Tetanus toxoid-loaded transfersomes for topical immunization

Topical immunization is a novel immunization strategy by which antigens and adjuvants are applied topically to intact skin to induce potent antibody and cell-mediated responses. Among various approaches for topical immunization, the vesicular approach is gaining wide attention. Proteineous antigen alone or in combination with conventional bioactive carriers could not penetrate through the intact skin. Hence, specially designed, deformable lipid vesicles called transfersomes were used in this study for the non-invasive delivery of tetanus toxoid (TT). Transfersomes were prepared and characterized for shape, size, entrapment efficiency and deformability index. Fluorescence microscopy was used to investigate the mechanism of vesicle penetration through the skin. The immune stimulating activity of these vesicles was studied by measuring the serum anti-tetanus toxoid IgG titre following topical immunization. The immune response was compared with the same dose of alum adsorbed tetanus toxoid (AATT) given intramuscularly, topically administered plain tetanus toxoid solution, and a physical mixture of tetanus toxoid and transfersomes again given topically. The results indicated that the optimal transfersomal formulation had a soya phosphatidylcholine and sodium deoxycholate ratio of 85:15%, w/w. This formulation showed maximum entrapment efficiency (87.34 +/- 3.81%) and deformability index (121.5 +/- 4.21). An in-vivo study revealed that topically administered tetanus toxoid-loaded transfersomes, after secondary immunization, elicited an immune response (anti-TT-IgG) comparable with that produced by intramuscular AATT. Fluorescence microscopy revealed the penetration of transfersomes through the skin to deliver the antigen to the immunocompetent Langerhans cells.

Trapping force on a finite-sized particle in a dielectrophoretic cage

The point dipole (PD) model is routinely used for estimating the dielectrophoretic (DEP) force acting on a particle placed in the nonuniform electric fields of dielectrophoresis devices, such as square cages. We show that if the particle size is much smaller than the dielectrophoretic cage size, the PD model accurately approximates the actual DEP force, computed numerically using the Maxwell stress tensor method. However, when the two sizes are comparable, the actual DEP force differs significantly in both magnitude and direction from that given by the PD model.

Non-ionic surfactant based vesicles (niosomes) for non-invasive topical genetic immunization against hepatitis B

DNA vaccines are capable of eliciting both humoral as well as cellular immune responses. Liposomes have been widely employed for DNA delivery through topical route; however, they suffer from certain drawbacks like higher cost and instability. In present study, non-ionic surfactant based vesicles (niosomes) for topical DNA delivery have been developed. DNA encoding hepatitis B surface antigen (HBsAg) was encapsulated in niosomes. Niosomes composed of span 85 and cholesterol as constitutive lipids were prepared by reverse phase evaporation method. Prepared niosomes were characterized for their size, shape and entrapment efficiency. The immune stimulating activity was studied by measuring serum anti-HBsAg titer and cyokines level (IL-2 and IFN-gamma) following topical application of niosomes in Balb/c mice and results were compared with naked DNA and liposomes encapsulated DNA applied topically as well as naked DNA and pure recombinant HBsAg administered intramuscularly. It was observed that topical niosomes elicited a comparable serum antibody titer and endogenous cytokines levels as compared to intramuscular recombinant HBsAg and topical liposomes. The study signifies the potential of niosomes as DNA vaccine carriers for effective topical immunization. The proposed system is simple, stable and cost effective compared to liposomes.

Oesophageal foreign bodies at the University Hospital of the West Indies

A retrospective study was conducted of 97 patients with oesophageal foreign bodies (EFB). The patients were admitted to assess characteristics of EFB, modes of presentation and radiological and endoscopic findings. The patients were from the University Hospital of the West Indies and most (42%) were over the fourth decade of life. The commonest EFB were bones. A negative radiological finding was not a reliable means to select patients for endoscopy. Oesophagoscopy is a reliable method in the treatment of EFB impaction. There were no major complications or deaths.

