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Biomedical subjects

A Constantopoulos

Publications and source records attributed to A Constantopoulos.

At least 19 recordsLinked to original sources
PubMed2004

Etiology of community-acquired pneumonia in hospitalized school-age children: evidence for high prevalence of viral infections.

BACKGROUND: Community-acquired pneumonia (CAP) in young children is most commonly associated with viral infections; however, the role of viruses in CAP of school-age children is still inconclusive. METHODS: Seventy-five school-age children hospitalized with CAP were prospectively evaluated for the presence of viral and bacterial pathogens. Nasopharyngeal washes were examined by polymerase chain reaction for viruses and atypical bacteria. Antibody assays to detect bacterial pathogens in acute-phase and convalescent-phase serum samples were also performed. RESULTS: A viral infection was identified in 65% of cases. Rhinovirus RNA was detected in 45% of patients; infection with another virus occurred in 31%. The most common bacterial pathogen was Mycoplasma pneumoniae, which was diagnosed in 35% of cases. Chlamydia pneumoniae DNA was not detected in any patient; results of serological tests were positive in only 2 patients (3%). Mixed infections were documented in 35% of patients, and the majority were a viral-bacterial combination. CONCLUSIONS: The high prevalence of viral and mixed viral-bacterial infections supports the notion that the presence of a virus, acting either as a direct or an indirect pathogen, may be the rule rather than the exception in the development of CAP in school-age children requiring hospitalization.

Adolescent↗
PubMed2004

Invasive meningococcal disease presenting as Henoch-Schonlein purpura.

Henoch-Schonlein purpura (HSP) is an acute systemic form of vasculitis that has been associated with a number of viral and bacterial infections. Described here are the cases of two children with invasive meningococcal disease who presented with clinical and laboratory findings typical of HSP. Meningococcal infection may have been the trigger for the manifestation of HSP in these patients.

Bacteremia↗
PubMed2001

Is peptic ulcer a common cause of upper gastrointestinal symptoms?

UNLABELLED: The aim of the study was to investigate retrospectively a cohort of children with peptic ulcer disease during a period that covers the recent changes in diagnosis and management of the disease. Over a period of 9 years, 2550 children underwent upper gastrointestinal endoscopy for various reasons. All children, in whom a diagnosis of primary peptic ulcer was established, were included in the study. Previous and current medical history, family history, endoscopic and histological outcome were evaluated and the children were regularly followed-up on an out-patient basis. Primary peptic ulcer was diagnosed in 52 (10 gastric and 42 duodenal, 2%) out of 2550 children. The median age of children with gastric ulcer was 6.5 years, whereas of those with duodenal ulcer was 10.5 years (P=0.04). With regard to clinical symptoms no significant difference was found between children with and without ulcer. The prevalence of Helicobacter pylori infection was significantly higher in children with duodenal ulcer (62%) compared to those with gastric ulcer (20%; P < 0.001). At first follow-up visit, 1 month after the end of treatment, 19 symptomatic children underwent a repeat endoscopy, which showed ulcer healing in 95% and failure in H. pylori eradication in 27%. During the long-term follow-up (median 3.5 years), six children became symptomatic. Two of them had duodenal ulcer associated with positive H. pylori. CONCLUSION: Peptic ulcer disease is an uncommon disorder in childhood with non specific clinical features; it seems that efficient treatment and successful Helicobacter pylori eradication result in clinical improvement and cure as well as in long-term healing of ulcers.

Adolescent↗
PubMed2001

Analysis of Btk mutations in patients with X-linked agammaglobulinaemia (XLA) and determination of carrier status in normal female relatives: a nationwide study of Btk deficiency in Greece.

