Hepatitis C virus and other risk factors in hepatocellular carcinoma.

UNLABELLED: Hepatocellular carcinoma (HCC) increased in Egypt in the past years, becoming the most common cancer among men. Hepatitis B virus (HBV) and hepatitis C virus (HCV) are the known primary risk factors for HCC. This study describes the viral profile of HCC in a predominantly rural area in Egypt. We included 148 HCC cases and 148 controls from the Tanta Cancer Center and the Gharbiah Cancer Society in the Nile delta region. Serological (ELISA) and molecular (PCR) analysis for HBV and HCV infection were performed on plasma samples from each subject. Epidemiologic, environmental, and medical histories were collected by interviewing of subjects. Around 90.5% of cases and controls were from rural areas. HCV infection was high in both cases and controls (89.2% and 49.3%, for cases and controls respectively by serology). HCV was the most important HCC risk factor [OR 9.7 (95% CI: 3.3-28.0, P <0.01)], and HBV infection showed marginal tendency of increased risk [OR 5.4 (95% CI: 0.9-31.8, P <0.06)]. Ever worked in farming [OR 2.8 (95% CI: 1.1-7.2, P <0.03)] and history of cirrhosis [OR 3.6 (95% CI: 1.6-8.1, P <0.01)] or blood transfusion [OR 4.2 (95% CI: 0.99-17.8, P <0.05)] were also associated with increased HCC risk. This study in a predominantly rural area in Egypt supports previous reports from other parts of Egypt that HCV infection is the primary HCC risk factor in Egypt. Further understanding of the relationship between infection and other risk factors in the development of HCC could lead to targeted interventions for at-risk individuals. KEYWORDS: hepatocellular carcinoma; hepatitis; rural; risk factors; Egypt.

Invasive Group C Streptococcus infection associated with rhabdomyolysis and disseminated intravascular coagulation in a previously healthy adult.

Infections with Group C Streptococci can lead to severe disease, particularly in individuals with underlying illnesses such as cardiovascular disease, malignancy or immunosuppression. We report the first case of rhabdomyolysis and disseminated intravascular coagulation secondary to Group C Streptococcus in a previous healthy male. A toxic shock-like syndrome associated with Group C and Group G Streptococci has been reported. However, unlike with Group A Streptococci, production of endotoxins by these organisms is less well defined. We tested the patient's isolate for its ability to produce superantigenic toxins and to induce a mitogenic response. Although it is not known whether Group C Streptococci require special growth conditions for the production of superantigens, we could not demonstrate either the production of exotoxins or the induction of a mitogenic response.

Clinical and laboratory diagnosis of influenza virus infections.

Influenza epidemics account for more than 20,000 deaths in the United States each year, as well as substantial morbidity, medical costs, and time away from work and school. Since the 1950s, the principal weapon against these seasonal epidemics has been killed virus vaccine formulations. Despite massive efforts to immunize at-risk individuals against influenza, not everyone receives the vaccine. In addition, use of some drugs, such as amantadine and rimantadine, can lead to the development of drug resistant viruses in infected individuals and to transmission of these viruses to susceptible individuals. The many factors that contribute to the high annual incidence of influenza virus infections mandate prompt clinical recognition and appropriate patient management. Rapid diagnostic tests have been developed that may make it possible to avoid the use of antibacterial drugs, quickly decide whether isolation of infected patients is needed, and discharge hospitalized patients sooner.

MHC class II-independent, Vbeta-specific activation of T cells by superantigen mutants fused to anti-tumor Fab fragments: implications for use in treatment of human colon carcinoma.

Genetically engineered fusion proteins of the super-antigen staphylococcal enterotoxin A (SEA) and tumor-reactive monoclonal antibodies, C215Fab-SEA and C242Fab-SEA, have been generated and shown to be effective in mediating superantigen-antibody directed cellular cytotoxicity against human carcinoma cells expressing the CA215 or CA242 antigens in an MHC class II-independent manner. In an attempt to reduce the in vivo toxicity of superantigen administration, alanine substitution mutations in SEA at residues F47 and D227 that affect SEA binding to class II molecules have been created and genetically linked to C215Fab or C242Fab. The purpose of this study was to determine whether these Fab-SEA mutant fusion proteins, that have low MHC class II binding affinities, were still able to stimulate human T cells in a Vbeta-specific manner in the presence or absence of MHC class II molecules. The SEA wt- and SEA-D227A-based fusion proteins shared the ability to activate V beta5. 2-, Vbeta6-, Vbeta7-, Vbeta9- and Vbeta18-bearing T cells, whereas Fab-SEA-F47A protein activated only Vbeta6- and Vbeta7-bearing T cells. The fusion of Fab fragments onto SEA wt, SEA-F47A or SEA-D227A had no effect on the Vbeta specificity of these superantigens. Fab fusion proteins containing either SEA wt or SEA mutants were presented, in the absence of class II molecules, by CHO cells transfected with CA215 and CD80 and all induced the expansion of only Vbeta6-, Vbeta7- and Vbeta 18-bearing T cells. Fab-SEA mutant fusion proteins may provide attenuated therapeutic agents that, while still able to specifically target high affinity T cells for MHC class II-independent local tumor killing, will not induce excessive systemic toxicity.

