Novel in Vitro Efficiency of Chitosan Biomolecule against Trichomonas gallinae

Background

Development of new natural agents for parasitic diseases treatment has unexpectedly increased to overcome effectively against emergence and re-emergence of parasitic diseases, the appearance of drug resistant organisms and toxic side effects of current agents. The aim of the study was to evaluate antiprotozoal activities of chitosan biomolecule on trophozoites of Trichomonas gallinae.

Methods

The antitrichomonal activity of various low molecular weight chitosan concentrations including 125, 250, 500 and 1250 µg ml⁻¹ against T. gallinae trophozoites cultured in trypticase-yeast extract-maltose medium supplemented with heat-inactivated cold horse serum was evaluated in vitro. Samples containing medium without chitosan were also assayed as controls.

Results

The mortality rates at 0, 3 and 6 h post treatment with all concentrations were significantly different from control group (P<0.05). Treated trophozoites showed more susceptibility to the highest concentration reaching mortality rate of 100% at 3h post inoculation. However, at this time, results for 125, 250 and 500 µg ml⁻¹ were 93%, 95% and 96.7%, respectively.

Conclusion

The results demonstrate that the application of chitosan biomolecule is a promising option for treatment of trichomoniasis in pigeons.     

Cryptosporidium Spp. Infection in Human and Domestic Animals

Background

Cryptosporidium spp. is a coccidian parasite infected humans and animals. Prevalence rate of Cryptosporidium spp. infection associated with is some parameters such as sampling, age, season, country and contact to domestic animals. This study aimed to determine Cryptosporidium spp. Infection in humans and some animals in rural areas of Shushtar district from Khuzestan Province, south- west of Iran.

Methods

In this study, Stool specimens were randomly collected from 45 cattle, 8 buffalos, 35 calves, 22 turkeys, 3 sheep, 2 geese as well as 62 humans in different seasons selected from rural areas of Shushtar district located in Khuzestan in the south- west of Iran from August 2009 to April 2011. The collected stool samples were examined by modified Ziehl-Neelsen staining method.

Results

Altogether, 68/115 (59.1%) domestic animals and 9/62 (14.5%) of humans were showed Cryptosporidium spp. infection in the study areas.

Conclusion

In this study we found the high frequency of Cryptosporidium spp. infection in the studied areas.     

Positive end-expiratory airway pressure does not aggravate ventilator-induced diaphragmatic dysfunction in rabbits

Introduction

Immobilization of hindlimb muscles in a shortened position results in an accelerated rate of inactivity-induced muscle atrophy and contractile dysfunction. Similarly, prolonged controlled mechanical ventilation (CMV) results in diaphragm inactivity and induces diaphragm muscle atrophy and contractile dysfunction. Further, the application of positive end-expiratory airway pressure (PEEP) during mechanical ventilation would result in shortened diaphragm muscle fibers throughout the respiratory cycle. Therefore, we tested the hypothesis that, compared to CMV without PEEP, the combination of PEEP and CMV would accelerate CMV-induced diaphragm muscle atrophy and contractile dysfunction. To test this hypothesis, we combined PEEP with CMV or with assist-control mechanical ventilation (AMV) and determined the effects on diaphragm muscle atrophy and contractile properties.

Methods

The PEEP level (8 cmH₂O) that did not induce lung overdistension or compromise circulation was determined. In vivo segmental length changes of diaphragm muscle fiber were then measured using sonomicrometry. Sedated rabbits were randomized into seven groups: surgical controls and those receiving CMV, AMV or continuous positive airway pressure (CPAP) with or without PEEP for 2 days. We measured in vitro diaphragmatic force, diaphragm muscle morphometry, myosin heavy-chain (MyHC) protein isoforms, caspase 3, insulin-like growth factor 1 (IGF-1), muscle atrophy F-box (MAFbx) and muscle ring finger protein 1 (MuRF1) mRNA.

Results

PEEP shortened end-expiratory diaphragm muscle length by 15%, 14% and 12% with CMV, AMV and CPAP, respectively. Combined PEEP and CMV reduced tidal excursion of segmental diaphragm muscle length; consequently, tidal volume (VT) decreased. VT was maintained with combined PEEP and AMV. CMV alone decreased maximum tetanic force (Po) production by 35% versus control (P < 0.01). Combined PEEP and CMV did not decrease Po further. Po was preserved with AMV, with or without PEEP. Diaphragm muscle atrophy did not occur in any fiber types. Diaphragm MyHC shifted to the fast isoform in the combined PEEP and CMV group. In both the CMV and combined PEEP and CMV groups compared to controls, IGF-1 mRNAs were suppressed, whereas Caspase-3, MAFbx and MuRF1 mRNA expression were elevated.

Conclusions

Two days of diaphragm muscle fiber shortening with PEEP did not exacerbate CMV-induced diaphragm muscle dysfunction.     

G蛋白偶联受体激酶的研究进展

G蛋白偶联受体激酶(GRKs)属丝氨酸／酪氨酸蛋白激酶家族,其亚型广泛存在于各种组织, 能特异地使活化的G蛋白偶联受体(GPCR)发生磷酸化及脱敏化,从而终止后者介导的信号转导通路．现就G蛋白偶联受体激酶的结构、种类及分布、生物学功能及与疾病关系的新进展进行总结与概括,并对其发展进行了展望．     

The effect of chemotherapy on the kinetics and proliferative capacity of normal and tumorous tissues in vivo

The proliferative state of a given tissue is a major determinant of its sensitivity to both phase-specific and cycle-specific chemotherapeutic agents. To study the extent of injury induced by antitumor agents to normal and tumorous tissues, a technique for following DNA synthesis as reflected in the incorporation of tritiated thymidine (3H-TdR) into DNA was compared to the conventional radioautographic technique of the labeling index (LI) and to the functional kinetic technique of granulocyte colony formation in vitro. Alterations in DNA synthesis induced by a single dose of cyclophosphamide in normal and tumorous tissues in vivo paralleled in many respects the changes seen when the more time-consuming techniques of the LI or granulocyte colony formation were employed. However, the recovery of granulocyte colony formation after cyclophosphamide therapy lagged behind the recovery of DNA synthesis in the bone marrow, obscuring a kinetic event of potential therapeutic significance. The determination of DNA synthesis simultaneously in normal and tumorous tissues in vivo was easy to perform and supplied therapeutically pertinent results comparatively quickly.     

A clonally distinct recurrence of Burkitt's lymphoma at 15 years

A human immunodeficiency virus-negative male was successfully treated for two occurrences of Burkitt's lymphoma, 15 years apart. As consolidation of his second remission, he underwent high-dose chemotherapy with peripheral blood stem cell transplantation. In an effort to prove whether the second lymphoma was a relapse of the first or a second primary lymphoma, we obtained paraffin-embedded material from both lymphomas. DNA was extracted from this material and amplified by polymerase chain reaction (PCR) using consensus JH and VH region primers. Analysis of the PCR products, which mostly reflects VDJ joints, showed two sharp bands of different molecular size, proving the monoclonal nature of the lymphomas and suggesting that each had different Ig gene rearrangements. Sequencing of both PCR products showed a marked dissimilarity in nucleotide sequence in the clonally unique VDJ joint region, providing strong evidence for the separate cellular genesis of each lymphoma. These results suggest that late relapses of Burkitt's lymphoma should be examined for clonal distinctiveness. If the second lymphoma is distinct from the primary one, it might be treated as a primary lymphoma rather than as recurrent disease.