Bruton's tyrosine kinase (Btk) is a nonreceptor tyrosine kinase, critical for B-cell development and function. Mutations that inactivate this kinase were found in families with X-linked agammaglobulinaemia (XLA). In this study the Btk gene was analyzed in 13 registered Greek patients with XLA phenotype originated from 12 unrelated families, in order to provide a definite diagnosis of the XLA. The structure of Btk was analyzed at the cDNA level using the recently developed method, NIRCA (Non-Isotopic-Rnase-Cleavage-Assay). Alterations were detected in all patients and sequencing analysis confirmed the results and defined six novel XLA-associated Btk mutations (three missense mutations: C337G, L346R, L452P; one nonsense mutation: Y392X, and two frameshift alterations: c1211-1212delA, c1306-1307insA). Having defined the genetic alteration in the affected males of these families, the information was used to design polymerase chain reaction (PCR) primers and the Btk segments containing the mutated sequences were amplified from peripheral blood derived genomic DNA of potential female carriers. The PCR products were directly sequenced and carrier status was determined in 12 out of 16 phenotypically normal females analyzed. This protocol can be used once the nature of the Btk mutation has been defined in one of the affected males and provides a convenient, simple and reliable way to determine the carrier status of other female family members. Molecular genetic analysis constitutes a determinative tool for the definitive diagnosis of XLA and may allow accurate carrier and prenatal diagnosis for genetic counselling.

Adolescent↗
PubMed2000

Fiber intake and childhood appendicitis.

In order to investigate the possible role of fiber in the etiology of acute appendicitis, 203 consecutive appendectomized children with histologically proved appendicitis and 1922 controls were studied by the diet history method. Statistics were performed by multivariate analysis of variance, discriminant analysis and chi 2. Appendectomized children had statistically significant lower mean daily intake of fiber (17.4 g versus 20.4 g, P < 0.001) including all fiber fractions: cellulose, uronic acid, pentose, exose and lignin. No statistical difference was found for energy, protein, carbohydrate and fat intake. Discriminant analysis proved that only cellulose and exose are independently correlated to appendicitis and lower fiber intake is thought to be the cause in 70% of the cases. Recurrent abdominal pain, chronic constipation and positive family history of appendectomy were more frequent in appendectomized children (P < 0.001). This study gives evidence that low fiber intake could play an important role in the pathogenesis of appendicitis.

Abdominal Pain↗
PubMed1999

In vivo effect of sodium valproate on mouse liver.

The in vivo effect of sodium valproate (SV) on the activity of uridine diphosphate glucuronosyltransferase (UDP-GT) and hepatotoxicity in the mouse liver was studied. Mice were injected intraperitoneally (IP) with SV at doses varying from 50 to 800 mg/kg per day, for six consecutive days (dose-response group) or at a standard dose of 300 mg/g per day for 2-10 days (time-response group), whereas the controls were injected with normal saline. Valproic acid levels had a positive correlation to the dose (P < 0.001) and duration of drug administration (P = 0.006). A gradual increase in UDP-GT activity was observed in doses of up to approximately 400 mg/kg per day, whereas in higher doses the enzyme activity gradually decreased. The time course of UDP-GT activity at the standard dose of 300 mg/kg per day increased progressively, with a maximum up to the sixth day and then had a gradual reduction. Hepatic necrosis (which was unrelated to the dose or the duration of drug administration) was found in 13% of the SV-treated animals and in none of the controls. We conclude that at an optimal dose (300-400 mg/kg per day) and at a time course of 6 days, SV causes liver UDP-GT induction, whereas in higher doses and longer duration of administration, UDP-GT activity is gradually reduced. SV also causes hepatotoxicity unrelated to dose and time course.

Alanine Transaminase↗
PubMed1999

Upper gastrointestinal disease, Helicobacter pylori and recurrent abdominal pain.

Over a 5-y period, 396 children complaining of recurrent abdominal pain (RAP) underwent upper gastrointestinal endoscopy in order to identify any underlying organic pathology and determine the prevalence of Helicobacter pylori (H. pylori) infection. Histologically confirmed mucosal inflammation was found in 338 out of 396 children (85.4%); in 113 of 396 patients (28.5%), H. pylori was identified on the gastric mucosa. Significant discriminating factors between H. pylori positive and negative children with RAP included age (mean age for positive 11 y vs. 8.1 y for negative, p < 0.01) and gender (male gender predominance in the H. pylori positive, p < 0.001). No significant difference was found between H. pylori positive and negative groups regarding incidence and character of the presenting symptoms. All H. pylori positive children (100%) had abnormal histology compared with 225 out of 283 negative ones (79.5%). Histologically confirmed gastritis was the most prominent finding in H. pylori positive children compared with H. pylori negative (98.2% vs. 19%, p < 0.001). Conversely, oesophagitis was more common in H. pylori negative children (47.7% vs. 27.4%, p < 0.001). The incidence of peptic ulcer was higher in H. pylori infected patients than in the H. pylori negative group (5.3% vs. 1%, p < 0.05). Our data suggest that gastrointestinal pathology is more common than previously thought in children with RAP, while H. pylori infection is a relatively important factor in the etiology of upper gastrointestinal inflammation in RAP syndrome.

