nitrates treatment in patients with decompensated cirrhosis.

Efficacy of lamivudine in patients with hepatitis B virus precore mutant infection before and after liver transplantation

OBJECTIVE

Hepatitis B virus (HBV) precore mutant infection is associated with a more severe liver disease and a poorer response to interferon. We evaluated the efficacy and tolerance of lamivudine to induce complete and sustained suppression of viral replication in seven patients infected with HBV precore mutant (HBeAg-/HBeAb+/HBV DNA+) (in three patients mutation at codon 1896 was detected by direct sequencing).

METHODS

Of the seven patients, five had decompensated HBV cirrhosis in a replicative phase and were liver transplant candidates (Group A) and two patients underwent orthotopic liver transplantation (OLT) for HBV liver cirrhosis and developed recurrent HBV infection in the grafted liver (Group B). Lamivudine 100 mg daily was administered orally for a period of 6-75 wk.

RESULTS

After 6-8 wk lamivudine therapy was well tolerated and successfully suppressed HBV replication to an undetectable serum level of HBV DNA by polymerase chain reaction in six patients. In Group A, two patients underwent successful OLT with no evidence of HBV reinfection 2-14 months later. Lamivudine was continued after OLT with no episodes of rejection. Three patients died before a suitable liver could be found (one remained serum HBV DNA+ after 6 wk of lamivudine therapy). In Group B, 9-14 months after lamivudine therapy both patients developed lamivudine resistance (increased liver enzymes, reappearance of serum HBsAg and HBV DNA [by hybridization]). In both patients liver histology had progressed and in both, mutation at codon 552 of the HBV polymerase gene was detected.

CONCLUSIONS

Lamivudine is well tolerated in patients with decompensated liver cirrhosis due to HBV precore mutant infection who are liver transplant candidates. In four patients (80%) potent suppression of viral replication was detected, allowing OLT to be performed. However, post-OLT, a resistant mutant developed under lamivudine therapy. Combination therapy with other antiviral agents should be evaluated to discourage the emergence of lamivudine-resistant mutants.

Viremia, genetic heterogeneity, and immunity to hepatitis G/GB-C virus in multiply transfused patients with thalassemia

BACKGROUND

Thalassemia patients are at high risk for posttransfusion hepatitis. Hepatitis G virus (HGV) has been suspected of being responsible for acute and chronic hepatitis.

STUDY DESIGN AND METHODS

The prevalence of HGV infection, its possible association to liver disease, the genetic heterogeneity among the various HGV isolates, and immunity to HGV were studied in 36 thalassemia patients with reverse transcriptase-polymerase chain reaction assay and sequence analysis.

RESULTS

HGV RNA was detected in seven patients (19.4%), only two of whom had evidence of hepatitis C virus infection as well. Sequence analysis of the NS3 gene from isolates of the five patients infected with HGV alone revealed 84.7 to 90.9 percent homology at the nucleotide level. Prolonged HGV viremia was not associated with significant liver enzyme elevation. All five patients were chronically infected with the same viral strain. E2 antibodies were detected in 57 percent of the HGV-nonviremic patients and in only 1 of 7 viremic patients.

CONCLUSION

HGV is associated with persistent viremia but not with significant biochemical evidence of liver damage. There is some genetic heterogeneity among HGV isolates from thalassemia patients in Israel.

Treatment of colorectal liver metastases by cryotherapy

One hundred fifty-eight procedures were performed on 136 patients with unresectable hepatic metastases using hepatic cryotherapy to ablate the tumors. The median age was 62 years. Patients included 90 males and 46 females. Fifty-eight patients had synchronous metastases, 55 had bilobar lesions, and 90 had precryo chemotherapy. Median preoperative carcinoembryonic antigen (CEA) level was 14.4 ng/dl. The numbers of lesions treated, frozen, and resected were two and one. Median survival of all patients was 30 months. Survival for 39 patients was 37 months. Patients with a CEA level > 100 ng/dl had a statistically worse survival rate than those with a level < 100 ng/dl (P < .001). Twenty patients underwent recryotherapy with median survival of 34 months. Recurrent disease developed in 78% of patients--82% of the patients developed liver recurrence. Complication rates were comparable to liver resection. Operative mortality was 3.7%. Hepatic cryotherapy is effective and safe in treating colorectal hepatic metastases under ultrasound guidance.