Development of a single dose tetanus toxoid formulation based on polymeric microspheres: a comparative study of poly(d,l-lactic-co-glycolic acid) versus chitosan microspheres

Stable polymeric microspheres capable of controlled release of tetanus toxoid (TT) for periods ranging from days to over months were developed. TT was stabilized, encapsulated in microspheres prepared from poly(D,L)-lactide-co-glycolide (PLGA) and chitosan by using protein stabilizer (trehalose) and its immune response was compared. The influence of co-encapsulated protein stabilizer on tetanus toxoid's stability and release from the microspheres was studied. The protein stabilizer (trehalose) prevented structural losses and aggregation of microencapsulated TT. To neutralize the acids liberated by the biodegradable lactic/glycolic acid-based polymer, we also co-incorporated into the polymer an antacid, (Mg(OH)2), which neutralized the acidity during degradation of the polymer and also prevented TT structural losses and aggregation. The in vitro release experiments with PLGA and chitosan microspheres were performed and the release of TT was increased up to 80-90%. The antigen integrity was investigated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) followed by coomassie brilliant blue staining. The SDS-PAGE analysis confirmed that antigen integrity was not affected by the encapsulation procedure. In addition, the immunogenicity of PLGA and chitosan microspheres based single dose vaccine was evaluated in guinea pigs and compared with multiple doses of alum adsorbed TT. Results indicated that a single injection of PLGA and chitosan microspheres containing TT could maintain the antibody response at a level comparable to the booster injections of conventional alum adsorbed vaccines. The both PLGA and chitosan based stable vaccine formulations produced an equal immune response. Hence chitosan can be used to replace the expensive polymer PLGA. This approach should have potential application in the field of vaccine delivery.

Endobronchial non-Hodgkin's lymphoma

A 23-year-old male presented with clinical and radiological features of left lung collapse. Fibre-optic bronchoscopy revealed a smooth globular mass almost completely occluding the left main bronchus. Needle aspiration and endobronchial biopsy from the mass revealed it to be a case of anaplastic large cell lymphoma, a subtype of non-Hodgkin's lymphoma. This report documents the rare presentation of non-Hodgkin's lymphoma as an endobronchial mass.

Presentation and outcome of rhino-orbital-cerebral mucormycosis in patients with diabetes

AIM

To report presentation and outcome of rhino-orbital-cerebral mucormycosis (ROCM) exclusively in patients with diabetes mellitus.

METHODS

Retrospective, non-comparative, interventional analysis of the medical records of 35 patients with ROCM among 22 316 patients with diabetes seen over the last 12 years.

RESULTS

A cohort of 23 men and 12 women with a mean (SD) age of 47.3 (14.4) years (range 18-70 years) was studied. Five patients had type 1 diabetes mellitus, 29 had type 2 diabetes mellitus, and one had secondary diabetes. Nine patients had ROCM as the first clinical manifestation of diabetes. The mean (SD) blood glucose at presentation was 20.6 (8.3) mmol/l (range 10.0 to 53.3 mmol/l) and 17 patients had ketosis/ketoacidosis. Ophthalmic symptoms and signs were pronounced: external ophthalmoplegia (89%), proptosis (83%), visual loss (80%), chemosis (74%), and eye lid gangrene (14%). Non-ophthalmic manifestations included sinusitis (100%), nasal discharge/ulceration (74%), infranuclear VI nerve palsy (46%), palatal necrosis (29%), cerebral lobe involvement (20%), and hemiparesis (17%). Computed tomography/magnetic resonance imaging showed involvement of paranasal sinuses in all patients with ethmoid (86%) and maxillary (80%) sinuses being most frequently involved. Orbital involvement was observed in 80% of patients with cavernous sinus thrombosis in 11%, and internal carotid occlusion and hydrocephalus in 3% each. All were treated with amphotericin B (3-3.5 g) and 26 (74%) patients underwent appropriate surgery. Twenty one patients (68%) survived with a mean (SD) follow up of 39.6 (34.1) months (range 10 months to 11 years). Factors related to poor survival included delay in diagnosis and treatment (p<0.05), facial and/or eye lid gangrene (p<0.05), hemiplegia (p<0.05), cerebral invasion by mucorales (p<0.05), and treatment with amphotericin B alone (p<0.05).

