Identification and characterisation of short chain rhamnolipid production in a previously uninvestigated, non-pathogenic marine pseudomonad.

This study aimed to identify and characterise biosurfactant compounds produced by bacteria associated with a marine eukaryotic phytoplankton bloom. One strain, designated MCTG214(3b1), was isolated by enrichment with polycyclic aromatic hydrocarbons and based on 16S rDNA, and gyrB sequencing was found to belong to the genus Pseudomonas, however not related to P. aeruginosa. Cell-free supernatant samples of strain MCTG214(3b1) at stationary phase showed significant reductions in surface tension. HPLC-MS and NMR analysis of these samples indicated the presence of five different rhamnolipid (RL) congeners. Di-rhamnolipids accounted for 87% relative abundance and all congeners possessed fatty acid moieties consisting of 8-12 carbons. PCR screening of strain MCTG214(3b1) DNA revealed homologues to the P. aeruginosa RL synthesis genes rhlA and rhlB; however, no rhlC homologue was identified. Using the Galleria mellonella larvae model, strain MCTG214(3b1) was demonstrated to be far less pathogenic than P. aeruginosa. This study identifies for the first time a significantly high level of synthesis of short chain di-rhamnolipids by a non-pathogenic marine Pseudomonas species. We postulate that RL synthesis in Pseudomonas sp. MCTG214(3b1) is carried out by enzymes expressed from rhlA/B homologues similar to those of P. aeruginosa; however, a lack of rhlC potentially indicates the presence of a second novel rhamnosyltransferase responsible for the di-rhamnolipid congeners identified by HPLC-MS.

Facilitation of Vaginal Delivery in an Infant with Complete Heart Block Secondary to Maternal Anti-Ro Antibodies.

Congenital heart block (CHB) is a rare disorder that may be associated with a high morbidity and even mortality, with a risk of death both in utero and during infancy. Women with serum titres of anti-Ro and/or anti-La antibodies carry a risk of CHB of 1-5% in their offspring, with a recurrence risk of approximately 20%. We present a case of a 36-year-old female with a pregnancy complicated by congenital heart block. Autoimmune profiling at booking showed she was positive for lupus anticoagulant and anti-Ro antibodies. A fetal echocardiogram at 21 + 3 showed complete heart block. She was monitored throughout the remainder of her pregnancy with serial growth scans, cardiovascular profiling, and BPP scoring. She had a normal vaginal delivery at term to a female infant.

Pivotal role of families in doctor-patient communication in oncology: a qualitative study of patients, their relatives and cancer clinicians.

Families are a unique source of support for many cancer patients. Most advanced communication skills training for oncologists are patient centred and do not cover interactions with family members. The current study used in-depth qualitative interviews of patients, relatives and cancer clinicians with thematic analysis to explore the role of family members in the communication process. Forty-one participants included 10 cancer patients, 10 relatives ensuring proportionate representation of both gender and primary cancer site and 21 doctors representing both medical and surgical oncology. Nineteen of 20 patients and relatives wanted an "open and honest" discussion with their doctors. All patients, relatives and doctors preferred involvement of the family at most stages of cancer treatment. Five themes were identified in relation to communication with family members. The participants highlighted the "importance of family for physical and psychological care," they emphasised the need to "balance patient autonomy and relatives desire to be protective" using varied "negotiating strategies" that are influenced by "socioeconomic circumstances of both patient and family." The doctor-patient-relative communication process was not static with preferences changing over time. The data suggests that communication skills training of cancer clinicians should incorporate modules on better communication with relatives.

Transgenic banana expressing Pflp gene confers enhanced resistance to Xanthomonas wilt disease.

Banana Xanthomonas wilt (BXW), caused by Xanthomonas campestris pv. musacearum, is one of the most important diseases of banana (Musa sp.) and currently considered as the biggest threat to banana production in Great Lakes region of East and Central Africa. The pathogen is highly contagious and its spread has endangered the livelihood of millions of farmers who rely on banana for food and income. The development of disease resistant banana cultivars remains a high priority since farmers are reluctant to employ labor-intensive disease control measures and there is no host plant resistance among banana cultivars. In this study, we demonstrate that BXW can be efficiently controlled using transgenic technology. Transgenic bananas expressing the plant ferredoxin-like protein (Pflp) gene under the regulation of the constitutive CaMV35S promoter were generated using embryogenic cell suspensions of banana. These transgenic lines were characterized by molecular analysis. After challenge with X. campestris pv. musacearum transgenic lines showed high resistance. About 67% of transgenic lines evaluated were completely resistant to BXW. These transgenic lines did not show any disease symptoms after artificial inoculation of in vitro plants under laboratory conditions as well as potted plants in the screen-house, whereas non-transgenic control plants showed severe symptoms resulting in complete wilting. This study confirms that expression of the Pflp gene in banana results in enhanced resistance to BXW. This transgenic technology can provide a timely solution to the BXW pandemic.