Abdominal Pain↗
PubMed1999

Diet and chronic constipation in children: the role of fiber.

BACKGROUND: Chronic constipation is one of the most common disorders in Western countries and despite numerous clinical, pathophysiologic, and epidemiologic studies its cause is still unclear. Several hypotheses have been proposed and according to experimental studies and clinical observation, fiber intake could play a role in its pathogenesis. The purpose of this case-control study was to examine the possible correlation of idiopathic chronic constipation in children and dietary intake, particularly fiber intake. METHODS: A randomized sample of children (291 children with constipation and 1602 controls) aged 2 to 14 years was taken from three of the 52 counties of Greece. Stratification was performed on the basis of urban, rural, or suburban location and socioeconomic status. The nutritional data were obtained from a 3-day dietary record and a dietary history. Statistical analysis was performed with multivariate tests, multivariate analysis of variance, discriminant analysis, and chi-square analysis according to the characteristics of the correlated variables. RESULTS: Constipated children had a lower caloric and nutrient intake (p < 0.001), lower body weight/height (p < 0.001), and higher prevalence of reported anorexia (p < 0.001). Discriminant analysis indicated that dietary fiber alone was independently negatively correlated with chronic constipation, despite the age and the age of onset of constipation. Relative risk also had a negative correlation with fiber intake (p < 0.001). Of the main fiber fractions only cellulose and pentose were independently correlated with chronic constipation. CONCLUSIONS: Lack of fiber may play an important role in the etiology of chronic idiopathic constipation in children.

Adolescent↗
PubMed1998

Herpes zoster in children.

BACKGROUND: The clinical studies of series of children with herpes zoster (HZ) are rather limited. OBJECTIVE: The purpose of this study was to evaluate the epidemiologic conditions, clinical manifestations, therapy, and outcome of HZ in children. METHODS: Twenty-one patients with HZ have been studied. Five patients who had herpes simplex virus infection were excluded. The laboratory diagnosis was made by fluorescent techniques. Acyclovir was administered systematically for 2 more days after no new lesions had developed. RESULTS: Thirteen patients (group A) were immunocompromised; eight patients (group B) were otherwise healthy. Two patients from group B had intrauterine varicella; the other six patients had had varicella under the age of 4 years. Three patients were recently exposed to varicella. The duration of HZ was significantly longer in group A than in group B, but the outcome was good in all patients. CONCLUSION: Herpes simplex virus infection may simulate the pattern of HZ; varicella in early childhood is a risk factor for HZ in otherwise healthy children; exposure of a child to varicella may cause reactivation of latent HZ virus; and acyclovir therapy within 3 days of exanthem onset prevents significant morbidity and death in immunocompromised children with HZ.

Acyclovir↗
PubMed1998

Elevated serum prolactin concentrations in phenylketonuric patients on a 'loose diet'.

OBJECTIVE: High levels of phenylalanine (Phe) have been shown to reduce dopamine (DA) and noradrenaline (NA) production. We have therefore evaluated whether increased serum Phe concentrations lead to increased prolactin (PRL) secretion in phenylketonuria. PATIENTS: Forty-two patients with classical phenylketonuria were divided into two groups. Group A (n = 19) adhered very strictly to their special diet (Phe = 0.09 +/- 0.039 mmol/l) and Group B (n = 23) were on a 'loose diet' (Phe = 0.77 +/- 0.45 mmol/l). Thirty healthy children of comparable age served as controls. MEASUREMENTS: PRL was measured by RIA, and Phe and tyrosine (Tyr) with an amino-acid autoanalyser. Adrenaline (A), noradrenaline (NA), and dopamine (DA) were measured by HPLC. RESULTS: Serum PRL in group B patients (1595 +/- 57 mU/l) was significantly raised compared to Group A patients (243 +/- 57 mU/l) and controls (201 +/- 55 mU/l) (P < 0.001). Serum DA, A and NA in group B were lower than in group A patients and controls. Serum Phe in group B patients was significantly correlated to serum PRL (r = 0.59) and DA (r = -0.41). Irregular menses were observed in 1/10 women from group A but in 10/13 in group B. CONCLUSION: High serum phenylalanine concentrations in phenylketonuric patients not strictly adhering to their diets are correlated with high serum PRL and low serum dopamine concentrations, and a high prevalence of menstrual irregularities.

