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Dive into the research topics where Hakan Gumus is active.

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Featured researches published by Hakan Gumus.


Hormone Research in Paediatrics | 2006

Increased Aortic Intima-Media Thickness Is Related to Lipid Profile in Newborns with Intrauterine Growth Restriction

Esad Koklu; Selim Kurtoglu; Mustafa Akcakus; Selmin Koklu; Derya Büyükkayhan; Hakan Gumus; Ali Yikilmaz

Background and Aim: Low birth-weight is known to be associated with an increase in cardiovascular risk similar to that seen with major environmental risk factors, such as cigarette smoking or hypertension. Much epidemiological evidence has linked low birth-weight with hypertriglyceridaemia. Method: We measured aortic wall thickness by ultrasonography and lipid profile in 40 newborn babies with intrauterine growth restriction and 40 controls. Results: Maximum and mean aortic intima-media thickness were significantly higher in the babies with intrauterine growth retardation (0.58 ± 0.06, 0.52 ± 0.03 mm, respectively) than in controls (0.44 ± 0.05, 0.40 ± 0.03 mm, p < 0.0001, p < 0.0001, respectively), more so after adjustment for birth-weight (maximum intima-media thickness: 0.23 ± 0.03 mm/kg vs. 0.12 ± 0.02 mm/kg, p < 0.0001; mean intima-media thickness: 0.21 ± 0.02 mm/kg vs. 0.11 ± 0.01 mm/kg, p < 0·0001). Serum triglyceride levels were significantly higher in the intrauterine growth retardation group (48.9 ± 14.8 mg/dl) compared with the control group (32.5 ± 9.8 mg/dl, p < 0.0001). The mean body mass index, prepregnancy weight, weight gain during pregnancy, maternal LDL cholesterol level and, height of the mothers were significantly lower in the intrauterine growth retardation group compared with the control group. For maximum aIMT, significant associations included the ponderal index (p = <0.01), length (p = 0.01) and serum triglyceride levels of infants (p = 0.02). Conclusion: Newborn babies with growth restriction have significant maximum aortic thickening with hypertriglyceridaemia, suggesting that prenatal events might predispose to later cardiovascular risk.


Neurological Sciences | 2010

Reversible posterior leukoencephalopathy syndrome in childhood: report of nine cases and review of the literature

Hakan Gumus; Hüseyin Per; Ali Yikilmaz

Reversible posterior leukoencephalopathy syndrome (RPLS) is recently described disorder with typical radiological findings in the posterior regions of the cerebral hemisphere and cerebellum. Its clinical symptoms include headache, decreased alertness, mental abnormalities, such as confusion, diminished spontaneity of speech, and changed behavior ranging from drowsiness to stupor, seizures, vomiting and abnormalities of visual perception like cortical blindness. RPLS is caused by various heterogeneous factors, the commonest being hypertension, followed by non-hypertensive causes such as eclampsia, renal diseases and immunosuppressive therapy. We presented nine patients with RPLS who had primary diagnoses such as acute post-streptococcal glomerulonephritis, idiopathic hypertension, the performing of intravenous immunoglobulin for infection with crescentic glomerulonephritis, erythrocyte transfusion for severe iron deficiency, l-asparaginase treatment for acute lymphoblastic leukemia and performing of granulocyte-colony stimulating factor for ulcerative colitis due to neutropenia. Early recognition of RPLS as complication during different diseases and therapy in childhood may facilitate precise diagnosis and appropriate treatment.


