Immune-tolerant elastin-like polypeptides (iTEPs) and their application as CTL vaccine carriers.

BACKGROUND: Cytotoxic T lymphocyte (CTL) vaccine carriers are known to enhance the efficacy of vaccines, but a search for more effective carriers is warranted. Elastin-like polypeptides (ELPs) have been examined for many medical applications but not as CTL vaccine carriers. PURPOSE: We aimed to create immune tolerant ELPs using a new polypeptide engineering practice and create CTL vaccine carriers using the ELPs. RESULTS: Four sets of novel ELPs, termed immune-tolerant elastin-like polypeptide (iTEP) were generated according to the principles dictating humoral immunogenicity of polypeptides and phase transition property of ELPs. The iTEPs were non-immunogenic in mice. Their phase transition feature was confirmed through a turbidity assay. An iTEP nanoparticle (NP) was assembled from an amphiphilic iTEP copolymer plus a CTL peptide vaccine, SIINFEKL. The NP facilitated the presentation of the vaccine by dendritic cells (DCs) and enhanced vaccine-induced CTL responses. DISCUSSION: A new ELP design and development practice was established. The non-canonical motif and the immune tolerant nature of the iTEPs broaden our insights about ELPs. ELPs, for the first time, were successfully used as carriers for CTL vaccines. CONCLUSION: It is feasible to concurrently engineer both immune-tolerant and functional peptide materials. ELPs are a promising type of CTL vaccine carriers.

Triggers for foot and mouth disease vaccination in the United States.

In the United States, the national policy for foot and mouth disease (FMD) vaccination lacks clarity. To better understand what potential Incident Commanders see as important 'triggers' or factors to consider for implementing vaccination as a control strategy, the authors presented seven such individuals with an FMD outbreak scenario that started in north-western Illinois and spread across state lines by the end of the fifth week. The scenario had four infected premises at the end of week one, 13 at the end of week two, and 60 (including both infected and previously depopulated premises) by the end of week five. Two individuals favoured vaccination the first week of the outbreak scenario, one did not want to vaccinate during the scenario, and the remainder wanted vaccination at some time during the scenario. Respondents ranked nine specific factors to take into consideration when deciding whether or not to vaccinate. Of these, the capability to manage the outbreak by stamping out ranked first. Many of the issues raised in this report are applicable to other countries that are currently FMD-free without vaccination.

[Issues of France's "Leonetti Act": Involvement of amyotrophic lateral sclerosis patients in prior discussions concerning respiratory support and end-of-life care]. / Les enjeux de la loi Leonetti: participation des patients atteints de sclérose latérale amyotrophique à une discussion anticipée sur la réanimation respiratoire et les soins de fin de vie.

In accordance with the principle of personal autonomy, expert consensus statements on amyotrophic lateral sclerosis (ALS) recommend early engagement with terminal-phase patients on the type of symptomatic treatment to be administered in the event of respiratory failure, since decompensation progresses too rapidly to allow time for a discussion. The French Parliamentary Act on Patients' Rights and End-of-Life Care (dated 22 April 2005) grants individuals the right to refuse unreasonable treatment and obliges physicians to take account of any prior instructions given by a person before he/she became incapable of communicating. The provision of prior instructions is a very reassuring situation for the physician: the autonomous patient indicates his or her choice of end-of-life care. However, there are two pitfalls which must be avoided: (i) holding a discussion for the sole purpose of obtaining prior instructions and (ii) not acknowledging the patient's vulnerability. The present study dealt with 35 ALS patients for whom the question of either intensive care or palliative end-of-life care remained open. Even though the great majority of these individuals were keen to know their exact state of health, 48% refused to consider this circumstance and only 20% expressed prior instructions. These results prompted us to question the ethical dimension of the concept of autonomy beyond its founding formulation: can one envisage an incapacity to confront oneself with the existential question of possible death? In 80% of cases, the physician will have to take a care decision in the absence of any prior instructions from the patient. This amounts to more than respecting a person's autonomy and involves exercising medical responsibility.

Developing a home care system by design.

