Active immunization with tau epitope in a mouse model of tauopathy induced strong antibody response together with improvement in short memory and pSer396-tau pathology.

Abnormal tau hyperphosphorylation and its aggregation into neurofibrillary tangles are a hallmark of tauopathies, neurodegenerative disorders that include Alzheimer's disease (AD). Active and passive Tau-immunotherapy has been proposed as a therapeutic approach to AD with mixed results. One of the limitations of active immunotherapy may be associated with the mediocre immunogenicity of vaccines that are not inducing therapeutically potent titers of antibodies. The aim of this study was to test the efficacy of an anti-tau vaccine, AV-1980R/A composed of N terminal peptide of this molecule fused with an immunogenic MultiTEP platform and formulated in a strong adjuvant, AdvaxCpG in a Tg4510 mouse model of tauopathy. Experimental mice were immunized with AV-1980R/A and a control group of mice were injected with adjuvant only. Nontransgenic and tetracycline transactivator (tTA) transgenic littermates were included as baseline controls to contrast with the tau phenotype. Active immunization with AV-1980R/A induced very strong anti-tau humoral immune responses in both nontransgenic and transgenic mice with evidence of IgG in brains of AV-1980R/A vaccinated mice. These experimental animals displayed an improvement in short-term memory during a novel object recognition test. However, impairments in other behavioral tasks were not prevented by AV-1980R/A vaccinations. At the same time, high titers of anti-tau antibodies reduced hyperphosphorylated pSer396 tau but did not lower the level of other phosphorylated tau species in the brains of AV-1980R/A vaccinated mice. These data indicate that active immunotherapy with an N-terminal Tau epitope was only partially effective in improving cognition and reducing pathology in the stringent Tg4510 mouse model of tauopathy.

Prevalence of methicillin-resistant Staphylococcus aureus in a tertiary hospital in Nepal.

SETTING: Patan Hospital, Lalitpur, Nepal. OBJECTIVES: To describe 1) the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) and its antibiotic sensitivity pattern; 2) the demographic and clinical characteristics associated with MRSA infections; and 3) the treatment outcomes of in-patients with MRSA infection among patients with S. aureus infection between January 2018 and December 2020. DESIGN: This was a cross-sectional study using electronic and paper-based hospital records of patients with S. aureus infection. RESULTS: Of the 1,804 patients with S. aureus infection, 1,027 patients (57%, 95% CI 55-59) had MRSA. The MRSA were susceptible to vancomycin (100%), linezolid (96%), doxycycline (96%), chloramphenicol (86%) and cotrimoxazole (70%), and resistant to erythromycin (68%), clindamycin (56%), gentamycin (58%), ciprofloxacin (92%) and ofloxacin (91%). The prevalence of MRSA was higher in 2019, among out-patients, and in respiratory samples, and lower in blood samples. Of the 142 in-patients with MRSA, 93% had a successful clinical outcome (cured/improved). CONCLUSION: More than 50% of patients with S. aureus infection had MRSA that were resistant to commonly available antibiotics. This calls for strengthening surveil-lance and good infection control practices in this hospital.