Neurosurgical Review | 2006

Torticollis secondary to posterior fossa and cervical spinal cord tumors: report of five cases and literature review

Hüseyin Per; Hakan Gumus; Bülent Tucer; Ali Yikilmaz; Olgun Kontas; Abdulhakim Coskun; Ali Kurtsoy

Torticollis is either congenital or acquired in childhood. Acquired torticollis is not a diagnosis but rather a sign of an underlying disorder. The causes of acquired torticollis include ligamentous, muscular, osseous, ocular, psychiatric, and neurologic disorders and may be a symptom of significant abnormalities of the spinal cord and brain, such as spinal syrinx or central nervous system neoplasia. Torticollis is rarely considered to be an initial clinical presentation of posterior fossa and cervical spinal cord tumors. We report five cases of pediatric tumors with torticollis at the onset: an astrocytoma originating from the medulla oblongata, another presumptive astrocytoma of the spinal cord located between C1 and C6 cervical vertebrae (not operated), an ependymoma located throughout the whole cervical spinal cord extending into the bulbomedullary junction, an astrocytoma originating from the bulbus and extending into the posterior fossa, and another case of a eosinophilic granuloma located extradurally through the anterior and posterior portions of the vertebral bodies from C3 to C7 producing the collapse of the sixth cervical vertebra. All five cases were seen in children, aged between 3 and 12 years. All these cases reflect the misinterpretation of this neurological sign and the lack of association with the possibility of spinal or posterior fossa tumor. This delay in the diagnosis of these diseases led to progressive neurological deterioration and to the increase in the tumor size, which made surgical intervention difficult and the prognosis unfavorable. Although torticollis secondary to tumors is rarely seen, it is necessary to be kept in mind in the differential diagnosis.


Neuron | 2014

Mutations in KATNB1 Cause Complex Cerebral Malformations by Disrupting Asymmetrically Dividing Neural Progenitors

Ahmet Okay Caglayan; Ashleigh E. Schaffer; Chiswili Chabu; Octavian Henegariu; Fernando Vonhoff; Gozde Tugce Akgumus; Sayoko Nishimura; Wenqi Han; Shu Tu; Burçin Baran; Hakan Gumus; Cengiz Dilber; Maha S. Zaki; Heba A.A. Hossni; Jean-Baptiste Rivière; Hülya Kayserili; Emily Spencer; Rasim Ozgur Rosti; Jana Schroth; Hüseyin Per; Caner Caglar; Çağri Çağlar; Duygu Dölen; Jacob F. Baranoski; Frank J. Minja; E. Zeynep Erson-Omay; Shrikant Mane; Richard P. Lifton; Tian Xu; Haig Keshishian

Exome sequencing analysis of over 2,000 children with complex malformations of cortical development identified five independent (four homozygous and one compound heterozygous) deleterious mutations in KATNB1, encoding the regulatory subunit of the microtubule-severing enzyme Katanin. Mitotic spindle formation is defective in patient-derived fibroblasts, a consequence of disrupted interactions of mutant KATNB1 with KATNA1, the catalytic subunit of Katanin, and other microtubule-associated proteins. Loss of KATNB1 orthologs in zebrafish (katnb1) and flies (kat80) results in microcephaly, recapitulating the human phenotype. In the developing Drosophila optic lobe, kat80 loss specifically affects the asymmetrically dividing neuroblasts, which display supernumerary centrosomes and spindle abnormalities during mitosis, leading to cell cycle progression delays and reduced cell numbers. Furthermore, kat80 depletion results in dendritic arborization defects in sensory and motor neurons, affecting neural architecture. Taken together, we provide insight into the mechanisms by which KATNB1 mutations cause human cerebral cortical malformations, demonstrating its fundamental role during brain development.


Journal of Asthma | 2008

The role of lipoxin A4 in exercise-induced bronchoconstriction in asthma.

