Birdlife, a tourist attraction for the southern portion of Bacalar Lagoon, Quintana Roo, Mexico

The Bacalar Lagoon (BL) in Quintana Roo, Mexico; is an area of high interest due to its tourist potential. However, the changes in landuse patterns, urbanization, extensive cattle ranching and rapidly expanding agriculture, have generated negative impacts on areas of adjacent plan communities and wildlife habitats. The objective of this study has to evaluate the level of vegetation conservation in the southern portion of the BL through the avifauna present in sites with contrasting degrees of conservation. Additionally, change "and their habitat preference(s) in the different communities" to and their habitat use preferences in the different communities. To evaluate the level of conservation of the BL, field visits and botanical collections were carried out to identify species. For the counting and identification of birds, monthly surveys were made through coastal tours along the cenote Xul-ha in 2.5 km transects. Four transects were established: two for sites characterized as semi-conserved and two with disturbed sites. A total richness of 40 taxa was observed, which corresponds to 8.1% of the Quintana Roo avifauna and 32% to wetland birds (125 species). The species accumulation curves indicated that semi-conserved and disturbed sites tend to reach asymptotes and with a coverage percentage greater than 90%. In terms of diversity and community structure, no significant differences were observed. However, the semi-conserved and disturbed sites each have 11 unique species and share 18 species. The LB has an intermediate diversity of bird species compared to studies at the Mexican level, the habitat is important for the conservation of birdlife; as it functions as a reservoir of diversity. Strategies has been suggested that promote sustainable tourism, support the restoration of natural vegetation; and facilitate the economic development of the region.

A multi-scale agent-based model for avascular tumour growth

In this paper, we have developed a multi-scale, lattice-free, agent based model of avascular tumour growth in epithelial tissue. The model integrates different events to identify the underlying diversity within intracellular, cellular, and extracellular layer dynamics. The model considers every cell as an agent. A cellular agent may proliferate, spawns two identical daughter agents, or it may be transformed into other phenotypes during its life time depending on its internal proteins' activity as well as its external microenvironment. In this context, a simplified age-structured cell cycle model is adopted from the existing literature. The model considers that the intracellular events are regulated by p27 gene expression. In this model, p27 protein controls the overall tumour growth dynamics. Moreover, p27 is controlled by the external oxygen and nutrients that are modelled with the reaction-diffusion equations. The model also considers several biophysical forces which directly effect on the tumour growth dynamics. This modelling framework offers biologically realistic outcomes and also covers important criteria of the hallmarks of cancer which include oxygen and nutrient consumptions, micro-environmental heterogeneity, tumour cell proliferation by avoiding growth suppressor signals, replication of tumour cells at an abnormally faster rate, and resistance of apoptosis. The avascular tumour growth model is validated with immunohistochemistry and histopathology data. The outcome of the proposed model is very close to the range of the patient data, which concludes that the model is capable enough to mimic these complex biophysical phenomena.

Avascular tumour growth models based on anomalous diffusion

In this study, we model avascular tumour growth in epithelial tissue. This can help us to understand that how an avascular tumour interacts with its microenvironment and what type of physical changes can be observed within the tumour spheroid before angiogenesis. This understanding is likely to assist in the development of better diagnostics, improved therapies, and prognostics. In biological systems, most of the diffusive processes are through cellular membranes which are porous in nature. Due to its porous nature, diffusion in biological systems are heterogeneous. The fractional diffusion equation is well suited to model heterogeneous biological systems, though most of the early studies did not use this fact. They described tumour growth with simple diffusion-based model. We have developed a spherical model based on simple diffusion initially, and then the model is upgraded with fractional diffusion equations to express the anomalous nature of biological system. In this study, two types of fractional models are developed: one of fixed order and the other of variable order. The memory formalism technique is also included in these anomalous diffusion models. These three models are investigated from phenomenological point view by measuring some parameters for characterizing avascular tumour growth over time. Tumour microenvironment is very complex in nature due to several concurrent molecular mechanisms. Diffusion with memory (fixed as well as variable) formation may be an oversimplified technique, and does not reflect the detailed view of the tumour microenvironment. However, it is found that all the models offer realistic and insightful information of the tumour microenvironment at the macroscopic level, and approximate well the physical phenomena. Also, it is observed that the anomalous diffusion based models offer a closer description to clinical facts than the simple model. As the simulation parameters get modified due to different biochemical and biophysical processes, the robustness of the model is determined. It is found that the anomalous diffusion models are moderately sensitive to the parameters.