Infectious complications of hepatic cryosurgery

Hepatic cryosurgery is a novel procedure for patients with metastatic liver disease. To date, no reviews of the infectious complications of this procedure have been published. One hundred and fifty patients underwent 158 hepatic cryosurgical procedures at Allegheny General Hospital (Pittsburgh) from November 1987 through July 1995. Gastrointestinal malignancies accounted for 93% of the underlying diagnoses. The following 12 infections were directly related to the cryosurgical procedure: hepatic abscess (six), intraperitoneal abscess (three), ascending cholangitis (two), and an intrahepatic device (Infusaid; Strato/Infusoid, Norwood, MA) infection (one). Enterococcus was the most commonly isolated organism. Seven of the 12 infections were polymicrobial. The patients who developed infections had longer hospital stays (26 days vs. 13 days) and had more days of fever (6.5 days vs. 2.3 days). than those who did not develop infections. If perioperative manipulation of the biliary tree is avoided, the infection rate in patients who undergo hepatic cryosurgery may be decreased even further. Overall, cryoablation of the liver is not related to an increased risk of infection.

Hepatic cryosurgery in the treatment of unresectable metastases

The treatment of unresectable hepatic metastases has generally been limited to systemic or intra-arterial chemotherapy. Cryosurgery has the advantage of potentially ablating such unresectable tumours. From November 1987 to August 1994, 140 patients underwent 155 procedures using hepatic cryosurgery with and without resection for documented metastatic disease. Intra-operative ultrasound was used for monitoring the freezing zone. The tumours were frozen using liquid nitrogen cooled to -196 degrees C for 15 min. The median number of lesions treated was three. Median hospital stay was 10 days. The operative mortality was 4%. Complications included coagulopathy, hypothermia, myoglobinuria, pleural effusions, ATN and infection. The median survival for all patients was 22 months. Of those patients followed for more than 2 years, the median survival was 25 months. Of the 65 patients that are still alive, the median follow-up is 27 months.

Hepatic cryosurgery in treating colorectal metastases

BACKGROUND

The purpose of this study was to determine the effectiveness of cryosurgery as an adjunct to resection in treating patients with hepatic metastases from colorectal adenocarcinoma.

METHODS

Forty-seven patients with documented metastases limited to the liver from colorectal adenocarcinoma were treated with cryosurgery with or without resection from November 1987 to February 1992 and were followed until February 1994. Intraoperative ultrasound was used to map the lesions and place the cryoprobes. Each lesion was frozen to -196 degrees centigrade for 15 minutes, thawed for 10 minutes, and frozen again for 15 minutes. Follow-up computed tomographic scans were obtained before hospital discharge and 6 months and 1 year after cryosurgery. Carcinoembryonic antigen levels were obtained monthly.

RESULTS

Thirty-one males and 16 females, with a median age of 63 years, were treated. The median hospital stay was 10 days, and follow-up ranged from 24 to 57 months, with a median follow-up of 26 months. The actual survival at 24 months was 62%. Eleven percent of these patients had no evidence of disease at a median follow-up of 30 months. Complications included myoglobinuria, coagulopathy, pleural effusions, and bile duct injuries. Two patients (4%) died because of multisystem organ failure with irreversible coagulopathies.

CONCLUSIONS

Cryosurgical ablation increases the number of patients with liver metastases who potentially can become disease free. However, the effect on overall survival will require a longer follow-up period.

Crystal structure of a catalytic antibody Fab with esterase-like activity

BACKGROUND

Antibodies with catalytic properties can be prepared by eliciting an antibody response against 'transition state analog' haptens. The specificity, rate and number of reaction cycles observed with these antibodies more closely resemble the properties of enzymes than any of the many other known enzyme-mimicking systems.

RESULTS

We have determined to 3 A resolution the first X-ray structure of a catalytic antibody Fab. This antibody catalyzes the hydrolysis of a p-nitrophenyl ester. In conjunction with binding studies in solution, this structure of the uncomplexed site suggests a model for transition state fixation where two tyrosines mimic the oxyanion binding hole of serine proteases. A comparison with the structures of known Fabs specific for low molecular weight haptens reveals that this catalytic antibody has an unusually long groove at its combining site.

CONCLUSION

Since transition state analogs contain elements of the desired product, product inhibition is a severe problem in antibody catalysis. The observation of a long groove at the combining site may relate to the ability of this catalytic antibody to achieve multiple cycles of reaction.

