Bactericidal fully human single-chain fragment variable antibodies protect mice against methicillin-resistant Staphylococcus aureus bacteraemia

OBJECTIVES

The increasing prevalence of antibiotic-resistant Staphylococcus aureus, besides the inadequate numbers of effective antibiotics, emphasises the need to find new therapeutic agents against this lethal pathogen.

METHODS

In this study, to obtain antibody fragments against S. aureus, a human single-chain fragment variable (scFv) library was enriched against living methicillin-resistant S. aureus (MRSA) cells, grown in three different conditions, that is human peripheral blood mononuclear cells with plasma, whole blood and biofilm. The antibacterial activity of scFvs was evaluated by the growth inhibition assay in vitro. Furthermore, the therapeutic efficacy of anti-S. aureus scFvs was appraised in a mouse model of bacteraemia.

RESULTS

Three scFv antibodies, that is MEH63, MEH158 and MEH183, with unique sequences, were found, which exhibited significant binding to S. aureus and reduced the viability of S. aureus in in vitro inhibition assays. Based on the results, MEH63, MEH158 and MEH183, in addition to their combination, could prolong the survival rate, reduce the bacterial burden in the blood and prevent inflammation and tissue destruction in the kidneys and spleen of mice with MRSA bacteraemia compared with the vehicle group (treated with normal saline).

CONCLUSION

The combination therapy with anti-S. aureus scFvs and conventional antibiotics might shed light on the treatment of patients with S. aureus infections.

Analgesic Effect of Valerian Root and Turnip Extracts

BACKGROUND

Medicinal plants are considered as one of the important sources of chemical substances with therapeutic effects. This study aimed to compare the analgesic effects of alcoholic extract of valerian root and turnip in rats.

METHODS

Fifty female Wistar rats weighing 190 g were divided into 5 equal groups of control (subcutaneous injection of 2.5% formalin in the right foot), sham (subcutaneous injection of 2.5% formalin+distilled water), experimental 1 (subcutaneous injection of 2.5% formalin+200 mg/kg turnip extract), experimental 2 (subcutaneous injection of 2.5% formalin 2+200 mg/kg valerian root extract) and experimental 3 (subcutaneous injection of 2.5% formalin+200 mg/kg turnip extract+200 mg/kg valerian root extract). The time duration of 0-5 and 16-60 minutes after injection of formalin were respectively considered as acute and chronic phases. Injection of distilled water and the extracts was conducted 30 minutes before assessing the analgesic effects.

RESULTS

A significant decrease in pain score in the acute phase was observed in the group received valerian root extract compared to the control group. Also, a significant reduction in pain score was noted in the acute and chronic phases of the group receiving simultaneous administration of valerian root and turnip extracts when compared to the control group.

CONCLUSION

Simultaneous use of valerian root and turnip extracts is recommended for analgesic effects in both acute and chronic phases of the pain.

Histomorphometrical changes of oviduct during the long-term exposure of breeder hens to extra thyroxine

In this research a 100 day long treatment period was considered to unmask the probable adverse effects of long-term induced hyperthyroidism on histomorphometrical attributes of the oviduct in broiler breeder hens. A total of seventy 47-week-old Cobb 500 breeder hens were randomly allotted to two treatment groups (5 replicates of 7 hens each). Thyroxine (T4) was orally administered to the hyperthyroid group (0.3 mg/bird/d) for 100 consecutive days; whereas the control group received drinking water only throughout the trial. At 64 weeks of age, 2 birds per replicate were killed by cervical dislocation and their oviducts were removed. For histomorphometrical observations, segments were taken from five different regions. After tissue preparation and staining with haematoxylin and eosin, histological layers were evaluated using light microscopy. The assessment of histomorphometrical characteristics of oviduct showed the height of mucosal folds in the magnum, thickness of mucosal folds of the magnum and uterus, thickness of tunica muscularis in the magnum and vagina, epithelial thickness of the isthmus and vagina, and uterine tubular glands percentage were decreased in the hyperthyroid birds compared with the control counterparts. The results showed long-term induced hyperthyroidism was associated with a decrease in a number of histomorphometrical traits in different regions of the oviduct. Some studies should be done to clarify to what extent the long-term maternal hyperthyroidism might affect the egg production, fertility rate, duration of fertility, and sperm penetration rate to make a final decision on exploitation of this preventative treatment to diminish the ascites incidence in progeny chicks.

Third eyelid in the small Indian mongoose (Herpestes javanicus): a morphological and histological study

The Indian mongoose (Herpestes javanicus) is native to parts of Asia, Iran. The purpose of this study was to describe the gross anatomy of the cartilage and histology of the superficial gland of the third eyelid of two adult mongooses. The animals, in terminal stages of disease and near death due to aging or unknown reasons, were referred from Park Zoo (Shiraz, Iran) to our center. By using a modified maceration technique, the morphological characteristics of the cartilage were examined. For histological examinations of the superficial gland of the third eyelid, the samples were stained with haematoxylin and eosin. Also, to detect the elastic fibers in the cartilage sections were stained with orcein and Weigert's resorcin-fuchsin. The cartilage consisted of an ovoid appendix and a mild reverse sigmoid crossbar. Elastic fibers were scattered throughout the cartilage but were more concentrated in the center. The superficial gland of the third eyelid was compound tubuloacinar with serous acini.

A detailed systematic anatomical study of monocephalic conjoined symmetric twin lambs

A case of conjoined twins with monocephalus, thoracopagus, partial abdominopagus, tetrabrachius and tetrascelus in lambs complicated with several defects of skeletal, cardiovascular, gastrointestinal, and urogenital systems is reported. The twins were dead and delivered by cesarean section. This case report highlights the detailed anatomical study of defects in different systems due to an abnormal birth defect.

A detailed systematic anatomical study of monocephalic conjoined symmetric twin lambs

A case of conjoined twins with monocephalus, thoracopagus, partial abdominopagus, tetrabrachius and tetrascelus in lambs complicated with several defects of skeletal, cardiovascular, gastrointestinal, and urogenital systems is reported. The twins were dead and delivered by cesarean section. This case report highlights the detailed anatomical study of defects in different systems due to an abnormal birth defect.

Alterations of the ovarian histomorphometry at pre-puberty in rat offspring from diabetic mothers

Purpose

Maternal diabetes leads to increased blood glucose concentration in the mother and consequently in the foetus, causing various neonatal problems. This study was conducted to evaluate the effects of maternal diabetes on foetal ovarian structure.

Methods

Sixteen adult female rats were allocated into two equal groups. Diabetes was induced in one group by alloxan. Both groups became pregnant by natural mating. Thirty days after birth, the female offspring were terminated, the body weight and blood glucose of the animals measured and their ovaries removed. Various histological and cellular parameters were determined using histological and electron microscopy techniques.

Results

Results revealed a significant increase in body weight and blood glucose in the offspring of the diabetic mothers (ODM) compared to that of the controls. The weight, volume and diameter of the ovary and the ovarian capsule thickness were inclined to decrease in ODM compared to that of controls. The number and diameter of primary, pre-antral and antral follicles were decreased in ovaries in the ODM. The electro-micrographs have demonstrated the organelle alterations in oocytes and granulosa cells that suggest the apoptosis progress and oxidative stress.

Conclusions

Maternal hyperglycaemia exhibited deleterious effects on the female reproductive system in the offspring.