CONCLUSIONS

In patients with diabetes and ROCM, ROCM was the presenting manifestation in one fourth of the patients. Ophthalmic and extensive cerebral involvement predominated in the clinical picture. Delay in treatment due to late presentation and associated complications were major determinants of the survival outcome in these patients.

Development of a single-dose stabilized poly(D,L-lactic-co-glycolic acid) microspheres-based vaccine against hepatitis B

The purpose of this study was to develop a stable single-dose vaccine based on recombinant hepatitis B surface antigen (HBsAg) in poly(D,L-lactic-co-glycolic acid) (PLGA) microspheres, in which HBsAg was stabilized by a protein stabilizer (trehalose) and an antacid (Mg(OH)2). The microspheres were prepared by the double emulsion method and characterized by scanning electron microscopy. To neutralize the acids liberated by the biodegradable lactic/glycolic acid based polymer, we coincorporated into the polymer an antacid, Mg(OH)2, which neutralized the acidity during degradation of the polymer and also prevented HBsAg structural losses and aggregation. The antigen integrity after encapsulation was examined by sodium dodecyl sulfate polyacrylamide gel electrophoresis followed by silver staining, isoelectric focusing and Western blotting techniques, which confirmed that antigen remained intact after encapsulation. In-vitro release experiments were performed in phosphate-buffered saline (pH 7.4) and the release of antigen was found to be improved by the protein stabilizer (trehalose). In stability studies, performed at 37 degrees C, the microspheres were found to be stable for 16 days. The immunogenicity of stable microsphere formulations bearing HBsAg was compared with the conventional alum-absorbed HBsAg vaccine in a guinea-pig model. The antibody titre indicated that a single injection of stabilized HBsAg-PLGA microspheres produced a better immune response than two injections of alum-formulated HBsAg vaccine. The findings suggest that recombinant HBsAg can be stabilized by use of a protein stabilizer and antacid during entrapment, and this stabilized preparation can be useful for antigen delivery.

Diagnosis and prognostication of adult spinal cord injury without radiographic abnormality using magnetic resonance imaging: analysis of 40 patients

BACKGROUND

Spinal cord injury without radiographic abnormality (SCIWORA) is not uncommon among middle-aged and elderly people. It is less reported in adults as compared with children. This study was undertaken to find the incidence, magnetic resonance imaging (MRI) changes, and outcome of SCIWORA in adults and to demonstrate the prognostic value of MRI in SCIWORA.

MATERIALS AND METHODS

Forty adult patients who sustained SCIWORA for a period of 2 years (January 1999 to December 2000) were admitted to our hospital. Methylprednisolone was given in therapeutic doses, for a period of 24 hours, to those arriving within 6 hours of injury. Magnetic resonance imaging was performed within 72 hours of admission to the hospital. In all patients, sagittal, axial, and coronal T1, spin, and T2 images of MRI were obtained. Clinical status of the patient at the time of admission and discharge was correlated with MRI.

RESULTS

Four patients (10%), who were in Frankel grade D, with no demonstrable injury on MRI, improved to Frankel grade E at the time of discharge. Two patients (5%) with cord edema and extraneural injury improved to a useful neurological grade (Frankel grades D or E), whereas 13 patients (32.5%) with MRI features of cord contusion and hemorrhage did not achieve useful neurological function.

CONCLUSION

Spinal cord injury without radiographic abnormality contributes 12% of cases of spinal cord injury. Magnetic resonance imaging is the investigation of choice, having diagnostic and prognostic value because it demonstrates neural and extraneural injuries and helps to pick up surgically correctable abnormality. Patients with minimal cord changes on MRI have the best outcome followed by those with cord edema. Patients with parenchymatous hemorrhage and contusion on MRI fare badly.

