SUMMARY:Recombinant human type I collagen, identical in structure and functionality to human type I collagen, was successfully expressed and extracted from genetically modified tobacco plants. Contrarily to tissue extracted protein, rhCollagen is not immunogenic and not allergenic and has an intact triple helix structure showing superior biological functionality. A photocurable rhCollagen was developed by chemically modifying the protein to allow cross-linking under illumination at various wavelengths, maintaining the protein structural and biological functions. The use of the photocurable rhCollagen in aesthetic medicine, especially as a dermal filler and as a bioink for 3D-printed breast implant is discussed in this article.

Recombinant human collagen type I hydrogels as superior cell carriers for corneal epithelial stem cells

Bone morphogenetic protein (BMP)/carriers approved for orthopedic procedures achieve efficacy superior or equivalent to autograft bone. However, required supraphysiological BMP concentrations have been associated with potential local and systemic adverse events. Suboptimal BMP/receptor binding and rapid BMP release from approved carriers may contribute to these outcomes. To address these issues and improve efficacy, we engineered chimeras with increased receptor binding by substituting BMP-6 and activin A receptor binding domains into BMP-2 and optimized a carrier for chimera retention and tissue ingrowth. BV-265, a BMP-2/BMP-6/activin A chimera, demonstrated increased binding affinity to BMP receptors, including activin-like kinase-2 (ALK2) critical for bone formation in people. BV-265 increased BMP intracellular signaling, osteogenic activity, and expression of bone-related genes in murine and human cells to a greater extent than BMP-2 and was not inhibited by BMP antagonist noggin or gremlin. BV-265 induced larger ectopic bone nodules in rats compared to BMP-2 and was superior to BMP-2, BMP-2/6, and other chimeras in nonhuman primate bone repair models. A composite matrix (CM) containing calcium-deficient hydroxyapatite granules suspended in a macroporous, fenestrated, polymer mesh-reinforced recombinant human type I collagen matrix demonstrated improved BV-265 retention, minimal inflammation, and enhanced handling. BV-265/CM was efficacious in nonhuman primate bone repair models at concentrations ranging from 1/10 to 1/30 of the BMP-2/absorbable collagen sponge (ACS) concentration approved for clinical use. Initial toxicology studies were negative. These results support evaluations of BV-265/CM as an alternative to BMP-2/ACS in clinical trials for orthopedic conditions requiring augmented healing.

Objectives. We examined the association between Helicobacter pylori infection and the incidence of diarrheal diseases.Methods. In a nested case-control study participants were sampled from cohorts of male Israeli soldiers aged 18-21 years, serving in field units and followed up for diarrheal diseases. Case patients (n = 177) were subjects who visited the base clinic because diarrhea and were positive for Shigella sonnei (n = 66), enterotoxigenic Escherichia coli (ETEC) (n = 31) or negative for bacterial pathogens (n = 80; diarrhea of unknown etiology). Controls (n = 418) were subjects who did not suffer from a diarrheal disease during the follow-up. They were matched to case patients by training unit and period. Serum samples were obtained from participants at the beginning of their field training and were tested for anti-H. pylori immunoglobulin (Ig) G and preexisting Shigella sonnei lipopolysaccharide IgG and IgA antibodies using enzyme-linked immunosorbent assay.Results. The proportion of H. pylori-infected subjects was significantly lower among case patients with infection of unknown etiology (36.3%) than among controls (56.0%) (adjusted odds ratio [OR], 0.43; 95% confidence interval [CI], .24-.77; P = .005). The proportion of H. pylori-infected subjects among case patients with S. sonnei shigellosis was also significantly lower than in the control group: 36.3% versus 56.0%. The association persisted after adjusting for sociodemographic variables and preexisting S. sonnei serum IgA antibodies (adjusted OR, 0.37; 95% CI, .14-.95; P = .03) and IgG antibodies (adjusted OR, 0.38; 95% CI, .14-.99; P = .04). The direction of the association between H. pylori infection and ETEC diarrhea was similar, albeit not statistically significant.Conclusions. Our findings suggest an active role of H. pylori in protection against diarrheal diseases.

