Pulmonary arterial hypertension in the pediatric age

Pulmonary hypertension is defined as a mean pulmonary artery pressure more than 25 mmHg at rest or 30 mmHg on exercise. Pathogenesis of pulmonary hypertension is recognized to be multifactorial: vasoconstriction, proliferation, inflammation, and thrombosis. The main point in the clinical management is to assess the potential causes, the degree of functional and hemodynamic impairment and the available therapeutic options. Treatment of children with idiopathic pulmonary hypertension is similar to that of adults, but the results are often difficult to predict, with clinical deterioration being very rapid in early symptomatic patients. However, the availability of chronic vasodilator therapy, in particular epoprostenol, has led to a significant improvement in survival of children with idiopathic pulmonary hypertension and oral vasodilator agents are currently being evaluated. Moreover, lung transplantation is, nowadays, a reality even in children. Survival for patients with idiopathic pulmonary hypertension undergoing lung transplantation is approximately 65% at 1 year and 45% at 5 years. Accepted indications are severe clinical deterioration (New York Heart Association class III or IV) despite available medical treatments including intravenous epoprostenol. Timing for listing the patient is a difficult issue that should take into account possible markers of poor prognosis on medical therapy together with mortality rate of lung transplantation, local organ availability and mean waiting time on the list before transplantation.

Different types of cardiomyopathy associated with isolated ventricular noncompaction

Although mainly described in the context of dilated and hypokinetic left ventricles, it is unclear whether isolated ventricular noncompaction (IVNC) is a distinct cardiomyopathy, a subtype of dilated cardiomyopathy, or a morphogenetic disorder. To investigate the spectrum of cardiomyopathies associated with IVNC, children and adults with stringent echocardiographic diagnoses of IVNC were reviewed. Seventy-three patients (12 children aged <15 years) seen since 1994 satisfied stringent echocardiographic criteria for IVNC. Sixty-five patients (89%; 11 children) had dilated cardiomyopathy, 2 adults had clear-cut hypertrophic cardiomyopathy, 1 adult had restrictive cardiomyopathy (to the investigators' knowledge, the first reported example of this particular association), and 5 patients (1 child) had normal left ventricular morphology and function. In conclusion, knowledge that IVNC can co-exist with restrictive and hypertrophic cardiomyopathy (in addition to the dilated form) supports the concept that IVNC is a morphologic trait rather than a distinct cardiomyopathy. This knowledge should be taken into account during echocardiographic examination and encourage the use of contrast echocardiography (and magnetic resonance) and could also orient molecular biology studies.

Double orifice tricuspid valve in an infant with tetralogy of Fallot

Atrioventricular valve duplication, also known as double orifice valve, is an excitingly rare anomaly that can involve either the mitral or more uncommonly the tricuspid valve. Herein we describe a case of a double orifice tricuspid valve that prejudiced the complete repair in a symptomatic infant with tetralogy of Fallot.

On the importance of anandamide structural features for its interactions with DPPC bilayers: effects on PLA2 activity

The acylethanolamide anandamide (AEA) occurs in a variety of mammalian tissues and, as a result of its action on cannabinoid receptors, exhibits several cannabimimetic activities. Moreover, some of its effects are mediated through interaction with an ion channel-type vanilloid receptor. However, the chemical features of AEA suggest that some of its biological effects could be related to physical interactions with the lipidic part of the membrane. The present work studies the effect of AEA-induced structural modifications of the dipalmitoylphosphatidylcholine (DPPC) bilayer on phospholipase A2 (PLA2) activity, which is strictly dependent on lipid bilayer features. This study, performed by 2-dimethylamino-(6-lauroyl)-naphthalene fluorescence, demonstrates that the effect of AEA on PLA2 activity is concentration-dependent. In fact, at low AEA/DPPC molar ratios (from R = 0.001 to R = 0.04), there is an increase of the enzymatic activity, which is completely inhibited for R = 0.1. X-ray diffraction data indicate that the AEA affects DPPC membrane structural properties in a concentration-dependent manner. Because the biphasic effect of increasing AEA concentrations on PLA2 activity is related to the induced modifications of membrane bilayer structural properties, we suggest that AEA-phospholipid interactions may be important to produce, at least in part, some of the similarly biphasic responses of some physiological activities to increasing concentrations of AEA.

Growth and adult height in atypical coeliac patients, with or without growth hormone deficiency

OBJECTIVE

To evaluate the effect of a gluten-free diet on growth and adult height, when available, in coeliac children without gastrointestinal symptoms.

PATIENTS AND METHODS

Sixty-one coeliac children without gastro-intestinal symptoms were included in the study. The age at diagnosis was 9.50 +/- 3.3 years. Thirty-eight had short stature at diagnosis (< 10th percentile) and 23 had normal stature. Thirty-seven reached adult height.

RESULTS

After beginning the diet an increase in growth velocity was seen in 30 patients (responders) (20 with initial short stature), while in 31 patients (18 with short stature) there was no catch-up growth (non-responders). Bone age at diagnosis was significantly more delayed in the responders than in the non-responders. Target height was significantly higher in children with normal stature at diagnosis than those with short stature. Growth hormone (GH) deficiency was found and confirmed after 6-12 months of diet in 12 of the 38 patients (32%) with short stature. In the group of the 30 'short' patients who attained final height, target height was attained or improved in 12 patients (40%): in eight of the 16 (50%) responders and in four of the 14 (29%) non-responders; in eight (all responders) out of 22 (36%) without GH deficiency, and in four out of eight (50%) patients with GH deficiency treated with GH (all non-responders).