Common cancers in India: knowledge, attitudes and behaviours of urban slum dwellers in New Delhi

RESEARCH QUESTIONS

What is the level of knowledge and awareness of common cancers? What are the prevalent attitudes and behaviours relating to common cancers?

OBJECTIVES

To assess knowledge, attitudes and behaviours regarding common cancers amongst urban slum dwellers in New Delhi.

STUDY DESIGN

Field-based cross-sectional survey of an urban slum cluster.

SETTING

Slum clusters along Pankha Road, West New Delhi.

PARTICIPANTS

Slum dwellers of selected slums.

STUDY VARIABLES

Independent variables were sociodemographic factors. Dependent variables were knowledge, attitudes and behaviours regarding preventive and curative aspects of common cancers.

STATISTICAL ANALYSIS

Proportions, confidence intervals, tests of significance and multiple logistic regression.

RESULTS

Only 13% (10.6-15.7%) of the study participants were aware of Pap smears, and only 2% (1.1-3.3%) were able to identify all the common signs of cancer. However, 87% (84.4-89.5%) of the study participants knew that tobacco is a risk factor for cancer. Overall, 51% (47.2-54.7%) had some knowledge pertaining to cancer.

CONCLUSION

A focused, concerted and effective information, education and communication drive is urgently needed for all aspects of common cancers in India.

Modified push-pull osmotic system for simultaneous delivery of theophylline and salbutamol: development and in vitro characterization

An oral osmotic system which can deliver theophylline and salbutamol sulphate simultaneously for extended period of time was developed and characterized in a view to reduce the problems associated with the multidrug therapy of asthma. Simple controlled porosity osmotic pump contained both drugs (in freely soluble form) did not provide satisfactory extended release of theophylline. A modified two-layered, push-pull osmotic system was developed by using the basic designs of various oral osmotic pumps, such as controlled porosity osmotic pump (CPOP), elementary osmotic pump (EOP) and push-pull osmotic pump (PPOP). Scanning electron microscopy of cellulose acetate coating membrane after dissolution revealed that 25% (w/w) of sorbitol can be used as an optimized concentration of pore forming agent with 25% (w/w) of plasticizer, which was kept constant. Formulations were initially developed for theophylline and the release was optimized by using two different soluble forms of theophylline with varying amount of hydrophilic polymer mixture in upper layer and polyethylene oxide (expandable hydrogel) in lower layer. Further, the release of salbutamol sulphate was optimized by keeping the drug in upper or lower layer or both layers. In vitro release studies showed satisfactory controlled release profiles of both drugs. The release profiles of both drug statistically compared with respective marketed controlled release formulations. An optimized system was selected to study the effect of concentration of pore forming agent and orifice diameter on the release of both drugs.

Morphological description of combined variation of distal attachments of fibulares in a foot

An interesting case of peculiarity of the distal attachment of the three fibular muscles is reported in the left foot of a male adult cadaver of Indian origin. The fibularis brevis, just inferior to the fibular malleolus, gave off an additional slender tendon anteromedial to its main tendon. This was attached to the dorsal digital expansion of the little toe while its main tendon was inserted to the customary bone. The tendon of fibularis longus on the plantar aspect just medial to the cuboid tunnel received a prominent slip of attachment of the tendon of tibialis posterior. The fibularis tertius had two parallel-running tendons attached to the bases of the fourth metatarsal and the fourth and fifth metatarsals respectively. The combined variation of the three fibulares in a single foot has not been reported previously. The more distal attachment of the fibularis brevis in this case is a regression in evolution. Weakness of both the fibularis brevis and fibularis longus is found in pes cavovarus. The former can be used as a rotational graft in soft tissue loss of the leg.