Developing and implementing a national approach to home care has been an ongoing and sometimes controversial point of debate between the provinces and the federal government for a few years. We agree that Canada is ready for such a model, but the policy instruments imbedded in the model must be carefully considered in our commentary we expand on several points made by the lead paper, but focus specifically on the proposed model with respect to the suggested policy instrument recommended for financing the model and some of the key issues surrounding the delivery of home care. It is imperative from our perspective that the current political environment be fully understood to appreciate the context in which the model would be introduced. We argue t ha t understanding the complexities of home care is one thing, resolution of the issues in the model proposed is another. Although the federal government has agreed that there will be more dollars infused through the Canada Health and Social Transfer, the suggested policy instrument recommended for financing the model does not assure that home care programs will receive the funding that is required when other important and competing interests are considered (e.g., cancer treatment and waiting lists). We are at a point where there is incredible potential to reconfigure the health system such that home and community-based care can play a much greater role, but how do we fully realize that potential? The first step is to take the opportunity afforded by the huge surplus of the federal government and to invest heavily in developing home care -to create a system by design. That means thinking about funding directed to home care as an investment, and not as a cost. More funding, however, has limited utility without a sense of where the funding should be targeted, and for what purpose. We agree in principle that a national approach is required to advance and support home care to meet the needs of the future with the correct policy instruments. What happens in the next couple of years will shape that long-term model of home care. Whether that be by default or design is contingent on the willingness and commitment of the politicians and policymakers, and the degree to which the Canadian public have a voice that will be heard.

Acid reduction in peptic ulcer disease. Choosing therapy according to drug interactions, individual response, and cost.

Reduction of gastric acid secretion is important in healing ulcers and maintaining remission. As pharmacologic agents have improved, first-line therapy has moved from antacids and anticholinergics to histamine2 (H2) receptor antagonists and the proton pump inhibitor omeprazole (Prilosec). If H2 blocker therapy is used, choosing one of the newer agents may be prudent to avoid potential drug interaction. Omeprazole is an effective acid reducer, particularly at the high dose (40 mg/day). However, cost and uncertainty regarding long-term safety prevent some physicians from abandoning the effective H2 blockers in favor of omeprazole. Cimetidine is now available in generic form, which will probably influence the choice of acid-reduction therapy.

Randomized controlled trial of recombinant alpha-2a-interferon for chronic hepatitis C. Comparison of alanine aminotransferase normalization versus loss of HCV RNA and anti-HCV IgM.

We enrolled 32 patients with chronic hepatitis C into a randomized, controlled trial to evaluate the efficacy of recombinant alpha-2a-interferon treatment. Sixteen patients were randomized to receive 1.5 million units of recombinant alpha-2a-interferon subcutaneously, thrice weekly, for six months while the remaining 16 patients were randomized to a control group that received no treatment. The mean serum alanine aminotransferase (ALT) level during the six-month study period, expressed as a percentage of the prestudy baseline value, was 82% for the control group compared to 56% for the treatment group (P = 0.014). One fourth of the treatment group normalized their serum ALT level compared to only 6% of the controls (P = 0.05). During posttherapy follow-up, 86% of responders clinically relapsed. Loss of anti-HCV IgM and HCV RNA occurred exclusively in interferon-treated responders. Anti-interferon antibodies developed in 32% of all treated patients. Forty percent of nonresponders developed anti-interferon antibodies compared to only 14% of responders (P = NS). We conclude that recombinant alpha-2a-interferon is clinically effective in patients with chronic hepatitis C. However, most responders in this trial of low-dose interferon relapsed upon cessation of treatment.

Accuracy of assessment of the extent of examination by experienced colonoscopists.

One hundred colonoscopies were done. The colonoscopist noted whether the cecum had been intubated as well as the markers used to make this determination. With the colonoscope in position at maximum penetration, a radiologist independently determined its position using fluoroscopy, with a contrast agent delivered through the colonoscope. The cecum was entered in 86 of 100 cases. The tip of the colonoscope was at the level of the ileocecal valve in nine additional cases; the colonoscopist judged that the cecum was well seen in five of these nine. In one case, the colonoscopist overestimated the extent of the examination when transillumination in the right lower quadrant was the only confirming marker. When the more reliable markers (ileocecal valve, appendiceal orifice, converging indentations of the taenia coli in the cecal pole) were seen, no errors were made. Experienced colonoscopists are accurate in assessing the extent of colonoscopy and fluoroscopic confirmation is not routinely needed. When reliable markers are not seen during the examination, a barium enema, preferably with air contrast, should be done.