Differences in the biochemical properties of esterolytic antibodies correlate with structural diversity

A prerequisite to the design and engineering of catalytic antibodies is the knowledge of their structure and in particular which residues are involved in binding and catalysis. We compared the structure and catalytic properties of a series of six monoclonal antibodies which were all raised against a p-nitrophenyl (PNP) phosphonate and which catalyze the hydrolysis of p-nitrophenyl esters. Three of the antibodies (Group I) have similar light and heavy chain variable regions. The other three antibodies have similar VL regions of which two (Group II) have VH regions from the MOPC21 gene family and the remaining one (Group III) a VH from the MC101 gene family making a total of three different groups based on their V region sequences. The structural division into groups is paralleled by the differences in binding constants to hapten analogs, substrate specificity and the susceptibility of the catalytic activity of the antibodies to chemical modification of tryptophan and arginine residues. The relative binding of a transition state analog to the binding of substrate is much higher for the Group I antibodies than for the other groups. Only the Group I antibodies can catalyze the hydrolysis of a carbonate substrate. However all of the antibodies lose catalytic activity upon specific tyrosine modification which highlights the importance of tyrosine in the active site of the antibodies. Thus, antibodies raised against a single hapten can give antibodies with different structures, and correspondingly different specificities and catalytic properties.

Cryosurgery of liver cancer

Cryosurgery, the in situ destruction of tissue using subzero temperatures, has been used to treat hepatic metastases. Because it is a focal treatment, cryosurgery can be used in patients with unresectable lesions due to location (next to major blood vessels) or multiplicity. In this study, 57 patients with unresectable hepatic metastases were treated with cryosurgery (with at least a 6-month follow-up). The number of lesions treated ranged from 1-16 with a mean of 4.6. Forty-three patients (73%) had bilobar disease, while 25 patients (42%) were treated with a combination of resection and cryosurgery. The disease-free survival rate (patients with normal computed tomography [CT] scans and carcinoembryonic antigen [CEA] levels) was 27% with a mean follow-up of 21 months. This is comparable to other hepatic cryosurgery studies that have found survival rates of 25-37.5%. Although the results are still short-term, this study indicates that hepatic cryosurgery offers the hope of long-term survival in patients with unresectable hepatic metastases.

Hepatic cryosurgery with and without the Bair Hugger

Hypothermia is a significant clinical problem during hepatic cryosurgery, which at times causes the procedure to be halted until the patient's body temperature can be raised. This study examines the effects of the Bair Hugger (a warming device) on body temperature during hepatic cryosurgery. Twenty-eight cases of hepatic cryosurgery were performed without the Bair Hugger, while 44 cases included the Bair Hugger. The lowest mean temperature was significantly lower in the group without the Bair Hugger (34.2 degrees C vs. 35.3 degrees C; P < 0.0001). In addition, this group showed a significantly greater mean change in temperature during the procedure (1.81 degrees C vs. 0.73 degrees C; P < 0.0001). No patient in the Bair Hugger group reached the point of clinically significant hypothermia. In conclusion, the Bair Hugger is safe and very effective in regulating body temperature and it is an essential piece of equipment performing hepatic cryosurgery.

Ultrasound-guided hepatic cryosurgery in the treatment of metastatic colon carcinoma. Preliminary results

Cryosurgery, the in situ freezing of cancer, has been proposed in the past as a possible treatment for unresectable hepatic tumors. Its advantage lies in the fact that it is a very focal treatment sacrificing less normal tissue than surgical resection, allowing treatment of multiple lobes. Because cryosurgery does not affect large vessels, tumors in difficult locations, such as adjacent to the inferior vena cava (IVC), can be treated. With the use of intraoperative ultrasound to place the cryoprobes and monitor the freezing process, 18 patients with unresectable metastatic colon carcinoma confined to the liver were treated. Of the 18 patients treated, 4 (22%) are in complete remission as determined by computed tomography (CT) scans and carcinoembryonic antigen (CEA) levels, with a mean follow-up of 28.8 months. Four patients (22%) were not adequately treated at the time of cryosurgery. The number of lesions frozen in each patient ranged from 1 to 12, with a mean of 6 lesions. Fourteen patients had bilobar disease; three patients had previous right lobectomies with recurrences in their remaining left lobes prior to cryosurgery, and one patient had unilobar disease. Mean survival of the 14 cases with recurrence was 21.4 months, with 2 of the 14 still alive. Ultrasound-guided hepatic cryosurgery appears to be an effective treatment for metastatic colon carcinoma to the liver that is unresectable (including patients with bilobar and multiple lesions). These preliminary results indicate that the procedure warrants further study.