Cholera toxin B subunit conjugated bile salt stabilized vesicles (bilosomes) for oral immunization

Bile salt stabilized vesicles, bilosomes appear to be a promising and potential carrier system for oral delivery of peptides and proteins. Bilosomes containing bovine serum albumin (BSA), a model antigen, were prepared and conjugated with cholera toxin B subunit (CTB) in order to enhance their affinity towards M cells of Peyer's patches. Stability studies were undertaken to ascertain the effect of simulated gastric fluid (SGF, pH 1.2), simulated intestinal fluid (SIF, pH 7.5) and different concentrations of bile salts. Intactness and biological activity of CTB were checked by hemagglutination test. A single oral dose of CTB-conjugated bilosomes produced almost equivalent response compared to parenteral administration of antigen with Freund's complete adjuvant (FCA). However, in contrast to FCA, oral administration of bilosomes is convenient and devoid of any adverse effects that are observed with parenteral administration of FCA. Serum IgG titers after single administration were significantly better (P < 0.05) than oral administration of antigen with other systems for 3 consecutive days, suggesting an effective stimulation of systemic immune response. Mucosal IgA titers obtained advocated a possible application of CTB-conjugated bilosomes as oral vaccine delivery system.

Factors influencing refusal by relatives of brain-dead patients to give consent for organ donation: experience at a transplant centre

To analyse the reasons for family refusal for donating the organs of their deceased relatives, 33 families were approached and interviewed as a part of the consent process. Thirty of these refused and their reasons for refusal were documented. In 83%, the principle reason for refusal to give consent was the non-acceptance of brain death. Superstitions relating to being reborn with a missing organ (that had been donated) in 40% or that tampering with the body would not free their dead relatives from the cycle of life-death-rebirth in 26% were next most frequently voiced. A delay in funeral (23%), lack of consensus within family members (17%), fear of social criticism (10%), dissatisfaction with the hospital staff (10%) and being unaware of their deceased relatives' wishes (6%) were the other reasons cited.

Total number and mean size of alveoli in mammalian lung estimated using fractionator sampling and unbiased estimates of the Euler characteristic of alveolar openings

Estimation of alveolar number in the lung has traditionally been done by assuming a geometric shape and counting alveolar profiles in single, independent sections. In this study, we used the unbiased disector principle to estimate the Euler characteristic (and thereby the number) of alveolar openings in rat lungs and rhesus monkey lung lobes and to obtain robust estimates of average alveolar volume. The estimator of total alveolar number was based on systematic, uniformly random sampling using the fractionator sampling design. The number of alveoli in the rat lung ranged from 17.3 x 10(6) to 24.6 x 10(6), with a mean of 20.1 x 10(6). The average number of alveoli in the two left lung lobes in the monkey ranged from 48.8 x 10(6) to 67.1 x 10(6) with a mean of 57.7 x 10(6). The coefficient of error due to stereological sampling was of the order of 0.06 in both rats and monkeys and the biological variation (coefficient of variance between individuals) was 0.15 in rat and 0.13 in monkey (left lobe, only). Between subdivisions (left/right in rat and cranial/caudal in monkey) there was an increase in variation, most markedly in the rat. With age (2-13 years) the alveolar volume increased 3-fold (as did parenchymal volume) in monkeys, but the alveolar number was unchanged. This study illustrates that use of the Euler characteristic and fractionator sampling is a robust and efficient, unbiased principle for the estimation of total alveolar number in the lung or in well-defined parts of it.

Inclusive double-pomeron exchange at the fermilab tevatron p p collider

We report results from a study of events with a double-Pomeron exchange topology produced in p p collisions at sqrt[s]=1800 GeV. The events are characterized by a leading antiproton and a large rapidity gap on the outgoing proton side. We find that the differential production cross section agrees in shape with predictions based on Regge theory and factorization, and that the ratio of double-Pomeron exchange to single diffractive production rates is relatively unsuppressed as compared to the O(10) suppression factor previously measured in single diffractive production.