Barium enema versus colonoscopy for patients with polyps found during flexible sigmoidoscopy.

This prospective study compares the accuracy of barium enema examination performed by experienced radiologists to colonoscopy performed by experienced gastroenterologists blinded to the radiographic findings to detect proximal, synchronous lesions in patients with polyps detected during fiberoptic sigmoidoscopy. Three thousand six patients were examined, of whom 147 (5%) had polyps larger than 0.5 cm in diameter. Of 114 patients who completed the protocol, 46 patients (40%) had synchronous, proximal colonic lesions. There were no radiographic false positives, but the single-contrast barium enema missed polyps in 13 while detecting polyps in 2 patients (sensitivity = 13%). The double-contrast barium enema missed proximal polyps in 23 patients while detecting them in 8 (sensitivity = 26%). We conclude that patients with neoplastic polyps found during fiberoptic sigmoidoscopy should have colonoscopy without barium enema. If the entire colon cannot be examined at colonoscopy, we advise double-contrast barium enema.

Long-term versus short-term treatment with recombinant interferon alfa-2a in patients with chronic hepatitis B: a prospective, randomized treatment trial.

We conducted a prospective, randomized trial to study the efficacy and tolerance of long-term versus short-term treatment with recombinant interferon alfa-2a in patients with chronic hepatitis B. Ten patients were randomly assigned to a 6-month interferon regimen, and 10 patients were assigned to a 3-week interferon trial. Eleven patients (five assigned to long-term treatment and six to short-term treatment) did not complete interferon therapy: eight had either severe thrombocytopenia or neutropenia; one had pronounced fatigue in relationship to administration of interferon; one had spontaneous bacterial peritonitis and sepsis and died; and one had a massive fatal variceal hemorrhage during interferon therapy. Most of the serious hematologic complications occurred in patients with cirrhosis and hypersplenism. In one patient, seroconversion to hepatitis B virus DNA negativity occurred before the onset of treatment. Four of the five patients able to complete the 6-month interferon regimen and only one of four patients able to complete the 3-week trial had seroconversion to hepatitis B virus DNA negativity. Thus, we conclude that the therapeutic response was better among patients who were able to complete a 6-month interferon trial. In patients with cirrhosis and hypersplenism, development of either severe thrombocytopenia or leukopenia associated with interferon therapy precluded completion of treatment.

The significance of diminutive colonic polyps found at flexible sigmoidoscopy.

In order to determine the importance of identification and follow-up of diminutive colonic polyps (DCPs) (i.e., those less than or equal to 5 mm in diameter), we studied 3006 patients undergoing flexible sigmoidoscopy. DCPs were found in 315 patients (10.5%). Biopsy of these lesions showed them to be nonneoplastic in 187 patients (59.4%) and neoplastic in 128 (40.6%). Overall, 35% of all DCPs found were neoplastic. Gross appearance of the lesions was found to be an unreliable means of predicting their histologic makeup. Of the 128 patients with neoplastic DCPs, 73 underwent further examination with barium enema and colonoscopy. Synchronous lesions were found in 57.5%. In 10 patients, synchronous lesions were of significance, including carcinomas, adenomas greater than or equal to 8 mm in diameter, or severely dysplastic adenomas. We conclude that all DCPs discovered at sigmoidoscopy should be biopsied and in patients in whom DCPs are found to be neoplastic, colonoscopy should be undertaken to search for proximal synchronous lesions.

A detailed study of gerJ mutants of Bacillus subtilis.

A total of nine gerJ mutants have now been isolated in Bacillus subtilis. All are defective in their spore germination properties, being blocked at an intermediate (phase grey) stage. The dormant spores are sensitive to heating at 90 degrees C and two of the mutants (generated by transposon insertion) produce spores sensitive at 80 degrees C. The spores of these two more extreme mutants had a visibly defective cortex when studied by electron microscopy, as did some of the other mutants. During sporulation, the acquisition of spore resistance properties and the appearance of the sporulation-specific penicillin-binding protein PBP5* were delayed. A strain probably carrying a lacZ fusion to the gerJ promoter demonstrated increased expression between t2 and t4. We propose that the gerJ locus is involved in the control of one or more sporulation-specific genes.

