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Biomedical subjects

S Caglayan

Publications and source records attributed to S Caglayan.

At least 19 recordsLinked to original sources

Plasma melatonin concentration before and during testosterone replacement in Klinefelter's syndrome: relation to hepatic indolamine metabolism and sympathoadrenal activity.

The mechanisms leading to alterations in plasma melatonin (MT) levels with testosterone replacement in Klinefelter's syndrome (KS) remain elusive. We investigated early morning plasma MT levels, urinary 6-sulfatoxymelatonin (6-SM) levels, and urinary catecholamine levels before and 6 months after testosterone treatment in 31 patients with KS and 20 healthy males to demonstrate whether alterations in plasma MT levels in such patients are due to subtle changes in sympathoadrenal activity and/or alterations in the hepatic indolamine metabolism influenced by testosterone replacement. The plasma MT level was measured by RIA. The sensitivity of the test was 10.7 pmol/L. The 6-SM level was measured by enzyme-linked immunosorbent assay. Urinary catecholamines were determined by high performance liquid chromatography. The pretreatment mean plasma MT level was insignificantly higher in the patient group than in the control group (72.57 +/- 74.82 vs. 42.37 +/- 29.02 pmol/L; z = -1.218; P = 0.223). The pretreatment urinary 6-SM and norepinephrine (NE) levels were significantly lower and, the epinephrine (E) and dopamine levels were insignificantly lower in the patient group than those in the control group [6-SM, 76.54 +/- 31.92 vs. 125.49 +/- 50.16 nmol/L (z = -3.727; P < 0.001); NE, 120.79 +/- 58.33 vs. 178.84 +/- 81.61 nmol/day (z = -2.585; P = 0.01); E, 31.27 +/- 27.42 vs. 34.65 +/- 28.33 nmol/day (z = -0.39; P: = 0.692); dopamine, 1577.02 +/- 863.02 vs. 1812.32 +/- 677.59 nmol/day (z = -1.03, P = 0.308)]. After testosterone replacement, plasma MT levels were significantly decreased (72.57 +/- 74.82 vs. 24.73 +/- 23.61 pmol/L; z = -4.29; P < 0.001), and urinary 6-SM, NE, E, and dopamine levels were significantly increased [6-SM, 25.04 +/- 10.44 vs. 40.05 +/- 17.65 ng/mL (z = -4.78; P < 0.001); NE, 120.78 +/- 58.33 vs. 154.08 +/- 61.35 nmol/day (z = -4.27; P < 0.001); E, 31.27 +/- 27.42 vs. 40.74 +/- 30.04 nmol/day (z = -4.22; P < 0.001); dopamine, 1577.02 +/- 863.02 vs. 2162.67 +/- 823.15 (z = -6.127; P < 0.001)]. There was no relation between plasma MT levels, urinary 6-SM, and catecholamine levels and levels of gonadotropins or gonadal steroids either before or after treatment. We demonstrate that in untreated KS, plasma MT levels tend to be higher than those in normal controls, whereas those of the melatonin metabolite 6-SM and those of NE in urine tend to be lower. After testosterone treatment, however, plasma MT levels fall significantly, whereas urinary levels of 6-SM and NE rise. Our data show that the effect of testosterone is mediated by enhanced metabolism of melatonin, not by any effect on net sympathetic outflow, and that the increase in plasma melatonin in untreated KS patients also results from an alteration in the rate of melatonin metabolism and not from increased net sympathetic activity.

Adrenal Glands↗

Synchronicity of frequently sampled thyrotropin (TSH) and leptin concentrations in healthy adults and leptin-deficient subjects: evidence for possible partial TSH regulation by leptin in humans.