Hematologic complications of gastric bypass for morbid obesity

Of 530 patients who have had a gastric bypass operation for morbid obesity at Allegheny General Hospital, 41 had decreases in serum iron, vitamin B12, and/or folate levels. These abnormalities were detected eight months to eight years (median, two years) after the operation. The hemoglobin level ranged from 7.4 to 14.1 gm/dl at the time of detection, and mean corpuscular volume (MCV) ranged from 58 to 119 cu microns. The most common problem was combined iron and vitamin B12 deficiencies. Physicians should be aware that folate, vitamin B12, and iron deficiencies occur after gastric bypass, though the time to development is variable. Hemoglobin level and MCV are not predictive of these deficiencies.

Type B hepatitis after needle-stick exposure: prevention with hepatitis B immune globulin. Final report of the Veterans Administration Cooperative Study

Hepatitis B immune globulin (HBIG) and immune serum globulin (ISG) were examined in a randomized, double-blind trial to assess their relative efficacies in preventing type B hepatitis after needle-stick exposure to hepatitis B surface antigen (HBsAG)-positive donors. Clinical hepatitis developed in 1.4% of HBIG and in 5.9% of ISG recipients (P = 0.016), and seroconversion (anti-HBs) occurred in 5.6% and 20.7% of them respectively (P less than 0.001). Mild and transient side-effects were noted in 3.0% of ISG and in 3.2% of HBIG recipients. Available donor sera were examined for DNA polymerase (DNAP) and e antigen and antibody (HBeAg; anti-HBE). Both DNAP and HBeAg showed a highly statistically significant correlation with the infectivity of HBsAg-positive donors. Hepatitis B immune globulin remained significantly superior to ISG in preventing type B hepatitis even when the analysis was confined to these two high-risk subgroups. The efficacy of ISG in preventing type B hepatitis cannot be ascertained because a true placebo group was not included.

A randomized, double blind controlled trial of the efficacy of immune serum globulin for the prevention of post-transfusion hepatitis. A Veterans Administration cooperative study

A double blind, randomized, controlled trial has been conducted in 11 Veterans Administration hospitals during a 49-month period to compare the relative efficacies of immune serum globulin (ISG) and an albumin placebo for the prevention of post-transfusion hepatitis (PTH). A total of 2204 patients, of whom 1094 received ISG, participated in the study. The results indicate that ISG significantly reduced the incidence of icteric type non-B hepatitis only (inferred to be also type non-A hepatitis). Adverse reactions were rare, and the ISG did not significantly alter the incubation period or duration of the disease. The data suggest, however, that a similar reduction in type non-A, non-B hepatitis would have occurred had commercial blood been excluded from use. Analysis of the 241 patients who developed hepatitis indicates that type B hepatitis constituted less than 20% of the cases each year of the study. Furthermore, the efficacy of the ISG, manufactured in 1944, against apparent type non-A, non-B hepatitis suggests that this overlooked disease has existed from at least that time. Host- and transfusion-related factors that might have modified the development of PTH were examined. The use of commercial blood was observed to be the most important risk factor. It is concluded that the PTH incidence can be most effectively reduced by eliminating commercial donor blood, and continuing to screen volunteer donors for hepatitis B surface antigen (HBsAg) by sensitive procedures. Of prime importance is the need to define the agent(s) responsible for type non-A, non-B hepatitis.

Efficacy of hepatitis B immune serum globulin after accidental exposure. Preliminary report of the Veterans Administration Cooperative Study

A randomised, double-blind, controlled trial has been undertaken to compare the efficacy of hepatitis B immune globulin (H.B.I.G.) with that of immune serum globulin (I.S.G.) for the prophylaxis of viral hepatitis. Participants in the trial were individuals exposed accidentally to material infectious for hepatitis (primarily viral B hepatitis). Preliminary evaluation of the first 302 of the 561 individuals entered into the study indicates that H.B.I.G. significantly reduced the frequencies of both clinical and subclinical hepatitis during the first 3--4 months after the injection. Less than 10% of H.B.I.G. recipients had detectable anti-HBs at the sixth month after the injection, suggesting that H.B.I.G. might need to be given every 3--4 months to continually exposed individuals. Further long-term evaluation is required in order to define more clearly those most likely to benefit from H.B.I.G.

Hemodynamics of the isolated perfused pig liver: metabolism according to routes of perfusion and rates of flow

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