Polymorphisms in the IL28B gene (rs12979860, rs8099917) and the virological response to pegylated interferon therapy in hepatitis D virus patients.

AIM: Few data are available regarding the effects of interleukin 28B (IL28B) polymorphisms in chronic hepatitis D (CHD) patients. This study investigated the relationship between IL28B poly-morphisms and the response of patients with CHD infections to pegylated interferon (PEG-IFN) therapy. MATERIALS AND METHODS: A total of 101 CHD patients were -selected, 80 of whom (46 males ; median age 41 years) satisfied the inclusion criteria and were enrolled in the study. Thirty-seven patients were treated with peg-IFNα for at least 12 months and were followed for a median of 18 months (range, 12-30 months). The primary treatment endpoint was the suppression of HDV replication, as documented by the loss of detectable HDV RNA in serum. Genotyping was used to analyse the IL28B polymorphisms rs12979860 and rs8099917 according to the virological response. RESULTS: After treatment, a sustained viral response (SVR) was achieved in 19 (51%) of the patients treated with PEG-INF. The IL28B genotypes in the 80 patients were as follows : CC in 36 (45%), CT in 33 (41%) and TT in 11 (14%) for rs12979860, and GG in 4 (5%), GT in 27 (34%) and TT in 49 (61%) for rs8099917. SVR was achieved in 5 (26%), 10 (53%) and 4 (21%) patients with CC, CT and TT at rs12979860, respectively, and one (5%), nine (47%) and nine (47%) patients with GG, GT and TT at rs8099917, respectively. There were differences in the SVR among genotypes (rs12979860 and rs8099917 ; chi-squared test, p = 0.047). CONCLUSION: IL28B predicts the PEG-IFN response in patients with CHD infection.

Identification of a U2HR gene mutation in Turkish families with Marie Unna hereditary hypotrichosis.

Marie Unna hereditary hypotrichosis (MUHH) is an autosomal dominant form of isolated alopecia. The disorder is characterized by the absence or scarcity of scalp hair, eyebrows and eyelashes at birth. Coarse wiry hair begins to grow during childhood, but this is followed by progressive hair loss, which usually begins around puberty. A recent study identified mutations in U2HR, an inhibitory upstream open reading frame in the 5'-untranslated region of the human hairless gene. We investigated three reportedly unrelated Turkish multigeneration families with MUHH. Using direct sequencing of U2HR we were able to identify the c. 2T>A (p.M1K) mutation in one index patient of each family. The mutation cosegregates perfectly with the disease in all members of the families. To our knowledge, this is the first time that a mutation in U2HR has been identified in families from the Middle East. The observation of a common mutation is suggestive of a possible founder effect.

The effects of dantrolene alone or in combination with nimodipine in glutamate-induced neurotoxicity in cerebellar granular cell cultures of rat pups.

Despite the existence of some positive and negative reports on dantrolene in ischemic states, combined application of an endoplasmic reticulum Ca2+ release inhibitor and a calcium channel blocker has not yet been elucidated. In the present study, we have investigated the role of dantrolene in subsequent doses alone or in coexistence with the dihydropyridine calcium antagonist nimodipine (10(-4) M concentration) in glutamate-induced (10(-7) M) neurotoxicity in cerebellar granular cell cultures of rat pups. Glutamate induced neuronal cell death at a concentration of 10(-7) M. Despite the fact that none of the groups tested were able to reverse cell death to control values, dantrolene was found to be effective in preventing glutamate toxicity in cerebellar cultures of rat pups. The protective effect of dantrolene potentialized in combination with nimodipine at all doses tested. The most effective dose of dantrolene was found to be 10(-4)M in combination with nimodipine. As a result, both extracellular and internal calcium stores play important roles in the genesis of neuronal cell death induced by glutamate.

Effects of salicylic acid in glutamate- and kainic acid-induced neurotoxicity in cerebellar granular cell culture of rats.

Glutamate (10(-7)m) and one of its non-NMDA receptor agonists, kainic acid (10(-4)m), were administered to rat cerebellar granular cell cultures, and the neuroprotective role of salicylic acid was examined. Glutamate induced 38.58 +/- 1.45% neuronal cell death while kainic acid induced only 21.4 +/- 2.01% despite being 1000 times more concentrated. The most effective dose for the neuroprotective effect of salicylate in glutamate-induced neurotoxicity was 10(-5)m and it had no protective effect at 10(-7)m. With kainic acid-induced toxicity, 10(-6)m salicylate had no protective effect but 10(-5)m and. 10(-4)m salicylic acid were very effective against kainic acid-induced toxicity. As an OH-trapping agent, salicylate had a protective role in NMDA and non-NMDA receptor-activated neuronal cell death. The present study gives some important clues about oxygen free radical generation having an important role in glutamate- and kainic acid-induced neurotoxicity. On the other hand, the neuroprotective effects of salicylic acid in the present study may depend on the pH alterations in salicylic acid solutions.

The effects of melatonin in glutamate-induced neurotoxicity of rat cerebellar granular cell culture.