Leptin signals the status of energy reserves to the brain. Leptin stimulates biosynthesis of TRH in vitro and influences the activity of the hypothalamic-pituitary-thyroid axis in vivo in rodents. Because blood levels of both leptin and TSH display diurnal variation with a distinct nocturnal rise, we sought to determine whether a relationship exists between fluctuations in circulating leptin and TSH. We measured serum leptin and TSH levels every 7 min for 24 h in five healthy men and found that both leptin and TSH levels are highly organized and pulsatile. A similar pattern of leptin and TSH rhythms was observed, with TSH and leptin levels reaching a nadir in late morning and a peak in the early morning hours. Importantly, cosinor analysis on the absolute leptin and TSH levels revealed a statistically significant fit for a 24-h period and the two hormones showed similar probabilities of rhythm and superimposable peak values. Furthermore, this study shows a strong positive Pearson correlation between the 24-h patterns of variability of leptin and TSH in healthy subjects. Finally, the ultradian fluctuations in leptin levels showed pattern synchrony with those of TSH as determined by cross-correlation analysis, by cross-approximate enthropy and Bayessian analysis applied independently. To further explore whether these associations could reflect an underlying regulation of TSH secretion by leptin, we also studied frequently sampled leptin and TSH levels in four brothers, members of a family with leptin deficiency (one normal homozygote, two heterozygotes, and one leptin-deficient homozygote). Leptin levels of the homozygous leptin-deficient subject are detectable but bioinactive, and the rhythm of his TSH is disorganized. 24-h pattern of leptin and TSH variability in the heterozygous subjects, although significantly correlated, showed a weaker correlation compared with the strong correlation in the normal subjects. These data are consistent with the possibility that leptin may regulate TSH pulsatility and circadian rhythmicity, but interventional studies are needed to definitively prove whether leptin regulates the minute-to-minute oscillations and ultradian rhythm of TSH levels.

Adult↗

Plasma concentrations of granulocyte-macrophage colony-stimulating factor and interleukin-6 in septic and healthy preterms.

UNLABELLED: Plasma granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-6 (IL-6) concentrations were determined in 21 preterm infants with sepsis and nine healthy preterm neonates of the same postnatal age at sampling. Plasma GM-CSF levels were elevated at diagnosis in the septic preterms as compared to the healthy preterms (P = 0.01), but did not differ significantly on recovery. IL-6 levels were also elevated markedly at diagnosis (P = 0.0003), but decreased to normal on recovery as compared to the healthy preterm infants. GM-CSF levels were more prominent in septic preterms with neutropenia than those of non-neutropenic infants (P = 0.03). CONCLUSION: Preterm infants can produce high levels of granulocyte-macrophage colony-stimulating factor and interleukin-6 in response to bacterial sepsis.

Granulocyte-Macrophage Colony-Stimulating Factor↗

Increased gastric production of platelet-activating factor, leukotriene-B4, and tumor necrosis factor-alpha in children with Helicobacter pylori infection.

The concentrations of platelet-activating factor (PAF), leukotriene-B4 (LTB4), and tumour necrosis factor-alpha (TNF-alpha) in homogenate supernatants of gastric mucosal biopsy specimens and in gastric juice from Helicobacter pylori-positive (N = 21) and -negative children (N = 14) were investigated in order to determine whether these lipid mediators and the cytokine are involved in the inflammatory reaction of H. pylori-associated gastritis. PAF and LTB4 concentrations were measured after high-performance liquid chromatography (HPLC) purification by specific radioimmunoassay, and TNF-alpha concentrations were determined by using an enzyme-linked immunosorbent assay. The concentrations of PAF, LTB4, and TNF-alpha measured in gastric juice and biopsy homogenate supernatants of children with H. pylori-positive gastritis were found to be statistically elevated and in positive correlation with each other. This study suggested that increased local mucosal production of potent proinflammatory agents such as PAF, LTB4, and TNF-alpha may be implicated in the pathogenesis of H. pylori-associated gastritis in childhood.

Case-Control Studies↗

Rubella seroprevalence in an unvaccinated population in Izmir: recommendations for rubella vaccination in Turkey.