Smart, Innovative and Intelligent Technologies Used in Drug Designing

Smart and intelligent computational methods are essential nowadays for designing, manufacturing and optimizing new drugs. New and innovative computational tools and algorithms are consistently developed and applied for the development of novel therapeutic compounds in many research projects. Rapid developments in the architecture of computers have also provided complex calculations to be performed in a smart, intelligent and timely manner for desired quality outputs. Research groups worldwide are developing drug discovery platforms and innovative tools following smart manufacturing ideas using highly advanced biophysical, statistical and mathematical methods for accelerated discovery and analysis of smaller molecules. This chapter discusses novel innovative applications in drug discovery involving use of structure-based drug design which utilizes geometrical knowledge of the three-dimensional protein structures. It discusses statistical and physics based methods such as quantum mechanics and classical molecular dynamics which can also play a major role in improving the performance and in prediction of computational drug discovery. Lastly, the authors provide insights on recent developments in cloud computing with significant increase in smart and intelligent computational power thus allowing larger data sets to be analyzed simultaneously on multi processor cloud systems. Future directions for the research are outlined.

Mesenchymal stromal cells derived from acute myeloid leukemia bone marrow exhibit aberrant cytogenetics and cytokine elaboration

Bone marrow-derived mesenchymal stromal cells (BM-MSCs) play a fundamental role in the BM microenvironment (BME) and abnormalities of these cells may contribute to acute myeloid leukemia (AML) pathogenesis. The aim of the study was to characterize the cytokine and gene expression profile, immunophenotype and cytogenetics of BM-MSCs from AML patients compared to normal BM-MSCs from healthy donors. AML BM-MSCs showed decreased monocyte chemoattractant protein-1 levels compared to normal BM-MSCs. AML BM-MSCs expressed similar β1 integrin, CD44, CD73, CD90 and E-cadherin compared to normal BM-MSCs. Cytogenetic analysis revealed chromosomal aberrations in AML BM-MSCs, some overlapping with and others distinct from their corresponding AML blasts. No significant difference in gene expression was detected between AML BM-MSCs compared to normal BM-MSCs; however, comparing the differences between AML and MSCs from AML patients with the differences between normal hematopoietic cells and normal MSCs by Ingenuity pathway analysis showed key distinctions of the AML setting: (1) upstream gene regulation by transforming growth factor beta 1, tumor necrosis factor, tissue transglutaminase 2, CCAAT/enhancer binding protein alpha and SWItch/Sucrose NonFermentable related, matrix associated, actin dependent regulator of chromatin, subfamily a, member 4; (2) integrin and interleukin 8 signaling as overrepresented canonical pathways; and (3) upregulation of transcription factors FBJ murine osteosarcoma viral oncogene homolog and v-myb avian myeloblastosis viral oncogene homolog. Thus, phenotypic abnormalities of AML BM-MSCs highlight a dysfunctional BME that may impact AML survival and proliferation.

Abdominal cocoon

Background The abdominal cocoon syndrome was first described as a rare condition where part of or the whole small bowel is encased within a fibrous membrane. Idiopathic sclerosing encapsulating peritonitis (or abdominal cocoon) is a rare cause of small bowel obstruction, especially in adult population. Diagnosis is usually incidental at laparotomy. But preoperative diagnosis can be made. Case presentation This report is of a 27-year-old Bangladeshi male who presented with increasing abdominal pain and features of subacute intestinal obstruction. He had a history appendicectomy 2 months back through grid iron incision in a peripheral hospital. Pre-operative work-up did not reveal a sac like structure encasing small intestinal loops. At computed tomography of the abdomen and pelvis, a huge cystic structure was seen encasing loops of small bowel. At laparotomy, a fibrous capsule was revealed, in which small bowel loops were encased, with the presence of interloop adhesions. A diagnosis of primary abdominal cocoon was established and extensive adhesiolysis was performed. The patient had an uneventful recovery and follow-up. No evidence of Kochs noted in the abdomen or on histopathology of tissue sent for examination. Conclusion Abdominal cocoon is a rare cause of small bowel obstruction, but should be suspected especially in cases with attacks of non strangulating obstruction in the same individual. A high index of clinical suspicion may be generated by the recurrent character of small bowel obstruction. Clinicians must rigorously pursue a preoperative diagnosis. The overall prognosis is satisfactory. DOI: http://dx.doi.org/10.3329/pulse.v5i2.20269 Pulse Vol.5 July 2011 p.61-64

Haemangioma of the nasal bone

A 16 year-old female presented for her cosmetic deformity with a slowly progressing swelling of insidious onset on the upper part of the bridge of the nose slightly towards the left side for 3 year duration. Clinical & radiological examination revealed an intra-osseous tumor of nasal bone. Histopathologically the tumor was a cavernous haemangioma of nasal bone. A follow up study upto 13-year showed no recurrence. A detailed search of world literature is carried out with clinical history & history of trauma. It could that nasal bone haemangioma is separate disease entity. The patients usually seek advise for their cosmetic deformity & sometime for nasal bleeding.