Central, as well as peripheral naloxone administration suppresses feeding in food-deprived Sprague-Dawley and genetically obese (Zucker) rats.

Food intake over 90 min post-injection was studied in groups of food deprived (20 hr) female Sprague-Dawley (S.D.) rats, fatty Zucker (fa/fa) rats and their heterozygous lean litter mates (Fa/fa) of various ages, that bar-pressed for food pellets on a FR-1 schedule following a subcutaneous (SC) or an intracerebroventricular (IVT) injection of sterile saline or naloxone HCl. Subcutaneous injections of naloxone HCl (10 mg/kg) reduced feeding in all three groups of rats compared to SC saline; in addition, a greater percentage reduction in food intake over the whole 90 min test period occurred in the fa/fa rats given SC naloxone compared to the Fa/fa group. Intracerebroventricular naloxone (50 micrograms) decreased feeding over the initial 30 min period in the S.D. and Fa/fa rats but a 100 micrograms IVT dose was needed to reduce feeding in the fa/fa group. The results demonstrate that central naloxone administration can suppress feeding in both non-obese and obese strains of rats as it is known to do when given peripherally. These findings add yet further evidence to the premise that endogenous opioid peptides may play an intricate and important physiological role in the regulation of feeding behavior.

Lymphocytotoxic and microbial antibodies in Crohn's disease and matched controls.

Patients with Crohn's disease and age, sex and seasonally matched healthy controls were studied for cold lymphocytotoxic and a variety of microbial antibodies. Lymphocytotoxic antibody titers were increased significantly in the Crohn's patients compared to controls, but did not correlate with any of the microbial titers. Antibodies to a Pseudomonas-like bacterium and Bacteroides vulgatus were also increased in the patients, but titers to Chlamydia trachomatis, rotavirus and Norwalk virus were not elevated above control values. Analysis of microbial antibody within the patient and control groups revealed a significant (P = .001) correlation between antibodies to the Pseudomonas-like bacterium and Bacteroides vulgatus. The elevated titers to the Pseudomonas-like organisms and B. vulgatus are of potential importance, but their significance is not known at this time. There is no evidence of an increased incidence of infection with C. trachomatis, rotavirus or Norwalk virus in Crohn's disease.

Cell wall-defective variants of pseudomonas-like (group Va) bacteria in Crohn's disease.

Several animal transmission studies have indicated that Crohn's disease may be caused by a filterable agent. Filtrates of homogenized tissues were prepared from 8 patients with Crohn's disease, 9 patients with chronic ulcerative colitis, and 20 control patients without inflammatory bowel disease. Conventional bacteriological cultures and hypertonic cultures for cell wall-defective bacterial variants were performed on the filtrates. Bacterial revertants (parent forms) of cell wall-defective variants were obtained from filtrates of various tissues including mesenteric lymph nodes of all patients with Crohn's disease. In no instance were revertants cultured from tissue filtrates of the other patients. The 11 revertants isolated from the 8 patients were identified as Pseudomonas-like bacteria, most closely identifiable with group Va.

Bacterial variants: etiologic agent in Crohn's disease?

Bacterial variants of Pseudomonas maltophilia and Pseudomonas-like bacteria were recovered from tissues removed during the surgical treatment of three successive patients with Crohn's disease and from one patient with clinical and pathological features of both Crohn's disease and chronic ulcerative colitis. Bacterial variants were not cultured from colonic specimens of one patient with classical features of chronic ulcerative colitis and two patients with adenocarcinoma of the colon. The findings suggest that a relationship exists between variant bacteria and the pathogenesis of Crohn's disease.

Mycobacteriophage in Crohn's disease.

Numerous similarities between Crohn's disease and sarcoidosis are being reported. Because of previous findings of culturable mycobacteriophage in the serum of many patients with sarcoidosis, mycobacteriophages were sought in serum of patients with Crohn's disease. No difference was found in the frequency of positive cultures between patients with Crohn's disease and normal control subjects.