Mehmet Bosnak

The role of nitric oxide in the anticonvulsant effects of pyridoxine on penicillin-induced epileptiform activity in rats

The present study was conducted to identify the role of nitric oxide (NO) in the anticonvulsant effects of pyridoxine hydrochloride on penicillin-induced epileptiform activity in rats. A single microinjection of penicillin (500 units) into the left sensorimotor cortex induced epileptiform activity within 2-4 min, progressing to full seizure activity lasting about 3-5h. Thirty minutes after penicillin injection, 20, 40, 80, and 160 mg/kg of pyridoxine hydrochloride was administered intraperitoneally (i.p.). Pyridoxine significantly reduced the frequency of penicillin-induced epileptiform activity. A low dose of pyridoxine (40 mg/kg) was the most effective in reducing both the frequency and amplitude of epileptiform activity. The effect of systemic administration of nitric oxide synthase (NOS) inhibitors, non-selective N(G)-nitro-L-arginine methyl ester (L-NAME), selective neuronal NOS inhibitor, 7-nitroindazole (7-NI) and NO substrate, L-arginine on anticonvulsive effects of pyridoxine was investigated. The administration of L-arginine (500 mg/kg, i.p.) and 7-NI (25 and 50 mg/kg, i.p.) significantly decreased the frequency of epileptiform electrocorticographical (ECoG) activity while administration of L-NAME (60 mg/kg, i.p.) and the inactive form of arginine (D-arginine) did not influence it. The administration of L-NAME (60 mg/kg, i.p.) 15 min before pyridoxine (40 mg/kg i.p.) application reversed the anticonvulsant effects of pyridoxine whereas 7-NI (25 and 50 mg/kg, i.p.) did not influence it. The same dose of its inactive enantiomer N(G)-nitro-D-arginine methyl ester (d-NAME) failed to reverse the anticonvulsant effects of pyridoxine. The administration of L-arginine (500 mg/kg, i.p.) did not affect the frequency of epileptiform ECoG activity in the pyridoxine administered group. L-arginine did not reverse the anticonvulsant effect of 7-NI in the penicillin and pyridoxine administered groups. The results of present study indicate that the inhibitory effect on the anticonvulsant activity of pyridoxine against penicillin-induced epileptiform activity was produced by L-NAME, not by 7-NI, and is probably not related to the decrease of NOS activity in the brain.

TOTAL BRAIN TISSUE SIALIC ACID LEVELS DUE TO GLUTATHIONE EFFECT IN EXPERIMENTAL EPILEPSY

Epilepsy can be described as a group of neurological disorders, characterized by recurrent episodes of convulsive seizures, loss of consciousness, sensory disturbances, abnormal behavior, or all of these. Altered glutathione metabolism in association with increased oxidative stress has been implicated in the pathogenesis of many diseases such as seizures. It is therefore reasonable to propose that sialic acid levels can be affected by this pathological state or, alternately, by seizures. The present study showed that the sialic acid levels were significantly different between the experimental groups as well as in the subgroup analysis. The results suggest that glutathione may have a neuroprotective effect by decreasing sialic acid levels in mice brain.

Antiepileptogenic Effects of Glutathione Against Increased Brain ADA in PTZ-Induced Epilepsy

Adenosine has been shown to play a significant role as a modulator of neuronal activity in convulsive disorders, acting as an endogenous anticonvulsant agent. Any change in adenosine deaminase (ADA) levels will reflect to adenosine levels. In the present study, we have investigated the effect of glutathione on brain tissue ADA levels due to seizures induced by convulsive and subconvulsive dose of pentylenetetrazol (PTZ) in mice. ADA levels due to seizures induced by convulsive and subconvulsive pentylenetetrazol were measured using the Giusti method. ADA levels were higher in the experimental epilepsy groups than in the control and sham groups. ADA levels significantly decreased in the glutathione groups, which may have antiseizure effects. Decreased levels of ADA would be due to increased adenosine levels, protecting against oxidative stress.

Therapeutic plasma exchange in primary hemophagocytic lymphohistiocytosis: Reports of two cases and a review of the literature

We report two children who were diagnosed as having primary hemophagocytic syndrome and who successfully underwent therapeutic plasma exchange (TPE). The first patient was a 6-month-old girl diagnosed with HLH who was admitted to the pediatric intensive care unit. The patients clinical condition worsened on the 9th day of the HLH-2004 treatment protocol. Her ferritin level was found 50.000 ng/mL, and TPE was performed for 9 sessions, after which her clinical condition and laboratory findings improved. The patient is still on the HLH-2004 protocol and waits for a suitable stem cell transplantation donor. Case 2 involved a Syrian girl with HLH under follow-up who was receiving the HLH-2004 treatment protocol for reactivation. She presented to emergency department with fever, where her ferritin level was measured greater than 100.000 ng/mL; she was then transferred to the pediatric intensive care unit where four sessions of TPE were performed, after which her clinical condition and laboratory findings improved. However, the patient was admitted again one month later with gastrointestinal bleeding and died despite all efforts. By describing these two cases, we wish to emphasize that TPE can produce a rapid improvement until the time of stem cell transplantation in patients with hemophagocytic syndrome who do not respond to traditional treatments.