In the present study, melatonin was tested in subsequent doses in glutamate induced neurotoxicity in cerebellar granular cell culture of rat pups. Glutamate at 10(-7) M was found to induce neuronal cell death. The dead cell score was 2.75+/-0.7 in the control, while it was found to be 35.12+/-1.8 in the glutamate-administered group (P<0.0001). Melatonin very potently blocked glutamate neurotoxicity at all doses tested, with 10(-3) M, the highest dose tested, being the most effective. Glutamate may exert a neuroprotective effect by blocking one or more steps of the oxidation cascade in neurons and this effect may be blocked by melatonin.

Effects of norepinephrine on NMDA-induced neurotoxicity in cerebellar granular cell culture of rat pups.

In this study, norepinephrine was tested in 0.1, 1, 10, 25 and 50 microM doses in 100 microM NMDA toxicity on cerebellar granular cell culture of rats. NMDA in 100 microM concentration induced cell death significantly with respect to controls. Death cell population was 1.08 +/- 0.44% in control and 22.15 +/- 2.46% in 100 microM NMDA (P < 0.0001). None of the norepinephrine concentrations administrated 15 min prior to NMDA was able to reduce death cell scores to control levels. Results were 8.75 +/- 0.83% in 0.1 microM, 7.0 +/- 1.01% in 1 microM, 17.25 +/- 1.31% in 10 microM, 35.5 +/- 1.38% in 25 microM and 17.9 +/- 1.72% in 50 microM norepinephrine plus 100 microM NMDA administrated groups (P < 0.0001 for all with respect to control). Labetalol, as an alpha and beta blocker in 0.5 microM concentration which was given 15 min prior to norepinephrine was able to block the effects of it. In comparison with 100 microM NMDA administered group, only low doses of norepinephrine reduced the death cell scores significantly (for 0.1 and 1 microM norepinephrine plus NMDA groups; P < 0.0001). For 10 and 50 microM norepinephrine plus NMDA groups, death cell scores were found statistically insignificant from the NMDA-administered group (P > 0.05 for both) while for the 25 microM norepinephrine plus NMDA group, the death cell score was found to be statistically increased (P < 0.0001).

Response to nimodipine in caffeine-induced neurotoxicity in cerebellar granular cell culture of rat pups.

Methylxanthines (theophylline, theobromine and caffeine) are widely used as central nervous system stimulants and caffeine is used in the treatment of apnea in newborns. Plasma therapeutic concentration of caffeine is around 110 microM. Caffeine diffuses the blood brain barrier easily, increasing oxygen consumption in neurones and leading to cell death. In the present study, 4-7-day-old rats were used to obtain cerebellar granular cell cultures. Caffeine was used 50, 150, 250 and 350 microM concentrations and the most toxic dose for it was found to be 350 microM. Death cell scores were 0.9+/-0.63 for control, 1.1+/-0.63 for 50 microM, 0.89+/-0.47 for 150 microM (P>0.05 for both), 3.84+/-0.8 for 250 microM (P=0.024) and 6.2+/-0. 86 for 350 microM (P=0.001) caffeine concentrations. The role of voltage-dependent calcium channels in caffeine-induced neurotoxicity was tested with the doses of 100 and 200 microM nimodipine 45 min before or after the 350 microM caffeine. Both doses of nimodipine after caffeine administration were found to be ineffective in blocking neurotoxicity. Doses administered 45 min prior to caffeine, reduced death cell score to 0.89+/-0.23 (P=0.000) for 100 microM nimodipine and 2.35+/-0.96 (P=0.000) for 200 microM nimodipine administration into the cultures. A dose-dependent manner of nimodipine in ischemic states is well-known. In the light of these results, nimodipine may be used in the treatment of newborn apneas together with caffeine to prevent neurotoxic side effects of high or repeated doses of it.

Nimodipine improves kainic acid induced neurotoxicity in cerebellar granular cell culture: a double-blind dose-response study.

The neuroprotective role of nimodipine was tested in kainic acid (50 and 100 microM) induced neurotoxicity in cerebellar granular cell cultures of 4 to 7 day-old rat pups. Nimodipine was applied in 50, 100 and 200 microM concentrations. Kainate, in either dose, induced cerebellar granular cell death in respect to controls and the results were statistically significant (P = 0.000 for both doses). However, kainic acid in 100 microM concentration led to higher rates of cell death than 50 microM (P = 0.017). The neuroprotective role of nimodipine in kainate induced neurotoxicity was dose dependent. Kainate toxicity in 50 microM concentration was blocked by 50 and 100 microM nimodipine concentrations (P = 0.006 and P = 0.002, respectively) while 200 microM nimodipine was found ineffective. The most effective nimodipine dose for 100 microM kainic acid neurotoxicity was 200 microM (P = 0.000) while 50 and 100 microM concentrations of nimodipine were found ineffective. In this study, we have proven the dose-dependent neuroprotective role of nimodipine in kainate induced neurotoxicity in cerebellar granular cell cultures of rat pups.