BACKGROUND: The European Advisory Group on the Expanded Program on Immunization of WHO has recommended that by 2010 or earlier congenital rubella should be well-controlled or eliminated in all countries in Europe. Debate on the introduction of rubella vaccine into national immunization schedules continues to occur, and data on rubella and congenital rubella syndrome in Turkey are insufficient. OBJECTIVE: To determine age-specific rubella seroprevalence in the 1- to 29-year-old unvaccinated population in Izmir, Turkey. METHODS: A total of 600 unvaccinated persons 1 to 29 years old were selected for the study with cluster sampling in Izmir, Turkey. The information on sociodemographic characteristics and disease history was gathered for each participant, and in 580 of them rubella-specific IgG antibodies were assayed quantitatively by the micro-enzyme immunoassay. RESULTS: Of the 580 participants tested for rubella antibodies, 135 (23.3%) were seronegative. The proportions of susceptible individuals were 61.7, 29.5, 12.4, 10.3 and 8.4% in the age groups of 1 to 4, 5 to 9, 10 to 14, 15 to 19 and 20 to 29 years, respectively. Of the young women 15 to 19 years of age, 13.5% were susceptible to rubella infection. CONCLUSIONS: Because a substantial proportion of women in their childbearing years are susceptible to rubella, immunization efforts should be directed at infants or prepubertal children.

Adolescent↗

Study of pro-inflammatory (TNF-alpha, IL-1alpha, IL-6) and T-cell-derived (IL-2, IL-4) cytokines in plasma and synovial fluid of patients with juvenile chronic arthritis: correlations with clinical and laboratory parameters.

Acute phase proteins, synovial fluid (SF) cellular infiltrates, pro-inflammatory (TNF-alpha, IL-1alpha, IL-6) and Th1 (IL-2) and Th2 (IL-4) derived cytokine levels both in plasma and SF were examined in pauciarticular and polyarticular juvenile chronic arthritis (JCA) patients during the active (n = 22) and inactive (n = 14) period in order to determine pathogenic mechanisms and correlations between cytokines and laboratory parameters showing disease activity. The erythrocyte sedimentation rate (ESR), serum C-reactive protein (CRP) and IgG concentrations were found to be significantly elevated in the active period of JCA. In pauciarticular JCA patients, when compared with their peripheral blood lymphocyte subpopulations, SF CD3+ cells (73.1%) and HLA-DR+ active T cells (22.5%) were found to be significantly increased. In the active period of JCA, plasma TNF-alpha and IL-6 concentrations were significantly elevated. Plasma IL-2 and IL-4 levels were not elevated and were found to be similar to those in the inactive phase and in healthy controls. SF IL-6, TNF-alpha and IL-1alpha levels were extremely high in all the patients. SF IL-4 and IL-2 levels were all undetectable. There was a significant correlation between ESR values and plasma IL-6 levels and between serum CRP levels and plasma IL-6 and TNF-alpha concentrations. In conclusion, increased local production of pro-inflammatory cytokines appears to account for the articular manifestations of JCA. The impaired production of anti-inflammatory Th2-derived cytokines (IL-4) seems to cause increased production of inflammatory cytokines acting on the balance between them. The deficit in IL-2 production was not suggested to be primarily involved in the pathogenesis. In addition, not only CRP and ESR values, but also plasma IL-6 and TNF-alpha concentrations may be used as markers of disease activity.

Adolescent↗

Effects of gonadotropin and testosterone treatments on plasma leptin levels in male patients with idiopathic hypogonadotropic hypogonadism and Klinefelter's syndrome.