Superantigen-based immunotherapy: a phase I trial of PNU-214565, a monoclonal antibody-staphylococcal enterotoxin A recombinant fusion protein, in advanced pancreatic and colorectal cancer.

PURPOSE: To establish the maximum-tolerated dose (MTD) and define the toxicities of a single-dose infusion of PNU-214565, a recombinant Escherichia coli-derived fusion protein of Staphylococcal enterotoxin A (SEA) and the Fab-fragment of the C242 monoclonal antibody in patients with advanced colorectal and pancreatic carcinomas. To investigate the capability of PNU-214565 to induce a superantigen (SAg) response resulting in cytokine production and tumor regression. PATIENTS AND METHODS: Twenty-one patients (age range, 39 to 76 years; median, 64; 12 men, nine women; 18 colorectal, three pancreatic cancers) were treated with a single 3-hour infusion of PNU-214565, with doses ranging from 0.01 to 1.5 ng/kg. All patients had prior chemotherapy and a good performance status Eastern Cooperative Oncology Group [ECOG] performance status [PS] = 0 [n = 10]; PS = 1 [n = 11]), 10 had prior radiation, and 18 had prior surgery. RESULTS: Fever and hypotension were the most common toxicities. Fever of any grade occurred in 16 of 21 patients (76%): four of 21 (19%) with grade 2 and two of 21 (9.5%) with grade 3. Hypotension of any grade occurred in 13 of 21 (62%): four of 21 with grade 2 and one of 21 (5%) with grade 3. Interleukin-2 (IL-2) and tumor necrosis factor alpha (TNF alpha) induction correlated with toxicity. In the two patients with grade 3 fever, peak IL-2 and TNF alpha levels were 2.9 IU/mL and 165 pg/mL, and 8.3 IU/mL and 245 pg/mL, respectively. Transient, > or = 50% decreases in circulating monocytes were observed in 17 of 21 patients as early as 0.5 hours (median time, 2 hours) from the start of infusion. Decreases (mean 33%) in circulating lymphocytes were observed in seven of 21 patients. All three patients with grade 3 toxicity were treated at the 0.5-ng/kg dose. The significance of baseline anti-SEA, human antimouse antibody (HAMA), CA242-soluble antigen levels, and T-cell receptor variable beta region (TCR V beta) subsets and histocompatibility leukocyte antigen-DR (HLA-DR) genotypes was assessed as possible predictors of toxicity. All toxicities were transient and easily managed. No grade 3 toxicity occurred at the higher dose levels. CONCLUSION: PNU-214565, a SAg-based tumor targeted therapy, is safe when given as a single 3-hour infusion at doses up to 1.5 ng/kg. The MTD for a single dose was not determined. The safety of a repeated dose schedule is currently under investigation, beginning with doses determined to be safe in this trial.

Effect of fat emulsion and supersaturation on calcium phosphate solubility in parenteral nutrient admixtures.

The calcium concentration in 0.2 micrometer porosity membrane filtrates of parenteral nutrient admixtures (PNAs) was measured by atomic absorption spectroscopy. The PNAs contained 22% dextose, 2.7% crystalline amino acids; 0% to 3.2% safflower and soybean oils from intravenous fat emulsion, 19-24 mEq/L calcium gluconate, and 22-28 mmol/L sodium phosphates. The calcium and phosphates concentrations caused visible precipitation of dibasic calcium phosphate, CaHPO4, in all fat-free samples. The results were the following: (1) Fat-free PNAs containing FreAmine III 8.5% with electrolytes resulted in supersaturation of CaHPO4 from which CaHPO4 continued to precipitate for 14 days after three successive 0.2 micrometers porosity filtrations; (2)egg-yolk phospholipids caused a statistically insignificant 1% to 11% increase in calcium solubility; (3)at the same pH, the calcium solubility was 10% higher in 2.7% amino acids and 22% dextrose than in 22% dextrose alone. The growth kinetics of CaHPO4 crystals in PNAs do not appear to be predictable. Both transient and permanent precipitation of CaHPO4 can result when the product of the Ca+2 and HPO4-2 ion concentrations exceeds the solubility product (Ksp) of CaHPO4 either before or after the compounding of a PNA is completed. Both transient precipitation at subsaturated and permanent precipitation at saturated and supersaturated CaHPO4 concentrations can be clinically dangerous. All PNAs containing calcium and inorganic phophates should be infused through a sterile filter with appropriate mean microporosity, eg, usually 1.2 micrometer for fat emulsion-containing and 0.2 or 0.45 micrometer for fat-free formulations.

Mutations in the MHC class II binding domains of staphylococcal enterotoxin A differentially affect T cell receptor Vbeta specificity.

