Adenosine modulates synaptic plasticity in hippocampal slices from aged rats

Adenosine is known to modulate synaptic plasticity in the hippocampus of young animals through activation of adenosine A1 receptors. The objective of the present study is to investigate whether the modulatory role of adenosine on phenomena of synaptic plasticity is maintained or modified in the hippocampus of aged animals. We compared the effects of the selective adenosine A1 receptor antagonist, 1,3-dipropyl-8-cyclopentylxanthine (DPCPX, 50 nM), on paired-pulse facilitation (PPF), long-term depression (LTD), long-term potentiation (LTP) and depotentiation elicited in hippocampal slices taken from young adult (5-6 weeks) and old (2 years old) male Wistar rats. DPCPX attenuated PPF both in young (1.64 +/- 0.05 vs. 1.76 +/- 0.05%, n = 6) and in old rats (1.33 +/- 0.05 vs. 1.55 +/- 0.1%, n = 6). LTD was only observed in the presence of DPCPX in both young (21.3 +/- 0.6%, n = 4) and old rats (14.4 +/- 0.9%, n = 6). LTP induced by high-frequency stimulation (HFS) was not significantly different in young and old animals, in the presence or in the absence of DPCPX. A larger depotentiation was observed in the presence of DPCPX in young rats (27.6 +/- 4.4% vs. 16.8 +/- 4.7%, n = 7) as well as in old rats (41.3 +/- 5.1% vs. 16.1 +/- 2.7%, n = 6). LTP induced by theta-burst stimulation was observed only in the presence of DPCPX (53.9 +/- 4.9%, n = 5) in young rats, but could be obtained either in the control solution (81.8 +/- 17.9%, n = 7) or in the presence of DPCPX (98.5 +/- 24.2%, n = 7) in old rats. The modulatory role of endogenous adenosine on synaptic plasticity is generally maintained in aged animals. Drugs interfering with adenosine A1 receptor effects could then be used in old animals to modify synaptic plasticity with relevant behavioural consequences.     

Serum cholesterol and impulsivity in personality disorders

Decreased serum cholesterol has been associated with impulsive aggressive behaviors. This study was designed to explore the relationship between serum cholesterol levels and measures of impulsive aggression in personality disordered patients. Forty-two personality disordered patients (14 borderline personality disorder, 28 other personality disorders) were included. Fasting serum cholesterol was measured by standard enzymatic assay. An ANOVA was performed with factors of gender and diagnosis, looking at two-way interactions between the factors and serum cholesterol. Patients with borderline personality disorder were found to have significantly lower serum cholesterol than non-borderline personality disorders. A significant interaction effect was also seen between gender and diagnosis with the male patients having lower cholesterol levels. This study suggests there may be a relationship between borderline personality disorder and low serum cholesterol.     

The effect of onlay Medpor implants on mandibular growth in young rabbits: an experimental study

Medpor implants were placed on the periosteum of the mandible in infant rabbits to study their effects on growth. Three months later radiological and histopathological studies were performed in situ and after removal of the mandible. The authors demonstrate that implants did not affect normal development of the mandible; however, there was a decrease in bone thickness and a mononuclear cell reaction was caused where the implant came in contact with the bone.     

Tuberculosis in renal transplant recipients

BACKGROUND: Tuberculosis is an important cause of morbidity and mortality in renal transplant recipients, but there are insufficient data regarding the efficacy and complications of therapy and of INH prophylaxis. METHODS: This study is a retrospective review of the records of 880 renal transplant recipients in two centers in Turkey. RESULTS: Tuberculosis developed in 36 patients (4.1%) at posttransplant 3-111 months, of which 28 were successfully treated. Eight patients (22.2%) died of tuberculosis or complications of anti-tuberculosis therapy. Use of rifampin necessitated a mean of 2-fold increase in the cyclosporine dose, but no allograft rejection occurred due to inadequate cyclosporine levels. Hepatotoxicity developed in eight patients during treatment, two of whom died due to hepatic failure. No risk factor, including age, gender, renal dysfunction, hepatitis C, or past hepatitis B infection, was found to be associated with development of hepatic toxicity. A subgroup of 36 patients with a past history of or radiographic findings suggesting inactive tuberculosis, was considered to be at high risk for developing active disease, of whom 23 were given isoniazid (INH) prophylaxis. None versus 1 of 13 (7.7%) of cases with and without INH prophylaxis, respectively, developed active disease (P>0.05). None of the patients receiving INH had hepatic toxicity or needed modification of cyclosporine dose. CONCLUSIONS: These data show that tuberculosis has a high prevalence in transplant recipients, that it can effectively be treated using rifampin-containing antituberculosis drugs with a close follow-up of serum cyclosporine levels, and that INH prophylaxis is safe but more experience is needed to define the target population.     

Dorsal adipofascial turn-over flap for fingertip amputations

We designed a dorsal adipofascial pedicled flap to cover amputations of the tip of the same digit. This flap includes all the adipofascial tissues from the dermis to the paratenon of the extensor tendons. After elevation of the skin, the adipofascial tissues are raised as a flap and turned over to resurface the exposed bone or joint and then covered with a split thickness skin graft. Ten digital amputations between the distal phalanx proximal to the nail matrix and the mid portion of the middle phalanx were successfully resurfaced with dorsal adipofascial turn-over flaps. All flaps survived completely and the mean follow-up was 11 months. This one-step procedure would seem to be a relatively simple way of achieving early recovery because it does not require the use of distant flaps immobilization of adjacent digits, or homodigital flaps that might jeopardize an already injured finger.     

Effect of botulinum toxin injections into rabbit eye

The aim of this study was to investigate the adverse effects of the intraocular injection of botulinum toxin in rabbits. Intravitreal injections of botulinum toxin A in five doses, 1.25, 2.5, 5, 10, 25 units, were given into five rabbit eyes. The same volume of saline was injected into the second eye of the rabbit as a control. External examination, ophthalmoscopy, visual evoked potentials and electroretinography were done before injection and repeated at the first and second weeks after the injection. There were no significant differences in retinal function between toxin- and saline-injected eyes, neither ophthalmoscopically nor electrophysiologically. Ipsilateral mydriasis developed in the eyes injected with botulinum toxin. This study suggests that botulinum toxin has no harmful effect on retinal function.