LIEU: Hôpital de Patan, Lalitpur, Népal. OBJECTIFS: Décrire 1) la prévalence de Staphylococcus aureus résistant à la méticilline (MRSA) et son profil de sensibilité aux antibiotiques ; 2) les caractéristiques démographiques et cliniques associées aux infections à MRSA ; et 3) les résultats thérapeutiques des patients hospitalisés atteints d'infection à MRSA parmi ceux atteints d'infection à S. aureus de janvier 2018 à décembre 2020. MÉTHODE: Il s'agissait d'une étude transversale réalisée en utilisant les dossiers hospitaliers électroniques et papiers des patients atteints d'infection à S. aureus. RÉSULTATS: Sur les 1 804 patients atteints d'infection à S. aureus, 1 027 patients (57%, IC 95% 55-59) avaient un MRSA. Les MRSA étaient susceptibles à la vancomycine (100%), au linézolide (96%), à la doxycycline (96%), au chloramphénicol (86%) et au co-trimoxazole (70%), et résistants à l'érythromycine (68%), la clindamycine (56%), la gentamycine (58%), la ciprofloxacine (92%) et l'ofloxacine (91%). La prévalence des MRSA était plus élevée en 2019, parmi les patients ambulatoires, ainsi que dans les échantillons respiratoires. Elle était plus faible dans les échantillons sanguins. Sur les 142 patients hospitalisés avec MRSA, 93% ont connu un résultat clinique favorable (guérison/amélioration de l'état). CONCLUSION: Plus de 50% des patients atteints d'infection à S. aureus avaient un MRSA résistant aux antibiotiques habituellement disponibles. La surveillance et les pratiques de contrôle des infections doivent donc être renforcées dans cet hôpital.

DNA prime-protein boost increased the titer, avidity and persistence of anti-Abeta antibodies in wild-type mice.

Recently, we reported that a DNA vaccine, composed of three copies of a self B cell epitope of amyloid-beta (Abeta(42)) and the foreign T-cell epitope, Pan DR epitope (PADRE), generated strong anti-Abeta immune responses in wild-type and amyloid precursor protein transgenic animals. Although DNA vaccines have several advantages over peptide-protein vaccines, they induce lower immune responses in large animals and humans compared with those in mice. The focus of this study was to further enhance anti-Abeta(11) immune responses by developing an improved DNA vaccination protocol of the prime-boost regimen, in which the priming step would use DNA and the boosting step would use recombinant protein. Accordingly, we generated DNA and recombinant protein-based epitope vaccines and showed that priming with DNA followed by boosting with a homologous recombinant protein vaccine significantly increases the anti-Abeta antibody responses and do not change the immunoglobulin G1 (IgG1) profile of humoral immune responses. Furthermore, the antibodies generated by this prime-boost regimen were long-lasting and possessed a higher avidity for binding with an Abeta(42) peptide. Thus, we showed that a heterologous prime-boost regimen could be an effective protocol for developing a potent Alzheimer's disease (AD) vaccine.

DNA, but not protein vaccine based on mutated BORIS antigen significantly inhibits tumor growth and prolongs the survival of mice.

The ideal immunological target for cancer vaccine development would meet the criteria of tumor specificity, immunogenicity and vital dependency of the tumor on the functional activities of the antigenic target so as to avoid antigenic loss by mutation. Given that at face value the brother of regulator of imprinted sites (BORIS) transcription factor meets these criteria, we have developed a mutant variant of this molecule (mBORIS) that lacks tumorigenic ability, while retaining immunogenic epitopes that elicits responses against histologically irrelevant tumor cells. Here we compared vaccine strategies employing as an immunogen either mBORIS recombinant protein formulated in a strong Th1-type adjuvant, QuilA or DNA encoding this immunogen along with plasmids expressing interleukin (IL)12/IL18 molecular adjuvants. In both groups of vaccinated mice induction of tumor-specific immunity (antibody response, T-cell proliferation, cytokine production, T-cell cytotoxicity) as well as ability to inhibit growth of the aggressive breast cancer cell line and to prolong survival of vaccinated animals have been tested. We determined that DNA, but not recombinant protein vaccine, induced potent Th1-like T-cell recall responses that significantly inhibited tumor growth and prolongs the survival of vaccinated mice. These studies demonstrate that DNA immunization is superior to recombinant protein strategy and provide a clear guidance for clinical development of a cancer vaccine targeting what appears to be a universal tumor antigen.

Differential pulse voltammetric studies of ethidium bromide binding to DNA.