Fulya Tahan; Recep Saraymen; Hakan Gumus

Background. The pathogenesis of exercise-induced bronchoconstriction in asthma is incompletely understood, and the role of lipoxin A4 has not been investigated. Objective. To investigate the involvement of lipoxin A4 in exercise-induced bronchoconstriction. Methods. Two groups of children were enrolled in the study: asthmatic children with positive (n = 12) and negative (n = 8) responses to exercise. Levels of lipoxin A4 were determined in plasma before and immediately after exercise challenge using enzyme-linked immunosorbent assay. Results. No significant difference was observed in the pre-exercise lipoxin A4 levels among the groups (p > 0.05). A significant difference was observed in the postexercise lipoxin A4 levels between the two groups (p = 0.041). We also observed significant decreases in plasma lipoxin A4 levels immediately after exercise challenge both in asthmatic children with positive responses to exercise (p = 0.013) and negative responses to exercise (p = 0.05). But these levels were significantly higher in asthmatic children with negative responses to exercise (p = 0.041). There was an inverse correlation between lipoxin A4 levels and a reduction in forced expiratory volume at one second percent after exercise (p = 0.045, r = −0.465). Conclusion. Our results are the first demonstration of the lower levels of lipoxin A4 associated with exercise-induced bronchoconstriction in asthma. We hypothesize that the development of exercise-induced bronchoconstriction in asthmatic children may be in relation to a reduced endogenous lipoxin biosynthetic capability. Lipoxin mimetics and related compounds could provide novel therapeutic approaches to the treatment of exercise-induced bronchoconstriction in asthma.


Annals of Saudi Medicine | 2005

The association of plasma homocysteine levels with serum leptin and apolipoprotein B levels in childhood obesity.

Figen Narin; Mehmet Emre Atabek; Musa Karakukcu; Nazmi Narin; Selim Kurtoglu; Hakan Gumus; Bekir Çoksevim; Rusen Erez

BACKGROUND An elevated plasma total homocysteine (tHcy) level has recently been established as an independent risk factor for thrombosis and vascular disease. However, the relationship between hyperhomocysteinemia and cardiovascular disease and obesity remains controversial. The aim of the study was to investigate a possible relationship between plasma tHcy levels and measures of childhood obesity. SUBJECTS AND METHODS Forty children and adolescents with exogenous obesity and 20 non-obese subjects in an age-and sex-matched control group were investigated. Fasting samples were collected for plasma tHcy, serum insulin, leptin, vitamin B12, folate, creatinine and lipid parameters. Anthropometric characteristics and body compositions were assessed in both groups. RESULTS The obese patients had significantly higher tHcy levels than the non-obese controls (14.3±11.8 μmol/L vs 8.7±5.9 μmol/L; P=0.017). In both groups, plasma tHcy was positively related to serum leptin, but serum apolipoprotein B (apo B) levels were positively related to plasma tHcy levels only in obese patients. CONCLUSIONS Our study demonstrates for the first time that leptin and apo B are main correlates of tHcy in obese children and adolescents and suggests that hyperleptinemia and increased apo B may contribute to impairment of tHcy metabolism in childhood obesity.


Brain & Development | 2013

Clinical spectrum of the pseudotumor cerebri in children: Etiological, clinical features, treatment and prognosis

Hüseyin Per; Mehmet Canpolat; Hakan Gumus; Hatice Gamze Poyrazoğlu; Ali Yikilmaz; Sarper Karakucuk; Hakki Dogan

OBJECTIVE Pseudotumor cerebri (PTC) is a clinical condition characterized by signs and symptoms of increased intracranial pressure, such as headache and papilledema. Our aim was to investigate the etiological and clinical features of pseudotumor cerebri (PTC) in children. MATERIALS AND METHOD We performed a comprehensive analysis of epidemiology, diagnostic work-up, therapy, and clinical follow-up in 42 consecutive patients. RESULTS Totally 42 patients diagnosed with PTC [27 (64.3%) females and 15 (35.7%) males] were included in the study. The average age of the symptoms onset was 10.79±3.43 years (range from 12 months to 17 years). Obesity was found in eleven (26.2%) of them. Two of the patients had familial mediterranean fever, two of them had posttraumatic PTC. The following diseases were one patient, respectively; mycophenolate mofetil-induced PTC, hypervitaminosis A induced PTC, corticosteroid induced withdrawal due to nephritic syndrome, use of oral contraceptives, Guillain-Barre syndrome, urinary tract infection, varicella-zoster virus infection and dural venous sinus thrombosis associated with otitis media. The most common symptom was headache, recorded in 76.2% of the patients. All patients were treated medically. Three patients in our group also required a ventriculoperitoneal shunt. CONCLUSION Pseudotumor cerebri is an avoidable cause of visual loss, both in adults and children. Pre-pubertal obese girls are more common. Medical therapy appeared to be successful in treating pediatric PTC in most patients. Nevertheless, despite adequate treatment, children can rarely experience loss of visual field and acuity; thus, prompt diagnosis and management are important.


