Nicotine-induced purposeless chewing in rats: possible dopamine receptor mediation

Intraperitoneal (i.p.) administration of nicotine to rats induced purposeless chewing. The response induced by different doses of the drug (0.0001, 0.001, 0.01 and 0.1 mg/kg) seems to be dose dependent, with a maximum effect at 0.01 mg/kg and then decreasing at a higher dose (0.1 mg/kg). Pre-treatment of animals with the nicotine antagonist mecamylamine (0.01 and 0.1 mg/kg, 30 min) and the D-2 receptor antagonist sulpiride (12.5-100 mg/kg, 90 min), but not the D-1 antagonist SCH 23390 (0.01 and 0.05 mg/kg, 30 min), decreased the chewing induced by nicotine (0.01 mg/kg). When animals were pre-treated with propranolol (5 and 10 mg/kg) 60 min, reserpine (2.5 mg/kg) 18 h or α-methyl-p-tyrosine (α-MPT; 250 mg/kg) 60 min before nicotine, the effect of the drug was reduced. However, reserpine (2.5 mg/kg) at 18 h plus α-MPT (250 mg/kg) 60 min prior to nicotine completely inhibited the drug response. Pre-treatment of animals with phenoxybenzamine (2.5 and 5 mg/kg i.p., 60 min) or atropine (5 and 10 mg/kg) did not change the nicotine response significantly. It is concluded that nicotine- induced purposeless chewing is mediated through dopaminergic and nicotinic mechanisms.     

Inhibition of Staphylococcus Aureus Mediated by Extracts from Iranian Plants

In order to find new antibacterial agents effective against Staphylococcus aureus, ethanolic extracts of 10 plants were tested. S. aureus (489 samples) were isolated either from healthy carriers (nose and throat) or clinical samples. Out of 489 isolates tested, 98.6% were sensitive to trimethoprim-sulfamethoxazole which was used as the reference antibiotic. From the plant extracts screened for antibacterial activity, Myrtus communis L. (leaves) had the greatest activity, inhibiting the growth of 99% of the isolates. Glycyrrhiza glabra L., Eucalyptus globolus Labill and Menta viridis L., were also active against the isolates inhibiting the growth of 90, 59.5 and 48.7% of the isolates, respectively. All of these extracts were active against the reference strains of S. aureus tested. Saturia hortensis L., Teucrium polium L., and Achillea santolina L., had very little antibacterial activity, while Trigonella foenum graecum L., Echium amoenum Fisch & Mey (flowers) and Juglans regia L. (leaves), had no antibacterial activity against the bacterial isolates.     

Effect of dopamine infusion on thyroid hormone tests and prolactin levels in very low birth weight infants

Objective: To evaluate the effect of dopamine on thyroid hormone tests and prolactin (PRL) and to assess requirement for L-thyroxin (LT4).

Methods: The infants (n?=?102) were divided into three groups (Group 1; received no dopamine, Group 2 received ≤25?mg/kg cumulative dose and Group 3; received >25?mg/kg cumulative dose). Blood samples were taken at 6–8 days (timepoint 1), 13–15 days (timepoint 2), and 4–6 weeks of life (timepoint 3).

Results: Respiratory distress syndrome was higher in group 2 and 3. Patnet ductus arteriosus was higher in group 3 than in groups 1 and 2. Duration and cumulative dose in group 3 were higher than group 2. There was no difference between thyroid hormones that were taken after stopping infusion at timepoint 3 among all groups. No therapy with LT4 was needed. PRL levels were higher at timepoint 1 in group 1 than compared to group 2 and 3 (p?p?>?0.05). This difference was disappeared at following timepoints.

Conclusions: The release of TSH, FT3, FT4 and PRL were not inhibited and prophylactic thyroid hormone treatment was not required in VLBW infants receiving dopamine infusions.     

Intrauterine upper extremity thrombosis successfully treated with recombinant tissue plasminogen activator, enoxaparin and collagenase

Intrauterine ischemia of the limbs is a rare condition involving thrombosis and ischemia of the extremities before birth. The clinical presentation depends on the extremity affected as well as the timing of thrombosis. Very few cases with extremity hypoperfusion and gangrene due to intrauterine thrombosis have been reported in the literature, and therefore there is no consensus on the optimal therapeutic strategy for such cases. Presented here is a case of a newborn with intrauterine brachial arterial thrombosis of the right upper extremity who was successfully treated by a combination of recombinant tissue plasminogen activator, enoxaparin and collagenase application followed by surgery.     

Beneficial Effect of Etanercept on Hyperoxic Lung Injury Model in Neonatal Rats

Purpose: To determine whether prophylaxis with etanercept, an anti-inflammatory drug, would decrease the severity of lung injury in a neonatal rat model of bronchopulmonary dysplasia (BPD); Materials and Methods: Rat pups were divided into three groups: pups exposed to room air (group 1; n = 10), to hyperoxia + placebo (group 2; n = 9), and to hyperoxia + etanercept (group 3; n = 8). Lung morphology was assessed by alveolar surface area percentage, which is a measure of alveolar size. The severities of lung inflammation and antioxidant capacity were assessed by quantifying tumor necrosis factor-α (TNF-α), transforming growth factor-β (TGF-β), malondialdehyde (MDA), and superoxide dismutase (SOD) from lung homogenate; Results: The percentage of alveolar surface areas were significantly higher in group 3 compared to group 2 (p = .004) and similar in both group 1 and group 3 (p = .21). The mean level of lung MDA was significantly higher in group 2 compared to group 1 and group 3 (p < .05 for both). Lung homogenate SOD activities in group 3 was significantly higher than group 2 (p < .001). Furthermore, group 3 pups had lower levels of TNF-α and TGF-β in lung homogenate than that in group 2 (p < .05 for both) but similar in both group 1 and group 3; Conclusion: Etanercept has favorable effects on alveolarization as well as inflammation and oxidative stress markers in a neonatal rat model of BPD.     

Laser biostimulation of wound healing: bioimpedance measurements support histology

Laser biostimulation in medicine has become widespread supporting the idea of therapeutic effects of photobiomodulation in biological tissues. The aim of this study was to investigate the biostimulation effect of laser irradiation on healing of cutaneous skin wounds, in vivo, by means of bioimpedance measurements and histological examinations. Cutaneous skin wounds on rats were subjected to 635 nm diode laser irradiations at two energy densities of 1 and 3 J/cm² separately. Changes in the electrical properties of the wound sites were examined with multi-frequency electrical impedance measurements performed on the 3rd, 7th, 10th, and 14th days following the wounding. Tissue samples were both morphologically and histologically examined to determine the relationship between electrical properties and structure of tissues during healing. Laser irradiations of both energy densities stimulated the wound healing process. In particular, laser irradiation of lower energy density had more evidence especially for the first days of healing process. On the 7th day of healing, 3 J/cm² laser-irradiated tissues had significantly smaller wound areas compared to non-irradiated wounds (p?<?0.05). The electrical impedance results supported the idea of laser biostimulation on healing of cutaneous skin wounds. Thus, bioimpedance measurements may be considered as a non-invasive supplementary method for following the healing process of laser-irradiated tissues.