The interaction of ethidium bromide (EtBr) with calf thymus DNA is investigated electrochemically with the use of differential pulse voltammetry (DPV) at two different ionic strengths of a solution (0.154 M and 0.02 M [Na+], pH 7.0). It is revealed that EtBr binds with DNA in more than one way. The appropriate values of constants (K) and number site sizes (n) of EtBr binding to DNA are determined. The values of binding constants are equal to 1.9 x 10(6) and 5.6 x 10(5) M(-1), and number site sizes to 9 and 3.6 for strong interactions at ionic strengths of solutions 0.02 and 0.154 M Na+ at 28 degrees C, respectively. For a weaker interaction, these parameters are equal to 7 x 10(4) and 8 x 10(4) M(-1) and 1.5 and 1 at the mentioned ionic strengths of solutions, respectively. Thus, EtBr interacts with DNA in more than one way--intercalative and electrostatic at low ionic strength, and semi-intercalative and electrostatic at a higher strength of the solution. These results are in good accordance with the ones obtained by spectroscopic (absorption and fluorimetric) methods.

Long-term neonatal heart preservation.

UNLABELLED: Donor availability is a major limiting factor in neonatal heart transplantation. Prolonging donor heart preservation would facilitate distant heart procurement. Forty-two neonatal (1 to 5 days) piglet hearts in seven groups were arrested with cold cardioplegic solutions, stored for 12 hours at 4 degrees C in storage solutions, and reperfused with blood from an adult support pig. The cardioplegic solutions used were a crystalloid solution with potassium chloride 30 mEq/L and bicarbonate (Stanford), the Stanford cardioplegic solution with the addition of calcium (1.2 mmol/L), or an intracellular solution (Sacks) with added glucose. Storage solutions were normal saline, Sacks II, or Sacks II with glucose 20 gm/L. Reperfusion was done with normal blood or modified blood for 20 minutes with superoxide dismutase, catalase, aspartate, glutamate, citrate-phosphate-dextrose, potassium, tromethamine, and 50% dextrose followed by normal blood. Evaluation of stroke work index after 60 minutes of recovery (as percent of control) was performed using the isolated, blood perfused, working heart preparation in all groups: Group I (Stanford cardioplegia, saline storage, normal blood reperfusion) had a recovery of 11%; group II (Stanford + calcium, saline, normal blood) 8%; group III (Stanford + calcium, saline, modified blood, superoxide dismutase 35,000 U/L, catalase 35,000 U/L) 37%; group IV (Stanford + calcium, Sacks II, modified blood, superoxide dismutase 35,000 U/L, catalase 35,000 U/L), 47%; group V (Stanford + calcium, Sacks + glucose, modified blood, superoxide dismutase 35,000 U/L, catalase 105,000 U/L) 89%; group VI (Stanford + calcium, Sacks + glucose, modified blood, superoxide dismutase 150,000 U/L, catalase 150,000 U/L) 107%; group VII (Sacks + glucose, Sacks + glucose, modified blood, superoxide dismutase 35,000 U/L, catalase 105,000 U/L) 115%. CONCLUSIONS: The neonatal heart stored hypothermically for 12 hours tolerates normal blood reperfusion poorly. Modified blood reperfusion markedly improves the recovery. Complete functional recovery was achieved by the intracellular Sacks plus glucose storage solution and modified blood reperfusion with oxygen-derived free radical scavengers (high catalase). Extended preservation of the neonatal heart is feasible.

Prevention of reperfusion injury in the neonatal heart with leukocyte-depleted blood.