Implication of intracellular glutathione and its related enzymes on resistance of malaria parasites to the antimalarial drug arteether.

The control of malaria has been complicated by the increasing resistance of malarial parasites to multiple drugs. However, artemisinin-based drugs offer hope in the fight against drug-resistant parasites. The mode of action of these drugs remains unclear, but evidence suggests a role for free radicals in their mechanism of action. In this study, we examined the relationship between the intracellular levels of glutathione (GSH) and antioxidant enzymes and resistance to the artemisinin-based drug arteether in experimentally selected arteether-resistant Plasmodium vinckei. GSH plays a critical role in the detoxification and protection of cells against oxidative stress. Our comparative studies showed a significant (2.9-fold) increase in the GSH level in arteether-resistant parasites as compared to arteether-sensitive parasites. Simultaneously, significantly increased activities of glutathione reductase, glutathione-S transferase and glucose-6-phosphate dehydrogenase and decreased activity of superoxide dismutase were recorded in resistant parasites; the activity of glutathione peroxidase was comparable in arteether-sensitive and -resistant parasites. Artemisinin derivatives act by generating free radicals and our results indicate that glutathione's antioxidant effects may counteract that drug effect and thereby contribute to the parasites' resistance to arteether and other artemisinin-based antimalarials.

Derivatives of human beta-casein fragments (54-59) exhibit highly potent immunosuppressant activity.

Human beta-casein fragment (54-59) having the amino acid sequence Val-Glu-Pro-Ile-Pro-Tyr, has shown potent immunostimulant activity. Several analogs of this hexapeptide have been synthesized with modification at the N-terminal region and two analogs, viz. peptide I and peptide II have shown significant immunosuppressant activity in-vivo mouse model. Effect on cell mediated immunity (CMI) and humoral immunity was studied in mouse/SRBC model. Both the peptides failed to stimulate immune response in vivo and showed inhibition of CMI and humoral response to sheep red blood cells (SRBC). Peptides showed inhibition in alloantigen induced lymphocyte proliferation, i.e., mixed lymphocyte reaction (MLR) in vitro. Treatment with peptides inhibited the production of interferon-gamma (IFN-gamma), and increased the production of interleukin-4 (IL-4) as well as improved the skin graft survival. Cyclosporine a known immunosuppressant showed similar effect on mouse model. Present study thus provides a lead for the development of safe and effective immunosuppressant.

Immunomodulatory activity of analog of muramyl dipeptide and their use as adjunct to chemotherapy of Leishmania donovani in hamster.

In search of a potent immunomodulator to be used as an immunoprophylactic agent and as adjunct to chemotherapy against Leishmania infection, two analogs of muramyl dipeptide, viz. N.Ac-norMur-MeVal-D-isoGln (86/448) and N.AcMur-Acc-D-isoGln (89/729) were evaluated for desired activity. Effect of these peptides on cell mediated and humoral immunity was studied by immunizing the peptide treated mouse with sheep red blood cells (SRBC) and determining HA-titer, plaque forming cells assay and delayed type of hypersensitivity (DTH) response after 4-5 days. Both the peptides stimulated cell mediated immunity (CMI), humoral response as well as macrophage function in terms of super oxide anion (O2-) and nitric oxide (NO) generation. Mitogen induced lymphocyte proliferation and production of IL-2 and INF-gamma increased while that of IL-4 and IL-10 decreased by both the peptides showing a typical Th1 type response. After establishing the immunostimulatory activity, these peptides were evaluated for immunoprophylactic efficacy as well as for use as adjunct to chemotherapy with stibanate (SSG) against Leishmania donovani infection in golden hamster. These peptides were found quite effective in both the modes. In adjunct use the treatment may require lower dose of SSG and thereby reduce the chances of drug toxicity.

