Establishment of somatic embryogenesis from Gerbera jamesonii Bolus EX. Hook F. through suspension culture

Cell suspension cultures were established from embryogenic callus induced from leaf explants of Gerbera jamesonii Bolus ex. Hook f. Embryogenic callus was induced when leaf explants were cultured on MS medium containing 1.0 to 2.0 mg/L 2,4-D. Cream friable callus was formed within two weeks. Proliferated callus was transferred to MS liquid medium containing 2,4-D with a small concentration of NAA and subcultured at 2 weeks interval. Induction of somatic embryos (globular, heart and torpedo) was observed after 2 weeks of culture. Somatic embryos developed in MS suspension medium containing 1.0 to 2.0 mg/L 2,4-D with 0.1 or 1.0 mg/L NAA and globular embryos were further differentiated into the cotyledonary phase embryos. The addition of amino acids (L-glutamine or L-proline, 5.0 mg/L, respectively) to the culture media, in the range of concentrations tested, yielded higher enhancement of the embryo growth and development. Transfer of individual embryos onto a fresh basal medium with no plant growth regulators was able to achieve complete maturation. Relatively, only a few number of embryos developed shoots and roots when transferred to MS medium supplemented with 2.0 mg/L BAP and 0.5 mg/L NAA in addition to 3% (w/v) sucrose and 0.8% (w/v) agar containing medium. About 11% of somatic embryos were converted to true-to-type fertile plants.Key words: Gerbera jamesonii, embryogenic callus, cell suspension culture, plant growth regulators, amino acid

Effects of benzylaminopurine and naphthalene acetic acid on proliferation and shoot growth of pineapple (Ananas comosus L. Merr) in vitro

This study was conducted to evaluate the pineapple regeneration and shoot growth as affected by 6- benzylaminopurine (BAP) at 2.0 mg/l and naphthalene acetic acid (NAA) at 0.2 mg/l in vitro. BAP and NAA at the concentration of 2.0 and 0.2 mg/l were used in this study. BAP at 2.0 mg/l significantly affected the production of shoots per explant, shoot length and weight. Total shoot length was higher in BAP (2 mg/l) than in control (MS medium without hormone) and NAA (0.2mg/l) after 10, 20, 30, 40, 50 and 60 days incubation period. Total shoot length was highest in BAP in all incubation periods. Total shoot weight was higher in BAP (2 mg/l) and lower in NAA (0.2 mg/l) as compared to MS medium without hormone. The results showed that BAP at the concentration of 2 mg/l was effective for pineapple shoot growth and development.Key words: Pineapple regeneration, shoot growth, 6-benzylaminopurine, naphthalene acetic acid

Neuroma of a double gallbladder: a case report

We report a case of 55 year old male patient who presented with recurrent upper abdominal pain following a laparoscopic cholecystectomy. A subsequent diagnostic laparoscopy revealed the presence of a second gallbladder which was initially missed. The peculiarity of his symptoms can in part be explained by the presence of a traumatic neuroma in his second gallbladder. A subsequent cholecystectomy led to a complete resolution of this patient's signs and symptoms. As far as we know this is the first report in the literature of a traumatic neuroma in a second gallbladder

Development of a perioperative medicine research agenda: a cross sectional survey

BACKGROUND: Post-operative complications are a significant source of morbidity and mortality for patients undergoing surgery. However, there is little research in the emerging field of perioperative medicine beyond cardiac risk stratification. We sought to determine the research priorities for perioperative medicine using a cross sectional survey of Canadian and American general internists. METHODS: Surveys were electronically sent to 312 general internists from the Canadian Society of Internal Medicine and 130 internists from the perioperative medicine research interest group within the US based Society of General Internal Medicine. The questionnaire contained thirty research questions and respondents were asked to rate the priority of these questions for future study. RESULTS: The research topics with the highest ratings included: the need for tight control of diabetes mellitus postoperatively and the value of starting aspirin on patients at increased risk for postoperative cardiac events. Research questions evaluating the efficacy and safety of perioperative interventions had higher ratings than questions relating to the prediction of postoperative risk. Questions relating to the yield of preoperative diagnostic tests had the lowest ratings (p < 0.001 for differences across these categories). CONCLUSION: The results of this survey suggest that practicing general internists believe that interventions studies are a priority within perioperative medicine. These findings should help prioritize research in this emerging field

Differential Modulation of TNF-α–Induced Apoptosis by Neisseria meningitidis

Infections by Neisseria meningitidis show duality between frequent asymptomatic carriage and occasional life-threatening disease. Bacterial and host factors involved in this balance are not fully understood. Cytopathic effects and cell damage may prelude to pathogenesis of isolates belonging to hyper-invasive lineages. We aimed to analyze cell–bacteria interactions using both pathogenic and carriage meningococcal isolates. Several pathogenic isolates of the ST-11 clonal complex and carriage isolates were used to infect human epithelial cells. Cytopathic effect was determined and apoptosis was scored using several methods (FITC-Annexin V staining followed by FACS analysis, caspase assays and DNA fragmentation). Only pathogenic isolates were able to induce apoptosis in human epithelial cells, mainly by lipooligosaccharide (endotoxin). Bioactive TNF-α is only detected when cells were infected by pathogenic isolates. At the opposite, carriage isolates seem to provoke shedding of the TNF-α receptor I (TNF-RI) from the surface that protect cells from apoptosis by chelating TNF-α. Ability to induce apoptosis and inflammation may represent major traits in the pathogenesis of N. meningitidis. However, our data strongly suggest that carriage isolates of meningococci reduce inflammatory response and apoptosis induction, resulting in the protection of their ecological niche at the human nasopharynx