Activated leukocytes release oxygen free radicals and cause microvascular occlusion. This experiment tests the hypothesis that reperfusion with leukocyte-depleted blood reduces injury after extended ischemic preservation. An in vitro model consisting of an isolated, working neonatal piglet heart and an adolescent support pig was used. Hearts were arrested with a cold crystalloid cardioplegic solution, excised, and stored in 4 degrees C saline for 12 hours. Two groups were compared. In group 1 piglets (n = 8), reperfused with whole blood, the maximum stroke work index was 0.91 +/- 0.29 x 10(3) erg/gm (mean +/- standard error of the mean). Group 2 piglets (n = 6), reperfused with blood depleted of leukocytes by a polyester filter, had a maximum stroke work index of 11.6 +/- 1.0 x 10(3) erg/gm. This difference was highly significant (p less than 0.0001). Group 1 exhibited severe injury with myofibrillar necrosis, mitochondrial disruption, nuclear chromatin clumping, and moderate interstitial edema. Group 2 had normal ultrastructure on electron microscopic examination. We conclude that reperfusion with leukocyte-depleted blood prevents reperfusion injury and results in excellent myocardial function after long-term heart preservation.

Studies on prolonged acute regional ischemia. VI. Myocardial infarction with left ventricular power failure: a medical/surgical emergency requiring urgent revascularization with maximal protection of remote muscle.

Eighty consecutive patients receiving maximum inotropic and intraaortic balloon support underwent emergency coronary artery bypass grafting 3.4 +/- 1 days (mean +/- standard error) after infarction for severe left ventricular power failure (stroke work index less than 25 gm-m, left atrial pressure greater than 20 mm Hg). All underwent induction of cardioplegia with a 37 degrees C glutamate/aspartate blood cardioplegic solution, multidose cold (4 degrees C) replenishment, and warm reperfusate. Viable areas were grafted first to ensure cardioplegic distribution. Left ventricular power failure was reversed in 94% of patients; 75 of 80 patients had discontinuation of inotropic drugs and intraaortic balloon support. The early mortality rate (less than 30 days) was only 7% (3/45) with early operation (less than 18 hours) and rose to 31% (11/35, p less than 0.05) if operation was delayed more than 18 hours. Six of 14 early deaths were due to progression of preoperative organ failure despite reversal of shock. Eighteen of 66 early survivors died of end-stage heart failure (21/80), a 26% late mortality rate. Nonsurvivors (early and late) had a higher incidence of extending versus evolving infarction (33/64 versus 2/16, p less than 0.05), a longer delay from shock to operation (11/45 versus 24/35, p less than 0.05), more preoperative organ failure (9/9 versus 26/71, p less than 0.05), and a greater incidence of previous infarction (22/43 versus 13/37, p greater than 0.05). Thirty of 45 late survivors (67%) remain physically active. We conclude that left ventricular power failure should be considered a medical/surgical emergency that necessitates prompt angiography and can be reversed in selected patients. Postoperative mortality (early and late) is due principally to delay of operation leading to progression of preoperative organ failure or progression of underlying cardiac disease if infarction becomes established.

Myocardial protection in the neonatal heart. A comparison of topical hypothermia and crystalloid and blood cardioplegic solutions.

UNLABELLED: Myocardial protection achieved during 2 hours of ischemic arrest was evaluated in 45 isolated, blood perfused, neonatal (1 to 5 days) piglet hearts. Comparisons were made among five methods of myocardial protection: Group I, topical cooling; Group II, hyperosmolar (450 mOsm) low-calcium (0.5 mmol/L) crystalloid cardioplegia; Group III, St. Thomas' Hospital cardioplegia; Group IV, cold blood cardioplegia with potassium (21 mmol/L), citrate-phosphate-dextrose (calcium level 0.6 mmol/L), and tromethamine; and Group V, cold blood cardioplegia with potassium alone (16 mmol/L) (calcium level 1.2 mmol/L). Hemodynamic recovery (percent of the preischemic stroke work) after 30 and 60 minutes of reperfusion was 82.9% and 86.7% in Group I, 35.7% (p less than 0.0001) and 43.7% (p less than 0.0001) in Group II, 76.1% and 77.7% in Group III, 67.4% (p less than 0.05) and 60.6% (p less than 0.05) in Group IV, and 110.7% and 100.6% in Group V. CONCLUSIONS: Topical cooling is an effective method of myocardial protection in the neonate. Cold blood cardioplegia with potassium alone and a normal calcium level provides optimal functional recovery. The improved protection obtained with both crystalloid and blood cardioplegia with normal calcium levels suggests an increased sensitivity of the neonatal heart to the calcium level of the cardioplegic solution.