BACKGROUNDSuccessful smallpox vaccination is traditionally defined by clinical response ("take"). Nevertheless, only 60% of subjects in the 2002 Israeli smallpox revaccination campaign developed clinical take. More sensitive immunological markers are needed to document successful revaccination. We compared the level of vaccinia-specific immune markers among subjects who did or did not develop clinical take following revaccination.METHODSForty subjects who participated in 2002 smallpox revaccination campaign and developed clinical take were individually matched for age, sex, and smallpox vaccinations with subjects who did not develop clinical take ("no-take"). Vaccinia immunity markers were examined prior to and 14 days and 2 years after revaccination.RESULTSHigher levels of total immunoglobulin (Ig) G, IgG1, and neutralizing antibodies (highest dilution of serum that inhibited the cytopathic effect by at least 50% [PRNT50]) were observed in the no-take group before vaccination (166 vs 94.3 ELISAU/mL [P<.05], 53.2 vs 34.5 ELISAU/mL [ P<.05], and 30% vs 19.7% [P<.05], respectively). The mean time since last smallpox vaccination was longer in the take group than in the no-take group. Total IgG, IgG subclasses, avidity index, and PRNT50 levels were higher among "take" than "no-take" volunteers 14 days after revaccination. The no-take group was not inferior to the take group in all vaccinia immune marker levels measured 24 months after vaccination. Moreover, mean interferon-γ secretion and the percentage of serum samples with PRNT50 levels ≥1:32 were significantly higher in the No-take group than in the take group (677.5 vs 282.7 pg/mL [P < .05] and 95% vs 80% [P<.05], respectively).CONCLUSIONSThe overwhelming majority of subjects in the no-take group were successfully revaccinated against smallpox. Under circumstances of emergent smallpox mass immunization, there is no need for revaccination success assessment among individuals who have received multiple previous smallpox vaccinations.

West Nile virus (WNV) is a mosquito-borne disease found most commonly in Africa, west Asia, and the Middle East, where up to 40% of the human population possesses antibodies. It is an emerging disease in the United States, since 1999 and has spread all over the US and Canada. The virus is maintained in nature in a mosquito-bird-mosquito cycle (primarily Culex), with human horses and other animals serving as incidental hosts. WN infection in humans is usually asymptomatic or involves flu like illness but can develop to severe meningo-encephlitis, with symptoms including cognitive dysfunctions, muscle weakness, paralysis and even death. Elderly and depressed immunity factors are at greatest risk of developing severe neurological disease. Studies in animal models have enhanced significantly the understanding of the viral and host factors that determine the pathogenesis and outcome of WNV disease. Currently, vaccines are available for animal use but there is no effective antiviral therapy or human vaccine for WNV infection. Passive administration of antibodies produced from selected donors has shown promising results in animal models.

BACKGROUND:Mass vaccination is the principal preventive measure against a smallpox outbreak after an act of bioterrorism. Vaccination of subjects who received immunosuppressive therapies is problematic because of smallpox vaccine reactogenicity. Moreover, long-term immunity to vaccinia might be affected.OBJECTIVE:The objective of the study was to examine the effect of cytotoxic chemotherapy on long-term immunity to vaccinia.METHODS:In a case-control study, 67 patients with breast cancer who received cytotoxic chemotherapy and who were disease free for at least 1 year were matched with healthy controls according to age, sex, and the number of smallpox vaccinations received. Markers of immunity to smallpox were examined. Forty-one patients with breast cancer who did not receive chemotherapy were used to assess the affect of cancer and radiotherapy on immunity to smallpox.RESULTS:Patients with breast cancer who received chemotherapy had lower levels of vaccinia total immunoglobulin G and immunoglobulin G1 (expressed as enzyme-linked immunosorbent assay units per milliliter), neutralizing antibodies, vaccinia:memory B cell ratio (expressed as a percentage), and interferon-gamma level (expressed as picograms per milliliter), compared with healthy control individuals.CONCLUSIONS:Immunity to smallpox is reduced after receipt of chemotherapy for breast cancer. This finding should be considered when planning smallpox vaccination campaigns. The effect of immunosuppressive treatments on persistence of immunity should be tested with respect to additional vaccines or natural infections.

The therapeutic potential of human vaccinia immunoglobulin (VIG) in orthopoxvirus infection was examined using two mouse models for human poxvirus, based on Ectromelia virus and Vaccinia Western Reserve (WR) respiratory infections. Despite the relatively fast clearance of human VIG from mice circulation, a single VIG injection protected immune-competent mice against both infections. Full protection against lethal Ectromelia virus infection was achieved by VIG injection up to one day post-exposure, and even injection of VIG two or three days post-infection conferred solid protection (60–80%). Nevertheless, VIG failed to protect VACV-WR challenged immune-deficient mice, even though repeated injections prolonged SCID mice survival. These results suggest the involvement of host immunity in protection. VIG provides the initial protective time-window allowing induction of the adaptive response required to achieve complete protection. Additionally, VIG can be administered in conjunction with active Vaccinia-Lister vaccination. Vaccine efficiency is not impaired, providing a non-prohibitive VIG dose is used. Thus, VIG can be used as a prophylactic measure against post-vaccinal complications but could also serve for post-exposure treatment against smallpox.