An arrow in the nasal cavity, ethmoid and nasopharynx

A penetrating foreign body (Metallic arrow) involving the ethmoidal air cells nose and nasopharynx is being reported.

Play safe with safety pins

Three cases of Safety pins in the aerodigestive tract have been presented here with a brief review of litereture.

Proximate Composition and Functional Properties of Mushroom Flours from Ganoderma spp., Omphalotus olearius (DC.) Sing. and Hebeloma mesophaeum (Pers.) Quél. Used in Nasarawa State, Nigeria

The proximate composition and functional properties of three edible mushroom (Ganoderma spp., Omphalotus olearius (DC.) Sing. and Hebeloma mesophaeum (Pers.) Quél.) flours used in Nasarawa state, Nigaria were investigated using standard analytical techniques. The samples contained crude protein in the range of 18.5% in Omphalotus olearius to 21.5% in Ganoderma spp. Crude fat varied with values ranging from 6.9% in Ganoderma spp. to 8.7% in Omphalotus olearius. Other proximate composition values were in the following ranges: moisture content 10.0 - 11.1%, ash 7.3 - 8.3%, crude fibre 2.8 - 3.5% and carbohydrate (by difference) 50.3 - 50.9%. The range values of functional properties were: foaming capacity 101.8 - 131.5%, foaming stability 51.0 - 54.0%, water absorption capacity 260.0 - 390.0%, oil absorption capacity 450 - 480%, oil emulsion capacity 57.3 - 61.0mLg- 1, least gelation concentration 12.0 - 14.0% and bulk density 230.0 - 410.0gmL-1. The results showed that these nutrient rich mushroom flours under investigation may prove useful in the formulation of different food products where foaming, emulsification, retention of flavour and palatability as well as gel formation are required.

Foreign body in ENT--general practitioner's duty

Foreign body in ENT region is an age-old problem. Introduction of foreign body in ear, nose and throat is specially seen in children. There are many types of foreign body seen in the ear, nose and throat. They can aspirate into larynx, trachea and bronchus. How to manage the removal of foreign body in ear, nose and throat had been discussed in a nutshell. General practitioners should be skilled enough to remove foreign body with their limited resources and they should know when to send the cases to an ENT specialist or to a hospital.

Manufacturing techniques and excipients used during the design of biodegradable polymer-based microspheres containing therapeutic peptide/protein for parenteral controlled drug delivery

In the last couple of decades, use of biodegradable polymer-based microspheres has been recognized as an interesting and promising approach for parenteral controlled delivery of therapeutic peptide/protein, including antigens. The main objectives of this review are (i) to update the current state of art of manufacturing of peptide/protein-loaded microspheres through both conventional and newer microencapsulation techniques, and (ii) to bring into focus the various possible instability problems, and the investigated mechanistic ways to obviate the instability problems of peptide/protein drug during microspheres preparation as well as its release from the microspheres. The solubilization, stabilization, and preservation enhancing excipients that are used in peptide/protein-loaded microspheres are briefly overviewed.

Merkel cell carcinoma: a case report

Merkel cell carcinoma is an uncommon, highly malignant, primary cutaneous neuroendocrine tumour mostly occurring as a solitary nodule on the head or on the extremities. It has high recurrence rate. We hereby report a case of Merkel cell carcinoma in a young woman.

Tumoral calcinosis--clinicopathological study of five cases

Five cases of tumoral calcinosis were studied during the period of January-february 1999 in MIMER medical college, Talegaon, a rural place 35kms. from Pune. All the Five patients were females residing in nonendemic area for Dracunculosis. They were from 5th-6th decade. They were otherwise healthy and had normal serum calcium and phosphorus levels and no eosinophilia. All had large, hard subcutaneous lump around hip joint. The skin overlying the swelling was normal. Histologically all cases showed similar morphology, the lesions were composed of large and small deposits of calcium. The foreign-body giant cell reaction was seen in two cases. There were no eosinophils and lymphocytes. On multiple sectioning none of the cases revealed any evidence of dead or living parasite. Old and recent necrosis was absent. These cases are presented since the condition is comparatively rare and it appeared in crops in our Institute.