The binding of ethidium bromide with DNA: interaction with single- and double-stranded structures.

The pH-induced helix-coil transition of DNA and its complexes with EtBr is carried out at acidic pH in a wide interval of change of concentration ratio of EtBr/DNA. The binding isotherms of EtBr on double and single-stranded DNA at pH = 7.0 and pH = 3.0 (t = 25(o)C) are obtained by absorption and fluorimetric methods. Binding constants (K) and number of bases (n), corresponding to one binding site were determined. Non fluorescent "strong" complex with ds-DNA at pH = 7.0 and t = 25(o)C as well as "strong" and "weak" complexes with ss-DNA at pH = 3.0 and t = 25(o)C are revealed.

Rapid transfusion after aortic decannulation.

A technique for rapid transfusion after aortic decannulation is presented. This technique facilitates the repair of the aortic cannulation site in difficult circumstances.

Pancreatic cystic endocrine neoplasms.

A rare case of cystic pancreatic endocrine tumor is presented, and the literature is reviewed. The patient was initially misdiagnosed as having a pancreatic pseudocyst, and that condition was managed accordingly. Persistence of the cystic lesion and reoperation led to the correct diagnosis and management. The neoplasm stained positive for glucagon and pancreatic polypeptide, but there were no clinical abnormalities that suggested hyperfunction. All cystic lesions of the pancreas should undergo biopsy at operation, to avoid an erroneous diagnosis of benign pseudocyst. Neoplastic lesions should be resected, not internally drained.

Performance of decentralised facilities in tuberculosis case notification and treatment success in Armenia.

We assessed the performance of decentralised tuberculosis (TB) out-patient centres in tuberculosis (TB) case notification and treatment success in Armenia. An average threshold case notification of ⩾37/100 000 was seen in centres that had higher numbers of presumptive TB patients, where more TB was diagnosed by in-patient facilities and where TB contacts were examined. The number of doctors and/or TB specialists at centres did not influence case notification. Onsite smear microscopy was significantly associated with a treatment success rate of ⩾85% for new TB patients. Addressing specific characteristics of TB centres associated with lower case notification and treatment success and optimising their location may improve performance.

The heterotopic right heart assist transplantation.

Heterotopic heart transplantation has been utilized experimentally and clinically to assist the recipient heart in maintaining either the systemic circulation alone or both the systemic and pulmonary circulations. We describe a model in which the heterotopic heart transplantation is utilized to supply the pulmonary circulation while the recipient heart acts as the systemic ventricle. This procedure might be used for selected patients with complex congenital heart disease. The method we have used in five dogs (16.5 to 23.5 kg) consists of preparation of the donor heart by excision after cardioplegic arrest, ligation of the venae cavae, anastomosis of the donor pulmonary artery (PA) to the donor left atrial appendage, and insertion of a left ventricular (LV) apical Dacron graft connected to a valved aortic allograft. Implantation in the recipient consists of anastomosis of the donor left atrium to the recipient right atrium, anastomosis of the LV apical conduit to the recipient main PA, and anastomosis of the donor aorta to the recipient ascending aorta to supply oxygenated blood to the donor coronary circulation. The recipient right ventricle (RV) in the experimental model is inactivated by inducing tricuspid regurgitation and by ligating the proximal PA. Early survival (3 hours) with stable hemodynamic measurements was obtained in all dogs, with the recipient RV excluded from the circulation and with the donor LV pumping the total systemic venous return to the PA. Pulmonary blood flow was maintained even when the ventricular pressure was raised to systemic levels by narrowing the conduit.(ABSTRACT TRUNCATED AT 250 WORDS)