Chitosan composites for bone tissue engineering--an overview

Bone contains considerable amounts of minerals and proteins. Hydroxyapatite [Ca₁₀(PO₄)₆(OH)₂] is one of the most stable forms of calcium phosphate and it occurs in bones as major component (60 to 65%), along with other materials including collagen, chondroitin sulfate, keratin sulfate and lipids. In recent years, significant progress has been made in organ transplantation, surgical reconstruction and the use of artificial protheses to treat the loss or failure of an organ or bone tissue. Chitosan has played a major role in bone tissue engineering over the last two decades, being a natural polymer obtained from chitin, which forms a major component of crustacean exoskeleton. In recent years, considerable attention has been given to chitosan composite materials and their applications in the field of bone tissue engineering due to its minimal foreign body reactions, an intrinsic antibacterial nature, biocompatibility, biodegradability, and the ability to be molded into various geometries and forms such as porous structures, suitable for cell ingrowth and osteoconduction. The composite of chitosan including hydroxyapatite is very popular because of the biodegradability and biocompatibility in nature. Recently, grafted chitosan natural polymer with carbon nanotubes has been incorporated to increase the mechanical strength of these composites. Chitosan composites are thus emerging as potential materials for artificial bone and bone regeneration in tissue engineering. Herein, the preparation, mechanical properties, chemical interactions and in vitro activity of chitosan composites for bone tissue engineering will be discussed.     

Pharmacokinetics and distribution of sulphadimidine in plasma,milk and uterine fluid of female buffaloes

The pharmacokinetics of sulphadimidine after a single dose (200 mg/kg i.v.) was studied in five healthy lactating buffaloes. The study revealed that the drug attained its peak concentration of 314.0±13.0, 242.4±3.0 and 100.2±2.5 g/ml at 15 min, 30 min and 12 h in plasma, milk and uterine fluid, respectively. The pharmacokinetic parameters calculated by a 2-compartment open model gave values for t₁, t₁ and vd_area of 2.10±0.36 h, 12.36±0.57 h and 1.23±0.07 L/Kg, respectively. A high vd_area as well as a value of 0.74±0.08 for K₁₂:K₂₁- (tissue Plasma) indicates better penetration of the drug into the different body fluids and tissues, which is further supported by a high concentration obtained in milk and uterine fluid. The therapeutic concentration (50 g/ml) was maintained for around 24 h in plasma and milk and 12 h in uterine fluid. The results suggest that, apart from its use in systemic infections, the drug can be effectively used by the i.v. route in uterine and mammary gland infections. The dosages for maintaining concentration of 50 g/ml, 100 g/ml and 150 g/ml at convenient dosage intervals of 12 and 24 h were also determined.     

Differentiation of peste des petits ruminants and rinderpest viruses by neutralisation indices using hyperimmune rinderpest antiserum

Summary Six field isolates believed to be rinderpest viruses and 2 known strains of peste des petits ruminants (PPR) viruses were titrated in the presence of normal rabbit serum and with hyperimmune rinderpest antiserum prepared in rabbits. The known PPR viruses had indices less than 10 whereas 4 of the suspect field isolates had indices greater than a hundred. Two suspect field isolates had indices less than 20; both were collected from small ruminant wild life and are probably PPR viruses.

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Diferenciacion De Peste De Los Pequenos Rumiantes Y Virus De Rinderpest Mediante Indices De Neutrilizacion Utilizando Antisueros Hiperinmunes De Rinderpest

Resumen Seis aislamientos de campo sospediosos de Rinderpest y dos cepas conocidas de Peste de los pequeños rumiantes (PPR) fueron titulados en titulados en presencia de suero normal de conejo y suero hiperimmune a Rinderpest, prepardo en conjo. Las cepas concidos de PPR dierond titulos menores de 10, mientras que 4 de los aislamientos sospechosos de Rinderpest dieron titulos mayores de 100. Los 2 aislamientos de campo restantes dieron titulos menores de 20. Ambos fueron aislados de pequenños ruminantes silvestras y probablemente sean virus de PPR.

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Differenciation Des Virus De La Peste Bovine Et De La Peste Des Petits Ruminants Par Les Indices De Neutralisation Utilisant Des Antiserums Hyperimmuns De La Peste Bovine

Résumé La titration de 6 isolats recuellis sur le terrain et considérés comme étant du virus de la peste bovine, et 2 souches connues du virus de la peste des petits ruminants (PPR) ont été titrés en présence de sérum normal de lapin et avec un antisérum hyperimmun de la peste bovine préparé sur lapins. Les virus identifiés PPR avaient des indices inférieurs à 10 alors que 4 des isolats suspects présentaient des indices supérieurs à 100. Deux isolats suspects avaient des indices inférieurs à 20 et tous deux provenaient de petits ruminants sauvages et sont probablement des virus de la PPR.