Acanthocheilonema viteae: octopamine and its physiological role.

Octopamine acts as an important neurotransmitter and neuromodulator in arthropods, mollusks, and nematodes. In mammals, however, no definite function for this amine has yet been described. By virtue of this difference in the neurophysiological requirement of the mammalian host and nematodes, octopamine offers good opportunity for exploring this area deeply with a view to identify a unique target for filarial chemotherapy. Results of the present study indicated that Acanthocheilonema viteae, the rodent filarial parasite, utilized tyrosine as a precursor for producing octopamine and some other biogenic amines. Octopamine exhibited specific saturable binding with the membrane prepared from the anterior portion of the filariid. This amine induced concentration dependent increase in the membrane potential which possibly caused tonic paralysis of the filariid. The rate of micro filarial release by the female worms also declined in the presence of this amine. The study thus provided preliminary evidences for the presence of an octopamine neurotransmitter system and also about some of the roles it plays in A. viteae.

Macrophages in the development of protective immunity against experimental Brugia malayi infection.

The present report compares the macrophage function in rodent hosts susceptible and resistant to the human lymphatic filariid Brugia malayi. Macrophages from both mastomys (resistant) and gerbil (susceptible) infected intraperitoneally (i.p.) with the infective larvae (L3) of B. malayi were isolated from peritoneal lavage at different time-intervals and formation rate of NO, H2O2, O2-, TNF-alpha, glutathione peroxidase and reductase was assayed. NO release was found to be significantly increased in resistant mastomys as compared to gerbils and the release was markedly suppressed by i.p. administration of the NOS inhibitor aminoguanidine (AG). The AG-treated mastomys also demonstrated significantly greater establishment of larvae which correlated well with suppressed formation of NO. Nitric oxide synergizes with superoxide to form peroxynitrite radical (potent oxidant), which is known to be more toxic per se than NO. Results indicate the possible involvement of peroxynitrite in the rapid killing of larvae in the peritoneal cavity of mastomys. In contrast, the production of H2O2 was found to be enhanced in both species indicating that B. malayi L3 could withstand the toxic effects of H2O2. The higher level of glutathione peroxidase and reductase, as observed in mastomys compared with the gerbil after larval introduction, possibly protects the cell against the injurious effect of H2O2. The TNF-alpha level remained virtually unchanged in both the hosts, suggesting an insignificant role for this cytokine in parasite establishment.

Modulation of inflammatory mediators by ibuprofen and curcumin treatment during chronic inflammation in rat.

Inflammation is a protective tissue response occurring in three distinct phases, acute, subacute and a chronic proliferative phase. We undertook the present study to understand the overall immune response of the body during adjuvant induced chronic inflammation in rat and the effect of ibuprofen and curcumin on this response. Inflammatory mediators were estimated on day 21 and day 35 after adjuvant injection. The level of C-reactive protein increased to 200% on day 21 and then reduced to 50% on day 35 compared to control. Curcumin and ibuprofen further reduced the increased levels at both the time intervals. Haptoglobin level decreased to 42% on day 21 but increased to 5 times of control on day 35. Curcumin and ibuprofen reduced the increased levels at day 35. No significant change was observed in Prostaglandin-E2 and Leukotriene-B4 levels and in Lymphocyte proliferation. The level of Tumor Necrosis Factor-alpha increased by three folds on day 21, but came down to 88% on day 35. Ibuprofen treatment decreased the raised level on day 21 and increased the reduced level on day 35. Interleukin-1beta increased to 2 folds on day 21 and 10 folds on day 35 which were significantly brought down by curcumin and ibuprofen. Nitric oxide level was reduced at both the time intervals, which were increased by drug treatment.

Acute renal failure due to intrinsic renal diseases: review of 1122 cases.