Role of grommet in otitis media with effusion: A necessity or nuisance? A comparative study

Otitis media with effusion is one of the commonest otological problems in paediatric age group. The condition occurs in childhood as overt or covert hearing loss presenting as an educational or behavioural problem. As there is widespread controversy regarding its precise aetiology, natural history and pathogenesis a treatment dilemma still persists. The main goal of this study is to compare the efficacy of different modalities of medical and surgical treatment designed for this condition and analysis of the results statistical.

Binding of diclofenac sodium with bovine serum albumin at different temperatures, pH and ionic strengths

The study was designed to examine the binding of diclofenac sodium with bovine serum albumin (BSA) at different temperatures (20 degrees, 30 degrees and 40 degrees C), pH (6.4, 7.4 and 8.4) and ionic strengths (micro = 0.1, 0.2 and 0.3) by means of equilibrium dialysis method. The concentration of diclofenac sodium was maintained at wider range from 15 to 900 micromole/l and BSA concentration was maintained at 61.5 micromole/l. The data obtained were interpreted by nonlinear regression method using Graphpad prism software. The analysis showed that the interaction between diclofenac sodium with BSA results in two-site saturable binding. A decrease in association constant was observed with increasing temperature. The average standard free energy change (deltaGdegrees) value was -7.07 (site I) and -4.2 (site II) Kcal/mol. The standard enthalpy change (deltaHdegrees) and the standard entropy change (deltaSdegrees) were -7.8 Kcal/mole, -2.35 cal/mole (site I) and -7.4 Kcal/mole, -10.5 cal/mole (site II), respectively. The negative enthalpy change suggested the binding between diclofenac sodium and the binding sites of BSA were spontaneous and exothermic. The negative value of deltaHdegrees and deltaSdegrees indicated hydrogen bonding and van der Waal's force was the major mechanism for diclofenac sodium and BSA interaction. Increase in pH and ionic strength also caused decrease in association constant of diclofenac sodium and BSA binding.

Acute toxicity and diuretic studies of Rungia repens aerial parts in rats

Ethanolic extract of Rungia repens aerials parts (300 and 600 mg/kg p.o) showed diuretic activity in rats. The acute toxicity, orally evaluated in mice, was found to be higher than 3000 mg/kg.

Effect of sulfidogenic and methanogenic inhibitors on reductive dehalogenation of 2-chlorophenol

The potential for reductive dehalogenation of 2-CP in anaerobic batch cultures of fresh-water digested sludge under sulfidogenic and methanogenic conditions was investigated in the presence or absence of respective inhibitors: molybdate and BESA at various concentrations (0 to 10 mM). Triplicate cultures (50% vol/vol) were set-up under an atmosphere of 20% CO2 and 80% N2 in 160 ml serum bottles using anaerobic digester sludge and a mineral medium containing 0.1% yeast extract. The dehalogenation of 2-CP, as well as methanogenesis, occurred at the same rate in the presence or absence of sulphate. Sulphate reduction did not inhibit 2-CP degrading populations. The presence of BESA--a known inhibitor of methane producers partially inhibited methanogenesis and slowed 2-CP dehalogenation at even 1 mM concentration with phenol and acetate accumulation in the cultures. The accumulation was proportional to the increase in concentration of BESA in the system. Molybdate on the other hand completely inhibited both sulphate reduction and 2-CP dehalogenation at a concentration of 10 mM. The dehalogenation of 2-CP continued in the presence of 1 mM molybdate even after the cessation of sulphate reduction indicating that sulphate-reducing bacteria were not directly involved in the dehalogenation of 2-CP in this study. Inhibition of 2-CP dehalogenation and sulphate reduction along with accumulation of propionate at 10 mM molybdate in the cultures strongly suggests that the dehalogenation of 2-CP was more directly linked to syntrophic activity of the mixed culture compared to sulphate reduction.