     

Effect of lameness (hoof disorders) on productivity of Karan Fries crossbred cows

In present study production performance of 96 lame cows was compared with 67 healthy cows. No significant effect of parity and year of calving on milk yield were observed but the effect of season of calving was significant (P < 0.01). Effect of lameness on milk yield at the second, third and fourth months and 305 days was highly significant (P < 0.01), and was also significant (P < 0.05) on lactation yield of the fifth and tenth months. The effect of lameness on monthly and 305‐day milk yield was significant (P < 0.01) only for those cows diagnosed lame before calving and during the first month of lactation. The differences in mean monthly yield were highly significant (P < 0.01) at the second, third and fourth months; and significant (P < 0.05) in the first and fifth months. The loss in the first lactation month of cows which were diagnosed as lame in the second month, was found to be significant (P < 0.05). Thus the yield of the month previous to the diagnosis (sub‐clinical stage) was also affected. A significant (P < 0.01) total loss of 498.95 kg of milk yield was observed during a period of 305 days.     

Zoonotic cases of camelpox infection in India

This study reports the first conclusive evidence of zoonotic camelpox virus (CMLV) infection in humans associated with outbreaks in dromedarian camels (Camelus dromedaries) in northwest region of India during 2009. CMLV infection is usually restricted to camels and causes localised skin lesions but occasionally leads to generalised form of disease. However, the present outbreak involved camel handlers and attendants with clinical manifestations such as papules, vesicles, ulceration and finally scabs over fingers and hands. In camels, the pock-like lesions were distributed over the hairless parts of the body. On the basis of clinical and epidemiological features coupled with serological tests and molecular characterization of the causative agent, CMLV zoonosis was confirmed in three human cases. Clinical samples such as skin scabs/swabs and blood collected from affected animals and humans were analysed initially, for the presence of CMLV-specific antigen and antibodies by counter immunoelectrophoresis (CIE); serum neutralization test (SNT); plaque-reduction neutralization test (PRNT) and indirect immunoperoxidase test which was later confirmed by amplification of CMLV-specific ankyrin repeat protein (C18L) gene. Virus isolation was successful only from samples collected from camels. Further, sequence analyses based on three full-length envelope protein genes (A27L, H3L and D8L) revealed 95.2-99.8% and 93.1-99.3% homology with other Orthopoxviruses at nucleotide and amino acid levels, respectively. Phylogram of the three genes revealed a close relationship of CMLV with Variola virus (VARV). Considering the emerging and re-emerging nature of the virus, its genetic relatedness to VARV, zoonotic potential and productivity losses in camels; the control measures are imperative in curtailing economic and public health impact of the disease. This is the first instance of laboratory confirmed camelpox zoonosis in India.     

Anatomy of the vertebral column,ribs and sternum in orange rumped agouti (Dasyprocta leporina Linnaeus, 1758): Structural and Functional perspectives

The axial skeleton of orange rumped agouti, Dasyprocta leporina, was studied for better understanding of its locomotor behaviour. The bones from eight adult agoutis of both sexes were observed for their anatomical features and functional significance. The vertebral formula was found to be C₇T₁₂L₇S₅Cy_5–6. The well-developed occipital crest, caudally oriented prominent axis spine and well-developed transverse processes from C₃–C₇ indicated a highly flexible neck with greater sagittal mobility. Articular facets were horizontal in anterior series while oblique in the posterior series, which enabled them to perform both lateral and sagittal movements during locomotion. The caudally directed thoracic spines, T₁₂ as anticlinal vertebra and prominent mamillary process in the posterior series were suggestive of strong dorso-ventral flexion/extension and rotation. The robust lumbar vertebrae, well-developed transverse processes with cranio-ventral extension, were the feature for powerful sagittal/dorsoventral movement. The presence of spinous processes and well-developed transverse processes in all caudal vertebrae was an indication of a highly movable tail. The ribs were 13 pairs with first seven as sternal and six as asternal. They were laterally compressed in the anterior series as a cursorial adaptation. A strong muscular attachment to vertebrae provides this rodent speed, agility, dexterity and strength suitable for survival in food chain.     

Rapid detection of Mycobacterium bovis on its lipid profile by thin layer chromatography

Sixteen Mycobacterium bovis (M. bovis) strains isolated from bovine tissues and one standard reference strain of M. bovis AN5 alongwith other species of mycobacteria for comparison were investigated for the presence of phenolic glycolipid (PGL) and phthiocerol dimycocerosate (PDIM) for rapid identification of M. bovis by thin-layer chromatography (TLC). The study indicated presence of PGL with an Rf value of 0.75 in chloroform-methanol solvent in all 17 M. bovis strains. The dimycocerostate A corresponding to spot A was the major constituent among all the three spots in M. bovis strains. TLC appeared to be a promising alternative to conventional biochemical methods for identification of M. bovis taking into consideration both PGL and PDIM lipids.     

Isolation and characterization of Indian isolates of camel pox virus

In this study, we isolated and identified three camel pox viruses (CMLV) from two outbreaks of camel pox infection in camels associated with eruptions on cheeks, nostrils, limbs, scrotum, and sheath that occurred at different places of Bikaner district, Rajasthan (India). The scab specimens collected were subjected for virus isolation in Vero cell culture, and the isolated viruses were characterized by employing polymerase chain reaction (PCR) and sequencing. The causative agent was identified as CMLV, based on A-type inclusion, B5R and C18L genes-specific PCRs and partial sequencing of these genes, which clearly confirmed that the outbreaks were caused by CMLV and identity of CMLV isolates. Further, phylogenetic analysis of partial C18L gene sequences have showed that Indian CMLV are clustered together with other reported isolates/strains.