BACKGROUND:Ecthyma is an invasive, ulcerated skin infection. Four ecthyma outbreaks occurred in different infantry units in the Israeli Defense Force from October 2004 through February 2005. Morbidity attack rates in the first 3 outbreaks were 89% (49 of 55 soldiers), 73% (32 of 44), and 82% (37 of 45). In the fourth outbreak, in which early intervention (antimicrobial treatment and improvement of hygiene) was applied, the attack rate was 25% (10 of 40 soldiers). In the first outbreak cluster, 4 soldiers experienced poststreptococcal glomerulonephritis, and 5 cases of systemic sequelae were recorded (1 case of severe septic shock, 3 cases of pneumonia, and 1 case of septic olecranon bursitis).METHODS:Streptococcus pyogenes and Staphylococcus aureus were isolated from ecthyma sores, oropharynx, and anterior nares of affected and unaffected soldiers involved in all 4 outbreaks.RESULTS:Although the S. aureus isolates had different genomic profiles, >90% of S. pyogenes isolates were identified as belonging to a single clone, emm type 81, T type 8. Epidemiological investigation revealed that the hygiene levels of the soldiers and their living conditions were probably the most important cause for the difference in attack rates, wound severity, and systemic sequelae found between and within the units.CONCLUSIONS:Our study demonstrates the possible ramifications of the combination of a virulent and highly infective S. pyogenes strain and poor living conditions, and it emphasizes the importance of early intervention in such conditions.

BACKGROUND:West Nile Virus (WNV) is endemic in Israel and a significant level of antibodies is present in the population due to natural exposure. Anecdotal cases suggested that the presence of anti-WNV antibodies in intravenous immunoglobulin (IVIG) from Israeli donors (IVIG-IL) assisted the recovery of patients with severe WNV infection.METHODS:To enhance the therapeutic efficacy of IVIG-IL against WNV infection, OMRIX Biopharmaceuticals, Israel, have developed a strategy for selection of plasma units from a 10% fraction of Israeli blood donors with anti-WNV antibodies. Positive units were processed into pharmaceutical grade WNV IVIG (WNIG). Following inoculation with WNV, mice received i.p. injections of different doses (0.01-8 mg/mouse) of IVIG-IL or WNIG, according to the specific experimental protocol.RESULTS:WNIG was about 10 times more potent (per gr of IgG) than was regular IVIG-IL when tested by ELISA and neutralization assays. In a mouse lethal WNV infection model, prophylactic treatment with WNIG was at least 5-10-fold more potent as compared to treatment with IVIG-IL. Treatment with WNIG during active encephalitis, three or four days following WNV infection, had a significant protective effect. WNIG was also very effective in protecting immunosuppressed mice. Indeed, treatment of dexamethasone-immunosuppressed mice with 0.2 or 1.0 mg WNIG 4 h after virus infection, led to 100% survival.CONCLUSION:IVIG produced from selected plasma donated in WNV endemic regions can be used to produce WNV IVIG with superior activity for therapeutic and prophylactic measures.

The pulsed submerged arc is a high-current electrical discharge between two electrodes in a liquid, in which the electrical current is conducted via a plasma bubble consisting of vaporized and partially ionized liquid and electrode material. The submerged arc discharge has the potential to kill harmful pathogens by a combination of several mechanisms. In this preliminary investigation, the ability of the pulsed arc to sterilize water was tested, hydroxyl radical (OH·) production and the radiation spectrum were measured, and shock wave production was estimated.

David Ben-Nathan (davidbn@013.net.il) Orly Gershoni-Yahalom (orlyge@bgu.ac.il) Itzchak Samina (isami@moag.gov.il) Yevgeny Khinich (vaccine@moag.gov.il) Israel Nur (israel@omrix.co.il) Orgad Laub (orgad@omrix.co.il) Ahuva Gottreich (ahuva@sheba.health.gov.il) Michael Simanov (vaccine@moag.gov.il) Angel Porgador (angel@bgu.ac.il) Bracha Rager-Zisman (rager@netvision.net.il) Nadav Or (nadav@omrix.co.il)

The threat of smallpox, and with it smallpox vaccination, ended over 30 years ago. Since September 2001, a limited reintroduction of vaccination was carried out. The development of a skin reaction following vaccina vaccination ("take") remains the sole indicator of immunity acquisition.Current vaccination policy states that immunity acquired from a onetime vaccination remains for less than 10 years and that individuals who fail to develop a "take" after revaccination must be rechallenged. However, historical records show smallpox resistance over 50 years after vaccination. Furthermore, recent studies have found that levels of vaccinia-specific B-cells and antibodies remain constant (after the decline of the initial reaction peak) over many decades while the T-cell levels steadily decline (half-life of 14 years) but are still identifiable for at least 50 years. A direct correlation has been observed between high anti-vaccinia antibody levels, immunity against vaccinia and variola, and lack of "take" during revaccination. These findings are strengthened by observations of immunity to vaccina illness in animals and humans lacking T-cell response (due to HIV syndrome or genetic defects), given high pre-exposure antibody levels.This data indicates a central role for B-cells in maintaining immune protection from smallpox with a contributing role for T-cells as a memory component, and the problems inherent in determining the need for revaccination and evaluating new vaccines on the basis of the "take" indicator. Old and new findings have significant implications on evaluation of current herd immunity and prioritization in case of resumed vaccination.