Since little is known about the effects of gonadotropin and testosterone treatment on leptin levels in male hypogonadism, we determined fasting plasma leptin levels before and 3 months after treatment in 21 patients with idiopathic hypogonadotropic hypogonadism (IHH), 16 patients with Klinefelter's syndrome and 20 male controls. Patients with IHH were treated with hCG/human menopausal gonadotropin, whereas patients with Klinefelter's syndrome received T treatment. Plasma leptin levels were measured by an RIA with a sensitivity of 0.5 microg/L. Mean leptin levels in patients with IHH before treatment (9.23+/-4.09 microg/L) were not significantly different from those in patients with Klinefelter's syndrome (7.29+/-5.05 microg/L; z=-1.41; P=0.15). Leptin levels in both IHH and Klinefelter's syndrome groups were, however, significantly higher than in the normal men (3.91+/-1.67 microg/L) (P<0.001 and P<0.01, respectively). Mean leptin levels did not change significantly 3 months after the initiation of gonadotropin (11.6+/-6.44 microg/L) or T (8.32+/-5.17 microg/L) treatment in either IHH or Klinefelter's syndrome. Our study demonstrated that mean plasma leptin levels are not influenced by short-term gonadotropin or T treatment in male hypogonadism.

Adult↗

Salivary and gastric fluid secretory immunoglobulin A and free secretory component concentrations in children with Helicobacter pylori-positive gastritis.

The concentrations of secretory IgA (sIgA) in the saliva and the concentrations of free secretory components (FSC) both in the saliva and gastric fluid of patients with Helicobacter pylori HP-positive gastritis and of a control group with functional recurrent abdominal pain (RAP) were measured in order to determine whether there is a deficiency of these non-specific local defence factors in children with HP infection. Eighteen patients with HP-positive gastritis and 12 children with RAP were included in the study and sIgA and FSC concentrations were analysed using the radial immunodiffusion technique. In contrast to our initial hypothesis, the concentrations of FSC in saliva and gastric fluid and sIgA in saliva of patients with HP infection showed no significant difference when compared with children who do not have an organic disease and HP infection. It is suggested that these local defence factors are not involved in the pathogenesis of HP-positive gastritis.

Abdominal Pain↗

Seasonal benzathine penicillin G prophylaxis for recurrent streptococcal pharyngitis in children.

BACKGROUND: To assess the efficacy of benzathine penicillin G (BPG) prophylaxis in recurrent streptococcal pharyngitis in children. METHODS: One hundred and sixty children, aged 4-11 years, who experienced at least two episodes of group A beta-hemolytic streptococcal (GABHS) pharyngitis during a 4-month observation period between September and December 1995 were randomly divided into two groups. During the following 4-month period between January and April 1996, 80 children received BPG prophylaxis every 3 weeks as a single intramuscular injection of 1.2 million units for a body weight greater than 27 kg and a half dose for 27 kg or less. Eighty children were accepted as a control group and were not given BPG prophylaxis. RESULTS: The children in the BPG group experienced significantly less GABHS pharyngitis than those in the control group during the second 4-month period (16 vs 244 episodes, respectively, P < 0.001). BPG prophylaxis decreased streptococcal pharyngitis by 92% in the children in the study group, while the frequency of GABHS pharyngitis was unchanged in those in the control group during the second 4-month period compared with the first 4-month period. CONCLUSIONS: The data in the present study demonstrated that intramuscular BPG prophylaxis is very effective in preventing GABHS pharyngitis in children. It is recommended that it is used every 3 weeks in at least the fall-winter seasons in children susceptible to frequent GABHS pharyngitis.

Antibiotic Prophylaxis↗

Plasma and synovial fluid soluble CD23 concentrations in children with juvenile chronic arthritis.

Since increased levels of sCD23 were demonstrated in patients with autoimmune diseases, plasma and synovial fluid sCD23 levels were examined in 22 patients with juvenile chronic arthritis (JCA) and in 10 children undergoing arthrocentesis for orthopedic disorders. There was no significant difference in plasma sCD23 concentrations between patients with pauciarticular and polyarticular onset. Plasma and synovial fluid sCD23 concentrations were found to be significantly increased in JCA patients as compared to controls. However, plasma sCD23 levels were not positively correlated with laboratory parameters showing disease activity such as erythrocyte sedimentation rate, C-reactive protein, serum IgG and IgA. It was concluded that increased production of sCD23 in peripheral blood and synovial fluid might be important in the pathogenesis of JCA. However, determination of this immunological parameter provides no useful clinical information about disease activity and management.