Helicobacter pylori (H pylori) infection in Greece: the changing prevalence during a ten-year period and its antigenic profile

BACKGROUND: To evaluate changes in H pylori infection prevalence in Greece during a ten-year period, and to examine its antigenic profile. METHODS: Three groups of patients were studied. Group O-87: Banked serum samples of 200 consecutive adult outpatients, from the Hepato-Gastroenterology clinic of a teaching hospital at Athens, collected in 1987. Group O-97: Serum samples of 201 similarly selected outpatients from the same Unit, collected in 1997. Group BD-97: Serum samples of 120 consecutive blood donors from the same hospital, collected in 1997. H pylori IgG antibody seroprevalence was studied by a quantitative ELISA. Antigenic profile was studied by western-blot IgG assay, in 62 IgG positive patients of O-97 and BD-97. Results were analyzed by conventional statistics and multivariate regression analysis. RESULTS: The H pylori seroprevalence increased with age in the three tested groups. In O-97, seroprevalence did not differ from that, in BD-97. On the contrary, there was a significant decrease in seropositivity between O-87 and O-97 (59.5% vs 49.2%, p = 0.039). Multiple regression analysis showed that age over 35 years (OR:3.45, 95% CI:1.59–7.49, p = 0.002) and year of patients' selection – that is 1987 or 1997 – (OR:1.73, 95% CI:1.14–2.65 for 1987, p = 0.010), were independent risk factors of H pylori infection. The seroprevalence of CagA+ and VacA+ strains was 77.4% and 58.5%, respectively, and type I(CagA+/VacA+) strains were significantly more common than type II(CagA-/VacA-) strains (59.7% vs 22.6%, p < 0.001). CONCLUSIONS: During a ten-year period, we found a significant decrease of H pylori infection in Greece and our data support the birth cohort phenomenon as an explanation for the age-dependent increase of H pylori infection. The prevalence of CagA and/or VacA positive strains is relatively high, in a country with low incidence of gastric cancer

HIV-Neutralizing Activity of Cationic Polypeptides in Cervicovaginal Secretions of Women in HIV-Serodiscordant Relationships

HIV exposed seronegative (HESN) women represent the population most in need of a prophylactic antiviral strategy. Mucosal cationic polypeptides can potentially be regulated for this purpose and we here aimed to determine their endogenous expression and HIV neutralizing activity in genital secretions of women at risk of HIV infection.Cervicovaginal secretions (CVS) of Kenyan women in HIV-serodiscordant relationships (HESN, n = 164; HIV seropositive, n = 60) and low-risk controls (n = 72) were assessed for the cationic polypeptides HNP1–3, LL-37 and SLPI by ELISA and for HIV neutralizing activity by a PBMC-based assay using an HIV primary isolate. Median levels of HNP1–3 and LL-37 in CVS were similar across study groups. Neither HSV-2 serostatus, nor presence of bacterial vaginosis, correlated with levels of HNP1–3 or LL-37 in the HESN women. However, an association with their partner's viral load was observed. High viral load (>10,000 HIV RNA copies/ml plasma) correlated with higher levels of HNP1–3 and LL-37 (p = 0.04 and 0.03, respectively). SLPI was most abundant in the low-risk group and did not correlate with male partner's viral load in the HESN women. HIV neutralizing activity was found in CVS of all study groups. In experimental studies, selective depletion of cationic polypeptides from CVS rendered the remaining CVS fraction non-neutralizing, whereas the cationic polypeptide fraction retained the activity. Furthermore, recombinant HNP1–3 and LL-37 could induce neutralizing activity when added to CVS lacking intrinsic activity.These findings show that CVS from HESN, low-risk, and HIV seropositive women contain HIV neutralizing activity. Although several innate immune proteins, including HNP1–3 and LL-37, contribute to this activity these molecules can also have inflammatory properties. This balance is influenced by hormonal and environmental factors and in the present HIV serodiscordant couple cohort study we show that a partner's viral load is associated with levels of such molecules

Acute Effects of Nicotine Amplify Accumbal Neural Responses during Nicotine-Taking Behavior and Nicotine-Paired Environmental Cues

Nicotine self-administration (SA) is maintained by several variables, including the reinforcing properties of nicotine-paired cues and the nicotine-induced amplification of those cue properties. The nucleus accumbens (NAc) is implicated in mediating the influence of these variables, though the underlying neurophysiological mechanisms are not yet understood. In the present study, Long-Evans rats were trained to self-administer nicotine. During SA sessions each press of a lever was followed by an intravenous infusion of nicotine (30 µg/kg) paired with a combined light-tone cue. Extracellular recordings of single-neuron activity showed that 20% of neurons exhibited a phasic change in firing during the nicotine-directed operant, the light-tone cue, or both. The phasic change in firing for 98% of neurons was an increase. Sixty-two percent of NAc neurons additionally or alternatively showed a sustained decrease in average firing during the SA session relative to a presession baseline period. These session decreases in firing were significantly less prevalent in a group of neurons that were activated during either the operant or the cue than in a group of neurons that were nonresponsive during those events (referred to as task-activated and task-nonactivated neurons, respectively). Moreover, the session decrease in firing was dose-dependent for only the task-nonactivated neurons. The data of the present investigation provide supportive correlational evidence for two hypotheses: (1) excitatory neurophysiological mechanisms mediate the NAc role in cue-maintenance of nicotine SA, and (2) a differential nicotine-induced inhibition of task-activated and task-nonactivated neurons mediates the NAc role in nicotine-induced amplification of cue effects on nicotine SA