Deaf child--a general practitioner's responsibility

The power of a child's speaking language never develops if he is deaf. Deafness persists if it is not detected early. Childhood deafness is either congenital or acquired. At birth, doctors or attendants can detect deafness by arousing the baby with sudden loud noise. At 4 months onwards mothers and doctors can detect deafness. The baby at this age can turn its head or eyes towards the source of the sound. By 12 months to 2 years of age it is very difficult to detect deafness. By the age of 3 years children again become co-operative and it becomes easier to detect deafness. Children should always be screened for deafness while being admitted to nursery classes. In school going age ie, 5 years onwards loss of tests can be employed to detect deafness. If a child is suspected be deaf, a general practitioner's responsibility is to refer him to an ENT specialist earlier. Any child whose mother believes her child is deaf should be given due attention. Otitis media with effusion, enlarged adenoid, chronic suppurative otitis media, recurrent otitis media are some diseases to be carefully looked into by the general practitioners. Now-a-days cochlear implantation surgery is gaining popularity to give hearing to deaf child. Moreover regular screening for deafness should be included school heath programme.

Mason diabetes--report of a family

A 48-year-old Hindu housewife was presented with increased appetite, thirst, frequency of micturition, weakness, cramps in the legs, tingling in the fingers, decline in bladder-bowel control and dimness of vision. She was a patient of diabetes. On investigations and history, she was diagnosed as a case of type 2 diabetes transmitted in three generations as an autosomal dominant trait.

A novel gene encoding a 54 kDa polypeptide is essential for butane utilization by Pseudomonas sp. IMT37

Twenty-three propane- and butane-utilizing bacteria were isolated from soil samples collected from oilfields. Three of them have been identified as Rhodococcus sp. IMT35, Pseudomonas sp. IMT37 and Pseudomonas sp. MT40. SDS-PAGE analysis of the membrane of Rhodococcus sp. IMT35 revealed the presence of at least four polypeptides induced by propane. Polyclonal antibody raised against a 58 kDa polypeptide from Rhodococcus sp. IMT35 specifically detected bacteria which were actively utilizing propane or butane. Immunoscreening of a genomic library in lambdagt11 with this antibody resulted in isolation of a clone containing a 4.9 kb EcoRI genomic DNA fragment. This 4.9 kb DNA fragment was found to hybridize specifically with organisms which could grow on propane or butane. This fragment could therefore be used as a probe for detection of such bacteria. A 2.3 kb fragment having an ORF encoding a polypeptide of 54 kDa was identified by screening a genomic library of Pseudomonas sp. IMT37 with this 4.9 kb EcoRI fragment. The sequence of the ORF (designated orf54) was found to be novel. Primer extension and S1 nuclease mapping showed that transcription of the ORF starts at base 283 and it had sequences upstream similar to that of a Pseudomonas promoter (-12, -24 type). Disruption of the ORF by a kanamycin ('kan') cassette prevented the organism from growing on any alkane but did not affect its ability to utilize the respective alkanols and acids, indicating that alcohol dehydrogenase and subsequent steps in the pathway remained unaltered. The mutants had no detectable level of butane monooxygenase activity. Therefore, the product of this gene plays a crucial role in the first step of the pathway and is an essential component of monooxygenase. The findings imply that this bacterium either employs a common genetic and metabolic route or at least shares the product of this gene for utilization of many alkanes.

Bilateral antrochoanal polyps

An extremely rare case of bilateral antrochoanal polyp in an otherwise fit 12-year-old girl is reported. The antrochoanal polyps were removed by bilateral Caldwell-Luc operation. Histopathological examination showed them to be of benign inflammatory nature.

Air-interface condition promotes the formation of tight corneal epithelial cell layers for drug transport studies

PURPOSE

To identify the growth conditions that would favor the development of a functional primary culture of pigmented rabbit corneal epithelial cells on a permeable support comparable to the intact tissue in bioelectric properties.

METHODS

Rabbit corneal epithelial cells were isolated and cultured on precoated fibronectin/collagen/laminin permeable filters. Cells were grown at an air-interface with supplemented DMEM/F12 medium. Immunofluorescence and electron microscopy techniques, respectively, were used to confirm cornea-specific marker and morphological features. Permeability of the cell layers to model polar compounds was evaluated using 14C-mannitol, fluorescein isothiocyanate (FITC) and fluorescein isothiocyanate-dextran of 4,000 molecular weight (FD4).

RESULTS

We found that culturing the epithelial cells at an air-interface (AIC) was a critical factor in the formation of tight cell layer and that omitting fetal bovine serum and keeping the concentration of epidermal growth factor at 1 ng/ml were equally important. Phenotypically, the AIC cell layers were found to express cornea-specific 64 kD keratin. Compared with cells cultured under the liquid-covered (LCC) condition, those cultured under AIC exhibited a significantly higher peak transepithelial electrical resistance (TEER) of up to 5 kOhm x cm2, a higher potential difference (PD) of up to 26 mV, and an estimated short-circuit current (Ieq) of 5 microA/cm2 after 7-8 days of culture. These values were comparable to those in the excised cornea. Consistent with the TEER, the AIC cell layers were 4-40 times less permeable to paracellular markers than their LCC counterpart.