Pediatric Anesthesia | 2011

The comparison of the effects of dexmedetomidine and midazolam sedation on electroencephalography in pediatric patients with febrile convulsion

Recep Aksu; Aynur Akin; Cihangir Bicer; Hakan Gumus; Gulen Guler; Hüseyin Per; Adnan Bayram; Adem Boyaci

Background:  When electroencephalogram (EEG) activity is recorded for diagnostic purposes, the effects of sedative drugs on EEG activity should be minimal. This study compares the sedative efficacy and EEG effects of dexmedetomidine and midazolam.


Nephrology Dialysis Transplantation | 2010

MEFV gene compound heterozygous mutations in familial Mediterranean fever phenotype: a retrospective clinical and molecular study

Ahmet Okay Caglayan; Fatma Demiryilmaz; Isilay Ozyazgan; Hakan Gumus

BACKGROUND Familial Mediterranean fever (FMF) is an autosomal-recessive inherited inflammatory disease caused by mutations in the MEFV gene that encodes pyrin/marenostrin. It is characterized by recurrent short episodes of fever, abdominal pain and serositis affecting mainly Mediterranean and Middle Eastern populations. We determined the frequency of the compound heterozygous mutations which has been rarely reported. The present study not only investigated clinical features of child-onset FMF patients with compound heterozygous mutations but also determined whether there is a phenotype-genotype correlation in the same patient population. METHODS The medical records of 66 heterozygous patients with FMF were retrospectively reviewed and assessed. Patients were investigated regarding the mutation type, clinical characteristics at the time of inflammatory attacks such as fever, abdominal pain, arthritis, chest pain, erysipelas-like erythema and oedema, epidemiological data, consanguinity, severity score and family history of FMF and amyloidosis. RESULTS The most frequent mutation was M694V, identified in 32% of the alleles examined, followed by E148Q in 20.6%, V726A in 17% and M680I in 14.5%, respectively. Consequently, we determined that P369S (n = 10; 8%) was the most frequent rare mutation in Turkish FMF patients. Frequency of the other rare mutations were R761H (3%), F479L (3%), A744S (1.5%) and K695R (0.7%). Fever was seen in 96.5%, abdominal pain in 98.5%, arthralgia in 85%, chest pain in 45.5% and erysipelas-like lesions in 23%. None of these patients had amyloidosis, but 16 had a family history of chronic renal failure, 44% had vomiting and 35% had diarrhoea during the attack. Although regular colchicine treatment was effective in 83% of the patients, the percentage of patients that did not start colchicine therapy was 18%. In addition, the patients were divided into four groups according to the presence of the mutation types and we compared genotype-phenotype correlations. CONCLUSIONS We suggest that regular colchicine therapy may be administered to symptomatic patients with MEVF gene compound heterozygous mutations, regardless of the mutation type.


Journal of Child Neurology | 2007

Iatrogenic Epidermoid Tumor: Late Complication of Lumbar Puncture:

Hüseyin Per; Hakan Gumus; Ali Yikilmaz; Ali Kurtsoy

Intraspinal epidermoid tumors can be congenital and acquired. Acquired intraspinal epidermoid tumors are extremely rare. Epidermal elements are implanted into the arachnoid space by trauma, spinal anesthesia, surgery, bullet wounds, myelography, or lumbar puncture. Approximately 40% of acquired epidermoid tumors are considered a late complication of lumbar puncture. The authors report the case of an 8-year-old boy who presented with a 1-year history of back and hip pain and radiating pain to both thighs posterior. Lumbar puncture was performed in the neonatal intensive care unit to rule out meningitis in the patients past medical history. The patient underwent total surgical excision of the epidermoid tumor. Pathologic examination revealed the diagnosis of epidermoid tumor. Keywords: intraspinal epidermoid tumor; lumbar puncture; children

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