C.428_451 dup(24bp) mutation of the ARX gene detected in a Turkish family.

ARX mutations give rise to both syndromic and nonsyndromic forms of mental retardation (MR). We investigated the most common ARX mutations, c.428_451 dup(24bp) and c.333ins (GCG)7 in a series of 370 mentally retarded FMR1 (CGG)n expansion mutation negative Turkish patients using PCR amplification and high resolution MetaPhor agarose gel electrophoresis. Sequence analysis was also performed for confirmation and discrimination of the mutations. One patient representing non-syndromic X-linked MR showed an abnormal band pattern on agarose gel and sequence analysis of exon 2 of the ARX gene revealed that the patient had the c.428_451 dup(24bp) mutation. When we screened the family members, we found that his sister and mother were also carrier for the same mutation. The proband showed mild MR and subtle clinical findings like dysarthria and lack of fine motor functions. In conclusion, the patients with weak fine motor skills and positive family history for X-linked MR should be screened for the most common ARX gene mutations.

C677T polymorphism of the methylenetetrahydrofolate reductase gene does not affect folic acid, vitamin B12, and homocysteine serum levels in Turkish children with neural tube defects.

Association between neural tube defects (NTDs) and C677T polymorphism of the methylenetetrahydrofolate reductase (MTHFR) gene was suspected, because the MTHFR gene codes for a key enzyme in folate metabolism. Its deficiency usually leads to significant reductions in plasma concentrations of folate, vitamin B(12) and methionine, whereas homocysteine levels are increased. We examined folate, vitamin B(12) and homocysteine serum concentrations and polymorphism of the C677T MTHFR gene in Turkish children with neural tube defects. Thirty-three children with NTDs, 26 mothers and 48 healthy individuals were studied. C677T MTHFR polymorphism was determined by melting curve analyses (LightCycler). The levels of folate, vitamin B(12) and homocysteine serum concentrations in NTDs were evaluated and compared, along with information concerning alleles of the MTHFR gene. C677T allele frequencies in NTD children and their mothers were similar to those found in controls. Serum folate and vitamin B(12) concentrations were significantly higher in NTD children than that of controls. Serum homocysteine concentrations were not significantly higher in NTD children and mothers. We concluded that C677T MTHFR gene polymorphism does not affect folic acid, vitamin B(12) and homocysteine metabolism in Turkish children with NTDs. C677T polymorphism of the MTHFR gene cannot be regarded as a major risk factor for NTDs in Turkish children.

Presumed ocular tuberculosis in an immunocompetent eight-year-old boy.

In recent years, tuberculosis has re-emerged as a serious public health problem, raising the possibility that tuberculous eye disease may also have become more prevalent. Ocular tuberculosis usually occurs in apparently healthy individuals. It is rarely observed in patients with active pulmonary disease. An eight-year-old boy was admitted to our department because of chronic granulomatous anterior uveitis on his left eye. His medical history was unremarkable. There were no systemic symptoms of tuberculosis. He had a positive purified protein derivative test reaction. In our case, the diagnosis of ocular tuberculosis was presumptive and depended upon indirect evidence. The patient was started on anti-tuberculosis therapy with three drugs, which were continued for 12 months, with complete healing of the ocular lesions, including a marked improvement in the gait of the patient. Tuberculosis remains one of the most important causes of morbidity and mortality in developing countries.

Pleural effusion: a rare complication of hepatitis A.

Hepatitis A (HAV) infection, which is the most common form of hepatitis in the paediatric age group and which sometimes has a fulminant course, is endemic in Turkey, constituting one of the country's important health problems. Pleural effusion also represents a rare benign complication of acute HAV infections. We describe here a case of Hepatitis A who developed pleural effusion.

A structured dynamic model for the baculovirus infection process in insect-cell reactor configurations.

A mathematical description of the infection of insect cells with baculovirus in a continuously operated reactor configuration is presented. The reactor configuration consists of one bioreactor in which insect cells (Spodoptera frugiperda) are grown followed by one or two bioreactors in which cells are infected by a baculovirus (Autographa californica nuclear polyhedrosis virus). It was demonstrated that the so-called passage effect is responsible for the observed difference in run time between a configuration with one or with two infection vessels. Furthermore, a model is presented based on the hypothesis that the limited run time of series of continuously operated bioreactors is associated with the occurrence of a virus particle (so-called virion) that is defective and has interfering properties. With the assumption that not all nonoccluded virions are capable of establishing a correct infection leading to new virus production, infection levels in continuously operated reactor configurations could be described well with the model.