CONCLUSIONS

The AIC model merits further characterization of drug transport mechanisms as well as drug, formulation, physiological, and pathological factors influencing corneal epithelial drug transport.

Live Salmonella modulate expression of Rab proteins to persist in a specialized compartment and escape transport to lysosomes

We investigated the intracellular route of Salmonella in macrophages to determine a plausible mechanism for their survival in phagocytes. Western blot analysis of isolated phagosomes using specific antibodies revealed that by 5 min after internalization dead Salmonella-containing phagosomes acquire transferrin receptors (a marker for early endosomes), whereas by 30 min the dead bacteria are found in vesicles carrying the late endosomal markers cation-dependent mannose 6-phosphate receptors, Rab7 and Rab9. In contrast, live Salmonella-containing phagosomes (LSP) retain a significant amount of Rab5 and transferrin receptor until 30 min, selectively deplete Rab7 and Rab9, and never acquire mannose 6-phosphate receptors even 90 min after internalization. Retention of Rab5 and Rab18 and selective depletion of Rab7 and Rab9 presumably enable the LSP to avoid transport to lysosomes through late endosomes. The presence of immature cathepsin D (48 kDa) and selective depletion of the vacuolar ATPase in LSP presumably contributes to the less acidic pH of LSP. In contrast, proteolytically processed cathepsin D (M(r) 17,000) was detected by 30 min on the dead Salmonella-containing phagosomes. Morphological analysis also revealed that after uptake by macrophages, the dead Salmonella are transported to lysosomes, whereas the live bacteria persist in compartments that avoid fusion with lysosomes, indicating that live Salmonella bypass the normal endocytic route targeted to lysosomes and mature in a specialized compartment.

Scavenger receptor-mediated delivery of muramyl dipeptide activates antitumor efficacy of macrophages by enhanced secretion of tumor-suppressive cytokines

We showed that muramyl dipeptide (MDP) conjugated to maleylated bovine serum albumin (MBSA) was internalized by macrophages (Mphi) through scavenger receptor (SCR)-mediated endocytosis, which leads to 50-fold higher cytotoxic activity against non-Mphi tumor cells compared with that elicited by free MDP-treated Mphi. The enhanced cytotoxic effect of MBSA-MDP was found to be a result of higher secretion of interleukin (IL)-1, IL-6, tumor necrosis factor alpha (TNF-alpha), and nitric oxide (NO) because the addition of antibodies directed against IL-1, IL-6, or TNF-alpha in combination with Mphi cultures totally abrogated the tumoricidal activity of MBSA-MDP. It is interesting to note that MBSA-MDP triggers the secretion of IL-12, whereas IL-10, a Mphi suppressor cytokine, could be detected only on free MDP treatment. The cytotoxic activity of MBSA-MDP was inhibited by indomethacin, indicating a regulatory role for prostaglandin E2 (PGE2). Efficient SCR-mediated intracellular delivery of MDP leading to elimination of cancer cells suggests the immunotherapeutic potential of this approach for treatment of neoplasia.

Selective activation of antitumor activity of macrophages by the delivery of muramyl dipeptide using a novel polynucleotide-based carrier recognized by scavenger receptors

We have shown that muramyl dipeptide (MDP) conjugated to a 10-mer polyguanylic acid (PolyG) is specifically internalized by macrophages through scavenger receptor (SCR)-mediated endocytosis. Macrophages activated by PolyG-MDP displayed about 20-fold higher cytotoxic activity against nonmacrophage tumor cells compared to that elicited by free MDP. The PolyG-MDP was found to trigger the secretion of higher levels of interleukin-6, interleukin-1alpha, TNF-alpha, and nitric oxide in comparison to free MDP. Addition of antibodies directed against IL-6 and TNF-alpha to macrophage culture completely abrogated the tumoricidal response of PolyG-MDP, indicating that these two cytokines are primarily responsible for bioefficacy. This general approach of PolyG as a vehicle may find wide application in the delivery of genes and antisense oligonucleotides to macrophages.