Adolescent↗

Plasma interleukin-3 (IL-3) and IL-7 concentrations in children with homozygous beta-thalassemia.

Plasma levels of IL-3 and IL-7 were studied in 23 patients with homozygous beta-thalassemia in order to determine whether these cytokines are involved in abnormalities in erythropoiesis and immune responses as observed in thalassemic patients. No significant difference was found in plasma IL-7 concentrations between thalassemic patients and healthy controls and it was suggested that IL-7 is not a cytokine involved in cellular immunological alterations in beta-thalassemia. However, the number of thalassemic patients with detectable IL-3 concentrations was significantly higher. It was concluded that IL-3 production has to be studied in detail in order to learn more about the involvement of this cytokine in erythropoiesis of thalassemic patients.

Adolescent↗

Is the frequency of Robinow syndrome relatively high in Turkey? Four more case reports.

We describe the clinical features of Robinow syndrome in the children of four Turkish couples. All the patients had cardinal features of this condition, such as short stature, frontal bossing, hypertelorism, short upturned nose with anteverted nares, micrognathia, mesomelic shortening of the forearms, vertebral and costal anomalies and hypoplastic genitalia. In contrast to reports in the literature, one patient showed extensive webbing of the toes and epigastric hernia. Parental consanguinity was present in two of the four cases. To our knowledge, at least 80 cases have been reported in the literature to date, including 19 cases born to Turkish couples in addition to our four cases. The evidence suggests that the frequency of Robinow syndrome is relatively higher in Turkey than in other areas of the world.

Abnormalities, Multiple↗

Aflatoxin: is it a neglected threat for formula-fed infants?

In the present study, the risk of exposure to aflatoxin in infants fed breast milk and formula was investigated. For this purpose, aflatoxin B1 (AFB1) was determined in the serum of both breast-fed and formula-fed infants. Serum AFB1 positivity was significantly higher in the formula-feeding (F) group than the breast-feeding (B) group (42.8 vs 8.5%, P < 0.01). The AFB1 concentration in different commercial formulas was also determined. Aflatoxin B1 was found in seven of the eight newly opened packages of different brands of formula. The concentrations showed a statistically significant increase at the 30th day after opening the packages (P < 0.01). Although AFB1 concentrations in the formulas were found to be within acceptable limits for most countries, still, its existence must be carefully evaluated because future influences of very small amounts of aflatoxin on the growing organism have not been fully elucidated. Therefore, it was again concluded that for infants, human milk is safer than commercial formulas because of the lower contamination risk of aflatoxin. Also, commercial formulas must be regularly examined by authorities for the possible risk of aflatoxin contamination.

Aflatoxin B1↗

Increased mucosal inflammatory cytokines in children with Helicobacter pylori-associated gastritis.

The concentrations of tumour necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6) and IL-1-beta in tissue homogenates of gastric mucosal biopsy specimens, and in gastric juice samples from Helicobacter pylori-positive and -negative children, were determined. The study population comprised 30 children with recurrent abdominal pain attending upper gastrointestinal endoscopy. Of these patients 18 were infected with H. pylori. Cytokine concentrations in gastric biopsy homogenate supernatants and in gastric juice were measured by enzyme-linked immunosorbent assay (ELISA). TNF-alpha levels in gastric juice and in gastric biopsy homogenate supernatants in patients with H. pylori-positive gastritis were found to be significantly higher than those in children without H. pylori infection. IL-6 levels were also higher in H. pylori-infected subjects, but the difference in IL-6 concentrations measured in gastric juice and biopsy homogenate supernatants did not reach statistical significance. IL-1-beta concentrations in both specimens showed no significant difference between the two groups of children. It was suggested that increased levels of inflammatory cytokines, especially TNF-alpha and IL-6 generated locally within the gastric mucosa might be implicated in the pathogenesis of H. pylori-associated gastritis in childhood.

Abdominal Pain↗