THE EFFECT OF PROGESTERONE ON TOTAL BRAIN TISSUE SIALIC ACID LEVELS IN EXPERIMENTAL EPILEPSY

Epilepsy, the most common neurological disorder worldwide, changing cellular interactions and connectivity may have effects on sialic acid levels. A total of 80 mice were separated into 8 groups: the sham, control, pentylentetrazole (PTZ), PTZ plus progesterone, five dose progesterone, single dose progesterone, kindling, and kindling plus progesterone groups. Brains of each mice were extracted and were divided into five parts. The sialic acid levels were significantly different between the groups and also in the subgroups. The results suggested that progesterone may have an anti-seizure effect by decreasing sialic acid levels in mice. Further studies are needed to evaluate the role of progesterone on sialic acid levels and its role in the epilepsy pathogenesis.

Hypophosphatemia associated risk factors in pediatric intensive care patients

Şan ES, Erdoğan S, Boşnak M, Şan M. Hypophosphatemia associated risk factors in pediatric intensive care patients. Turk J Pediatr 2017; 59: 35-41. The aim of this work is to determine the prevalence and risk factors of hypophosphatemia in pediatric patients admitted to intensive care unit. The study was performed prospectively in patients admitted to the Pediatric Intensive Care Unit between June 2014 and December 2014. Fifty-seven patients were included in the study. The mean age of the study population was 24 months (2-192 months); 25 patients (43.9%) were male and 32 were female (56.1%). The mean body weight z-score was -1.47 ± 2.23, and 23 (40.4%) patients had malnutrition. On admission 16 (28.1%) patients had hypophosphatemia. There were no statistically significant differences between the hypophosphatemic patient group and normophosphatemic patient groups in terms of demographic and clinical characteristics. There were also no significant differences between the two groups in terms of risk factors. Potassium and creatinine levels were significantly lower in the hypophosphatemic group, compared to the normophosphatemic group. According to a multivariate logistic regression analysis, risk factors for hypophosphatemia were low potassium level (OR: 16.76; 95% CI: 2.09 - 134.72; p: 0.008), malignant solid tumors (OR: 52.40; 95% CI: 2.04 - 1,344.32; p: 0.017, p: 0.036). and female gender (OR: 6.18; 95% CI: 1.12 - 34.00; p: 0.036). Prospective studies with larger sample size should be conducted to study the prevalence and risk factors of hypophosphatemia at pediatric intensive care unit.

Respiratuvar depression after accidental nasal ingestion of brimonidine eye drops in infant

Objectives Brimonidine tartrate is an alpha-2 agonist used for glaucoma treatment. It can lead to serious poisoning symptoms when misused by children. Case report In this case report, 3 months-old male patient with severe central nervous system depression and respiratory arrest as a result of accidentally nasal instillation of 1 cc brimonidine tartrate that benefited from mechanic ventilation and naloxone treatment was presented. Conclusion This case report suggested, that misuse of nasal brimonidine eye drop could result in serious respiratory distress and central nervous system depression. Mechanical ventilation and naloxone administration can be useful for these patients.

A case of paralytic rabies mimicking Guillain-Barre syndrome

Rabies is an acute, fatal viral infection of the central nervous system, and one of the oldest zoonotic diseases in human history. A Syrian boy aged 14 had been hospitalized for 2 days with a preliminary diagnosis of Guillain-Barre syndrome because of muscle weakness that spread rapidly to the upper extremities. He was transferred to our unit when the muscle weakness worsened. Respiratory failure developed following admission to the ICU, and the patient was intubated and given ventilator support. Ascending paralysis and albuminocytologic dissociation in the cerebrospinal fluid (CSF) examination suggested a preliminary diagnosis of Guillain-Barre syndrome and plasmapheresis treatment was initiated. No clinical improvement was achieved despite plasmapheresis. On the 10th day of hospitalization, we learned that he had been bitten on the ankle by a stray dog in Syria 2 months ago and had not received prophylaxis. Suspecting that this might be a case of rabies, body fluid samples of the patient were sent to the National Reference Laboratory. The patient died on the 12th day of admission. A postmortem brain biopsy was taken, and Negri bodies were detected. This case report emphasizes that rabies should be considered in the differential diagnosis of patients presenting with paralysis.

Hemlock (Conium Maculatum) Poisoning In A Child

SUMMARY Poison hemlock (Conium maculatum) is a plant that is poisonous for humans and animals. Accidental ingestion of the plant may result in central nervous system depression, respiratory failure, acute rhabdomyolysis, acute renal failure and even death. The main treatment of hemlock poisoning is supportive care. The case of a 6-year-old girl who was admitted to the emergency department with complaints of burning sensation in mouth, hypersalivation, tremor in hands and ataxia after ingestion of poison hemlock is presented here with clinical and laboratory features. In this case, we aim to report that accidental ingestion of plants resembling vegetables that are consumed daily can lead to serious complications and even death.