Disruption of T cell tolerance to self-immunoglobulin causes polyclonal B cell stimulation followed by inactivation of responding autoreactive T cells

Scavenger receptor (SR)-specific delivery by maleylation of a ubiquitous self-protein, Ig, to SR-bearing APCs results in self-limiting induction of autoimmune effects in vivo. Immunization with maleyl-Ig breaks T cell tolerance to self-Ig and causes hypergammaglobulinemia, with increases in spleen weight and cellularity. The majority of splenic B cells show an activated phenotype upon maleyl-Ig immunization, leading to large-scale conversion to a CD138+ phenotype and to significant increases in CD138-expressing splenic plasma cells. The polyclonal B cell activation, hypergammaglobulinemia, and autoreactive Ig-specific T cell responses decline over a 2-mo period postimmunization. Following adoptive transfer, T cells from maleyl-Ig-immune mice taken at 2 wk postimmunization can induce hypergammaglobulinemia in the recipients, but those taken at 10 wk postimmunization cannot. Hypergammaglobulinemia in the adoptive transfer recipients is also transient and is followed by an inability to respond to fresh maleyl-Ig immunization, suggesting that the autoreactive Ig-specific T cells are inactivated peripherally following disruption of tolerance. Thus, although autoreactive T cell responses to a ubiquitous self-Ag, Ig, are induced by SR-mediated delivery to professional APCs in vivo resulting in autoimmune pathophysiological effects, they are effectively and rapidly turned off by inactivation of these activated Ig-specific T cells in vivo.

Improved efficacy and safety of controlled-release diltiazem compared to nifedipine may be related to its negative chronotropic effect

The objective of this study was to assess the safety and efficacy of long-acting preparations of two commonly used calcium antagonists with particular reference to their effects on heart rate. Twenty patients with chronic stable angina were recruited to a double-blind, double-dummy crossover study of controlled-release diltiazem (diltiazem CR) versus sustained-release nifedipine (nifedipine SR) and underwent clinical assessment, symptom and adverse event reporting, and repeated treadmill exercise tests over a 10- to 11-week period. The main outcome measures were heart rate at rest and exercise, incidence of angina and nitroglycerin use, treadmill exercise performance (duration, time to angina, time to 1-mm ST-segment depression, heart rate at equivalent maximal exercise, and maximal ST-segment depression), and adverse events. Diltiazem CR significantly reduced heart rate at rest and equivalent exercise and incidence of angina and nitroglycerin use compared with nifedipine SR. Exercise duration time to angina and time to 1-mm ST-segment depression (but not maximal ST-segment depression) were all significantly improved by diltiazem CR. Diltiazem CR also caused significantly fewer adverse events than nifedipine SR. Calcium antagonists with negative chronotropic effects (eg, diltiazem CR) are safer and more efficacious as monotherapy in chronic stable angina than dihydropyridines (eg, nifedipine SR) even when a long-acting formulation of the latter is used.

Biopharmaceutics of transmucosal peptide and protein drug administration: role of transport mechanisms with a focus on the involvement of PepT1

Non-invasive delivery of peptide and protein drugs will soon become a reality. This is due partly to a better understanding of the endogenous transport mechanisms, including paracellular transport, endocytosis, and carrier-mediated transport of mucosal routes of peptide and protein drug administration. This paper focuses on work related to the elucidation of structure-function, intracellular trafficking, and regulation of the intestinal dipeptide transporter, PepT1.

Oligonucleotides tethered to a short polyguanylic acid stretch are targeted to macrophages: enhanced antiviral activity of a vesicular stomatitis virus-specific antisense oligonucleotide

The poor membrane permeability of oligonucleotides is one of the major problems of antisense technology. Here we report the construction of designer oligonucleotides for targeted delivery to macrophages. The oligonucleotides tethered to a 10-mer poly(G) sequence at their 3' ends were recognized by scavenger receptors on macrophages and were taken up about 8- to 10-fold as efficiently as those oligonucleotides that either lacked a poly(G) tail or that contained a 10-mer poly(C) tail instead of the poly(G) tail. The enhanced uptake of poly(G) constructs was inhibited in the presence of poly(G) and other known ligands of the scavenger receptor. The bioefficacy of poly(G)-mediated targeting of antisense oligonucleotides (ANS) was demonstrated by using vesicular stomatitis virus (VSV) as a model system. The ability of ANS directed against the translation initiation site of N protein mRNA of VSV to inhibit virus replication was assessed. The ANS with the 10-mer poly(G) sequences (ANS-G) brought about significant inhibition of VSV replication in J774E cells (a murine monocyte/macrophage cell line) and Chinese hamster ovary (CHO) cell transfectants expressing scavenger receptors. The ANS lacking a 10-mer poly(G) stretch were ineffective. The inhibition of VSV replication due to ANS-G was completely abrogated in the presence of 10-mer poly(G), indicating that the antisense effect of the ANS-G molecule was a consequence of scavenger receptor-mediated enhanced uptake. Importantly, antisense molecules linked exclusively by natural phosphodiester bonds were as bioeffective as those synthesized with a mixed backbone of phosphodiester and phosphorothioate. Taken together, these results suggest that macrophage-directed designer ANS against infective agents may simply be obtained by adding a short stretch of guanylic acid sequence to the desired specific ANS during solid-phase synthesis. This nucleic acid-based strategy, which utilizes homogeneous preparation of ANS, may find applications in directed manipulation of macrophage metabolism for a variety of purposes as well as in therapy of a broad spectrum of macrophage-related disorders amenable to the antisense approach.