C-terminal residues of staphylococcal enterotoxin A (SEA), including H187, D225, and D227, are involved in moderate affinity binding to MHC class II beta-chain, whereas N-terminal residues, including F47, are involved in low affinity binding to MHC class II alpha-chain. The effect of alanine substitutions at residues D227 or F47 on induction of T cell proliferation and the expansion of specific TCR Vbeta families was determined. SEA wild type specifically activated T cells expressing Vbeta1, Vbeta5.2, Vbeta6, Vbeta7, Vbeta9, Vbeta18, and Vbeta22. Although SEA-D227A exhibited substantially reduced mitogenicity compared with SEA wild type, it expanded the same Vbeta-bearing T cells, except those expressing Vbeta1. By contrast, SEA-F47A, which was slightly less mitogenic than SEA wild type, induced expansion only of T cells expressing Vbeta6, Vbeta7, and to a lesser extent Vbeta22. Therefore, specific mutations affecting either MHC class II alpha or beta binding sites differentially affect the Vbeta specificity of this superantigen. The lack of expansion in four of seven Vbeta families by SEA-F47A suggests that the class II alpha binding site may position SEA on the MHC class II molecules in an appropriate conformation for interaction with certain Vbeta elements.

Plasma from patients with severe invasive group A streptococcal infections treated with normal polyspecific IgG inhibits streptococcal superantigen-induced T cell proliferation and cytokine production.

Previous studies have suggested a central role for superantigen-induced immune responses in the pathogenesis of streptococcal toxic shock syndrome. The production of streptococcal superantigens by clinical group A streptococcal (GAS) isolates was studied, and the ability of plasma collected from patients with severe invasive GAS infections to neutralize the proliferative- and cytokine-inducing activities of these superantigens was investigated. Overnight culture supernatants from all GAS isolates obtained from patients with invasive disease were found to contain superantigenic activity, as evident from their ability to drive potent T cell proliferation, induce high production of cytokines, and stimulate T cells in a V beta-specific manner. Twelve patients with severe invasive GAS infections, including 11 streptococcal toxic shock syndrome cases and one necrotizing fasciitis without shock, were treated with i.v. infusions of normal polyspecific Ig (IVIG). Plasma samples collected from each patient before and after IVIG administration were analyzed for their ability to neutralize the activity of streptococcal superantigens produced by the GAS isolate that caused their disease. In all IVIG-treated patients, the capacity to neutralize the superantigenic activity, produced by their respective GAS isolate or by purified streptococcal pyrogenic exotoxins, increased in plasma following IVIG administration. Of particular clinical relevance, post-IVIG plasma from each patient completely blocked cytokine production elicited by their respective GAS culture supernatants or by purified streptococcal pyrogenic exotoxins. This study shows that IVIG treatment confers in vivo inhibitory activity against a large array of streptococcal superantigens and suggests that IVIG may be useful in the treatment of severe invasive streptococcal infections.

Prospects for controlled-delivery systems.

Americans seem to view medical progress as a citizen's entitlement. They expect, and researchers expect to seek, cures for acquired immunodeficiency syndrome (AIDS), Alzheimer's disease, cancer, and other deadly or incapacitating diseases. Both the public and researchers also seem undaunted by the cost. CDS technologies and biotechnology drugs are making this expectation possible. Still, CDSs may not dispel public resentment over the high cost--and profit--of discovering otherwise welcomed new healing molecules. As noted by 1988 Nobel laureate in medicine, Sir James Black: "I think both the press and industry have failed to communicate to the public that behind every little pill is a vast amount of high technology...." With increasing use of and satisfaction from CDSs, more of these mechanisms, covering a broadening spectrum of uses, will be marketed. Because these products are taken less often, patient compliance is expected to increase. As more CDSs are introduced, dispensing frequency will decline and the complexity of prescription drugs will increase. Pharmacists can take advantage of this trend by expanding their activities in the management their patients' medication use.

Enhanced splenic bacterial clearance and neutrophilia in anti-NK1.1-treated mice infected with Pseudomonas aeruginosa.

The purpose of the present study was to further delineate the role of natural killer (NK) cells in the early stages of resistance to infection by Pseudomonas aeruginosa, strain PAO1. Intravenous injection of the monoclonal antibody alpha-NK1.1 resulted in an 82% reduction in NK cell activity of normal mice, as measured by a standard 4-hour 51Cr release assay. Splenic bacterial clearance was examined in mice treated with this antibody 12 h prior to infection with a sublethal dose (10(6)) of PAO1. At 2, 4, and 6 h postinfection there was significant enhancement (up to 10-fold) of clearance in mice treated with alpha-NK1.1 when compared to untreated infected control animals. Interestingly, the enhanced clearance of PAO1 in the spleens of NK-depleted mice was found to be coupled to a significant increase in neutrophils. Normal murine spleens were found to contain 1-2% neutrophils, which increased to 6-7% following sublethal infection. However, in mice treated with alpha-NK1.1 and infected, splenic neutrophils increased up to 15% during the early stages of infection. The data presented here suggests that NK cells do not have direct bactericidal activity against Pseudomonas, but may regulate other effector cells, such as neutrophils-an indirect role for natural killer cells, probably mediated in vivo by their production and secretion of cytokines.