In this study we have analyzed incidence, causes and clinical course of ARF due to primary intrarenal disease other than acute tubular necrosis. Thousand hundred and twenty two cases of ARF of diverse etiology were studied over a period of 16 years; July 1984 to Dec, 1999. Surgical ARF 231 (20.6%) were not included in the present study. Intrinsic renal diseases were responsible for ARF in 891 (79.4%) of cases. The most common intrinsic renal diseases 705 (79.4%) causing ARF were ischemic/toxic acute tubular necrosis, but not included in this study. Acute renal failure was related to acute glomerulonephritis (9.3%), acute interstitial nephritis (7%), and renal cortical necrosis in (4.6%) of cases. Therefore intrinsic renal diseases other than ATN were the causative factor for acute renal failure in 186 (20.8%) patients in our study. Crescentic (51.8%) and endocapillary proliferative glomerulonephritis (34.9%), were the main glomerular diseases responsible for ARF and 75.9% of GN was related to infectious etiology. Fifty three percent of acute interstitial nephritis was drug induced and in 25 (40%) patients it was related to an infectious etiology. Renal cortical necrosis due to HUS was observed in 16 (39%) children and majority (76.47%) of the cases had a diarrhoeal prodrome. Obstetrical complications were the main causes (61%) of cortical necrosis in adults with acute renal failure. Thus, intrinsic renal diseases other than ATN were responsible for ARF in 186 (20.8%) cases. Post-infectious glomerulonephritis, acute interstitial nephritis and renal cortical necrosis (complicating HUS in children and obstetrical complications in adult) are the main causes of acute renal failure in our study. Both acute GN and interstitial nephritis had excellent prognosis, however renal cortical necrosis was associated with a very high mortality.

Leading Article - Role of biotechnology in medicinal plants

Medicinal plants are the most important source of life saving drugs for the majority of the world's population. The biotechnological tools are important to select; multiply and conserve the critical genotypes of medicinal plants. In-vitro regeneration holds tremendous potential for the production of high-quality plant-based medicine. Cryopreservation is long-term conservation method in liquid nitrogen and provides an opportunity for conservation of endangered medicinal plants. In-vitro production of secondary metabolites in plant cell suspension cultures has been reported from various medicinal plants. Bioreactors are the key step towards commercial production of secondary metabolites by plant biotechnology. Genetic transformation may be a powerful tool for enhancing the productivity of novel secondary metabolites; especially by Agrobacterium rhizogenes induced hairy roots. This article discusses the applications of biotechnology for regeneration and genetic transformation for enhancement of secondary metabolite production in-vitro from medicinal plants

Syntheses and immunomodulatory activity of 3-O-[2'-hydroxy-3'-N,N-disubstituted aminopropan-1'-yl]-alpha-D-glucofuranoses.

A number of 3-O-[2'-hydroxy-3'-N,N-aminopropan-1'-yl]-alpha-D-glucofuranoses were synthesised by regioselective oxirane ring opening in compound 2 with different secondary amines followed by selective deacetalisation. All the compounds were tested for their immunomodulatory potential in vitro; seven of them expressed significant immunostimulant activity.

Immunomodulatory activity of hexapeptides related to proline rich peptide from colostrum.

Twelve analogues of an immunomodulatory hexapeptide YVPGFP (I) derived from Proline rich peptide (from colostrum) have been synthesized with modifications at positions 2, 4 and 6. In MLR assay one of the analogues exhibited approx 50% inhibition at 0.1 microg/mL concentration in contrast to prednisolone and I which caused around 70 and 20% suppression respectively, at the same concentration.

A novel pentasaccharide from immunostimulant oligosaccharide fraction of buffalo milk.

A processed oligosaccharide mixture of buffalo milk induced significant stimulation of antibody, delayed-type hypersensitivity response to sheep red blood cells in BALB/c mice. This also stimulated non-specific immune response of the animals measured in terms of macrophage migration index. A novel pentasaccharide has been isolated from the oligosaccharide containing fraction having immunostimulant activity of buffalo milk. This compound was isolated by a combination of gel filtration chromatography, silica gel column chromatography of derivatised oligosaccharides while the homogeneity was confirmed by high performance liquid chromatography. The results of structural analyses, i.e. proton nuclear magnetic resonance, fast atom bombardment mass spectrometry, chemical transformations and degradations are consistent with the following structure: GlcNAcbeta(1-->3)Galbeta(1-->4)GlcNAcbeta(1-->3)Gal beta(1-->4)Glc

Immunosuppressant activity in human beta-casein fragment analogs.

Human beta-casein fragment (54-59) having the amino acid sequence Val-Glu-Pro-Ile-Pro-Tyr, has been shown potent immunostimulant activity. Several analogs of this hexapeptide have been synthesized with modification in the N-terminal region and tested for their immunomodulatory activity. Interestingly, two hexapeptides have shown significant immunosuppressant activity.