Survey of termite-inhabited soil and mosquito breeding sites in Lucknow, India for potential mycopathogens of Anopheles stephensi

During a short survey of soil and mosquito breeding sites in Lucknow, India for potential mycopathogen from a period of August-October 1996, 11 species of fungi in 5 genera were isolated using live mosquito larvae as host, Aspergillus flavus, A. fumigatus and Fusarium semitectum were the most frequently isolated species. Other fungi recorded were A. niger, A. ochraceus, A. terreus, A. versicolor, Geotrichum candidum, Penicillium verrucosum, Paecilomyces sp. and Fusarium sp. (Liseola/Elegans complex). Insect cell walls are known to contain chitin, so fungal isolates were tested for their chitinase activity on semi synthetic medium containing colloidal chitin. High chitinolytic activities were observed with A. flavus and A. ochraceus. Chitinase producers can be considered as potential pathogens. However, the higher incidence of F. semitectum could not be explained by inability to utilize chitin.

Foreign bodies in the larynx

Inhalation of foreign body is a serious event. A very small proportion of foreign bodies get impacted in the larnyx. Any [foreign body in the larynx presents usually as a respiratory (emergency, when urgent recognition is required to prevent disaster. Two cases of fish bone impacted in the larynx, one in anteroposterior and another in coronal disposition are presented here along with a brief review of literature.

Production of calcium gluconate by fermentation

Calcium gluconate production by Aspergillus niger was investigated in shake flask, rolling shaker, air-lift reactor and stirred reactor. Growth pattern of the organism and fermentation conditions determined the yield of the product. High calcium gluconate production was achieved in air-lift reactor with pellet form of cell growth at moderate specific growth rate and biomass concentration. In another variation of air-lift reactor, when calcium carbonate was confined to a cellulose membrane, calcium gluconate production was maximum (149 g/L). At higher specific growth rate, obtained in shake flask, despite the formation of cell pellets, product formation was low. Physical separation of particulate calcium carbonate and growing cells favoured product formation. In stirred reactor pulpy mycelial growth was obtained and calcium gluconate production was poor.

MHC class I-restricted presentation of maleylated protein binding to scavenger receptors

Pathways for loading exogenous protein-derived peptides on MHC class I are thought to be present mainly in monocyte-lineage cells and to involve phagocytosis- or macropinocytosis-mediated antigenic leakage into either cytosol or extracellular milieu to give peptide access to MHC class I. We show that maleylation of OVA enhanced its presentation to an OVA-specific MHC class I-restricted T cell line by both macrophages and B cells. This enhanced presentation involved uptake through receptors of scavenger receptor (SR)-like ligand specificity, was TAP-1-independent, and was inhibited by low levels (2 mM) of ammonium chloride. No peptide loading of bystander APCs by maleylated (maleyl) OVA-pulsed macrophages was detected. Demaleylated maleyl-OVA showed enhanced MHC class I-restricted presentation through receptor-mediated uptake and remained highly sensitive to 2 mM ammonium chloride. However, if receptor binding of maleyl-OVA was inhibited by maleylated BSA, the residual presentation was relatively resistant to 2 mM ammonium chloride. Maleyl-OVA directly introduced into the cytosol via osmotic lysis of pinosomes was poorly presented, confirming that receptor-mediated presentation of exogenous maleyl-OVA was unlikely to involve a cytosolic pathway. Demaleylated maleyl-OVA was well presented as a cytosolic Ag, consistent with the dependence of cytosolic processing on protein ubiquitination. Thus, receptor-specific delivery of exogenous protein Ags to APCs can result in enhanced MHC class I-restricted presentation, suggesting that the exogenous pathway of peptide loading for MHC class I may be a constitutive property dependent mainly on the quantity of Ag taken up by APCs.