Adolescent↗
PubMed1998

Juvenile chronic arthritis profile in Greek children.

BACKGROUND: Juvenile chronic arthritis (JCA) is the commonest autoimmune rheumatic disease in childhood and presents different clinical subtypes. Juvenile chronic arthritis is considered to be of a polygenic nature and its genetic background is still under investigation. The clinical profile of JCA in the Greek population has not been studied completely. This study retrospectively analyzed the clinical and immunological features of JCA in Greek children presented between 1989 and 1994. Human leukocyte antigen (HLA)-positive or -negative associations in the different clinical subtypes were also detected. The findings of this study were correlated with those reported from other populations. METHODS AND RESULTS: Antinuclear antibodies (ANA) anti-ds DNA and anti-extractable nuclear antigen antibodies were estimated by immunofluorescent and ELISA assays. Human leukocyte antigen typing was performed by microlymphocytotoxicity, using immunobeads. The peak ages of JCA onset were between 2 and 5 years and also between 9 and 12 years. There was a high female predominance in pauciarticular and polyarticular groups. The most common disease was pauciarticular (58.7%) followed by systemic (25%) arthritis. The incidence of eye involvement was 12.5% and presented only in the pauciarticular group. Overall, ANA positivity was 53.7%, increasing to 90% in pauciarticular cases associated with chronic uveitis. In the early onset (EOPA) pauciarticular subtype, positive-HLA associations with alleles DR11 and DR8 were shown. In the late onset pauciarticular (LOPA) group only B27 allele was increased. CONCLUSIONS: The results of this retrospective study did not reveal major differences between JCA in Greek children compared with other Caucasian series.

Adolescent↗
PubMed1995

Increased beta-endorphin but not Leu-enkephalin in plasma due to preoperative stress.

The levels of beta-endorphin and Leu-enkephalin were measured in the plasma of 23 children (16 male, 7 female) who were admitted to the Children's Hospital for elective (non-emergency) surgery, adenoidectomy and/or tonsillectomy. Two blood samples were obtained preoperatively. The first sample was taken during admission to the hospital; the second on 24 h later and just 5 min before the operation, without pre-medication or narcosis. beta-endorphin and Leu-enkephalin levels were measured using a RIA method after solid phase extraction of the samples. Mean beta-endorphin concentrations during admission to the hospital were 11.77 +/- 9.36 pg/ml. Twenty four hours later, and just 5 min before surgery, the mean levels of beta-endorphin were increased to 27.45 +/- 16.66 pg/ml. A statistically significant increase (t-value = -5.42) was found for beta-endorphin levels 5 min before the operation compared with 24 h earlier (2-tail probability p < 0.0001). The Wilcoxon matched-pairs signed-ranks-test also showed p < 0.0001 (Z = -4.197). In contrast, Leu-enkephalin levels remained unchanged. The mean values were 11.44 +/- 1.49 pg/ml on the day of admission, and 12.11 +/- 2.08 pg/ml 5 min before the operation. We did not find statistically significant differences between the paired samples (t-value = -1.53, 2-tail probability p = 0.139). The increase in beta-endorphin could be the result of preoperative anxiety about the narcosis and surgery.

Adolescent↗
PubMed1994

Seasonal variation of neonatal and infant deaths by cause in Greece.

The seasonal variation of neonatal and infant deaths in Greece was analyzed for nine consecutive years (1979-1987) by cause of death, age of death and urbanization of permanent residence. Data were supplied by the National Statistical Service of Greece. Statistical analysis was done using the Edward's method. The seasonal patterns of the number of deaths and death rates were similar. Neonatal deaths in total did not show significant seasonality but postneonatal deaths showed seasonal variation with a peak in the winter, more evident in rural areas. Neonatal deaths from prematurity showed statistically significant seasonal variation with a peak in May. Postneonatal deaths from infections and mainly those from pneumonia showed very significant seasonal variation with a peak in February that was more prominent in rural areas. Seasonal pattern with peak in late winter was also found for postneonatal deaths from injuries. The seasonal patterns for neonatal and postneonatal deaths from sudden infant death syndrome were suggestive of an increased occurrence during the winter months mainly in urban areas.

Age Factors↗