CONCLUSIONS

In children in whom coeliac disease is diagnosed because of short stature, a gluten-free diet will be successful if at diagnosis there is a delay of bone age and in the first year of diet there is an evident catch-up growth. When this does not occur, i.e. in half of the patients (18 out of 38), it may be because of an associated and transient GH deficiency. In these patients a period of GH replacement therapy as well as a gluten-free diet may improve their final height.

Lung function in children with diabetes mellitus

A cross-sectional study design was undertaken to assess pulmonary function in children with insulin-dependent diabetes mellitus (IDDM), and to establish if there is any relationship with diabetic factors and complications. Thirty-eight children (10 +/- 1.8 years) with IDDM and without clinical or radiological evidence of lung involvement, and 41 healthy age-matched reference subjects, underwent a pulmonary function study. Thirteen (34%) of 38 subjects with IDDM were studied at the onset of their disease. Adjusted values expressed as SD score of forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV(1)), and the transfer factor for carbon monoxide (TLCO) were found to be significantly lower than in controls (-0.54 +/- 0.87 vs. 0.40 +/- 1.10, P = 0.0008; -0.11 +/- 0.96 vs. 0.52 +/- 1.07, P = 0.01; -1.60 +/- 1.07 vs. -0.57 +/- 1.28, P = 0.001, respectively). These differences also existed in the group investigated at onset of diabetes. Residual volume (RV) and RV/total lung capacity ratio (RV/TLC) were significantly higher in the whole group of patients with IDDM than in controls (-0.20 +/- 0.83 vs. -0.80 +/- 0.88, P = 0.003; and 26 +/- 6.2 vs. 21 +/- 5.0, P = 0.0002, respectively). Seventeen patients (45%) had abnormal pulmonary function (SD score, less than -1.64): 16 subjects had reduced TLCO, 4 had reduced FVC, and in 3 of the 17, both functional indices were abnormal. There was no significant relationship between pulmonary function indices and diabetic factors or complications. The only significant association was between abnormal TLCO and females (P = 0.03), suggesting that sex may be a predisposing factor for the development of pulmonary complications. This study supports the view that the lung is functionally involved in children with IDDM early on in the course of the disease.

Identification of eight novel glucokinase mutations in Italian children with maturity-onset diabetes of the young

Maturity-onset diabetes of the young (MODY) is a clinically heterogeneous group of disorders characterized by early onset non-insulin-dependent diabetes mellitus, autosomal dominant inheritance, and primary defect in the function of the beta cells of the pancreas. Mutations in the glucokinase (GCK) gene account for 8%-56% of MODY, with the highest prevalences being found in the southern Europe. While screening for GCK mutations in 28 MODY families of Italian origin, we identified 17 different mutations (corresponding to 61% prevalence), including eight previously undescribed ones. The novel sequence variants included five missense mutations (p.Lys161Asn c.483G>C in exon 4, p.Phe171Leu c.511T>C in exon 5 and p.Thr228Ala c.682A>G, p.Thr228Arg c.683C>G, p.Gly258Cys c.772G>T in exon 7), one nonsense mutation (p.Ser383Ter c.1148C>A in exon 9), the splice site variant c.1253+1G>T in intron 9, and the deletion of 12 nucleotides in exon 10 (p.Ser433_Ile436del c.1298_1309del12). Our study indicates that mutations in the GCK/MODY2 gene are a very common cause of MODY in the Italian population and broadens our knowledge of the naturally occurring GCK mutation repertoire.

The severity of clinical presentation of type 1 diabetes in children does not significantly influence the pattern of residual beta-cell function and long-term metabolic control

AIM

The purpose of the present study was to compare relationships between the clinical presentation of type 1 diabetes in children and residual beta-cell secretion and long-term metabolic control.

METHODS

This retrospective study was conducted in 66 diabetic children with age at diagnosis ranging from 0.7 to 14.8 yr. The patients showed contrasting characteristics at diagnosis: either diabetic ketoacidosis (DKA) (group 1, n = 29) or absence of metabolic derangement (group 2, n = 37) associated with marked (group 2A, n = 12) or mild hyperglycemia (group 2B, n = 25). A regular follow-up was available for at least 10 yr (10-32 yr) in all cases and for 20 yr in 23 cases. C-peptide levels were measured from diagnosis and thereafter at intervals for the first years of disease until becoming permanently undetectable.

RESULTS

C-peptide levels at diagnosis were undetectable in about 20% of the cases both with and without DKA. C-peptide levels at diagnosis, the duration of measurable C-peptide levels and the maximum value found during follow-up were not significantly different in the three groups and were not correlated with glycated hemoglobin (GHb) calculated throughout the whole period. No differences were found between the groups of patients concerning GHb values and insulin dose at 10, 15 and 20 yr of disease. The patients of group 2A, characterized by an extremely high glycemic level without ketoacidosis, had a significantly higher prevalence of HLA DR3/4 heterozygosity.

CONCLUSIONS

The severity of clinical presentation at diagnosis does not significantly influence residual beta-cell function, and long-term metabolic control.

The glucose area under the profiles obtained with continuous glucose monitoring system relationships with HbA(lc) in pediatric type 1 diabetic patients

OBJECTIVE

The purpose of this study was to determine whether the continuous glucose monitoring system (CGMS) (MiniMed, Sylmar, CA) 1) is sufficiently representative of the overall metabolic control as assessed by HbA(1c), 2) could be used to identify a particular blood glucose threshold value affecting hemoglobin glycation; and 3) is able to show any relationship between particular glycemic profiles and HbA(1c) levels.

RESEARCH DESIGN AND METHODS

Of 44 pediatric patients with type 1 diabetes who wore CGMS devices, 28 subjects were selected for the study. Criteria for inclusion were high levels of HbA(1c) (> or =8%) for more than 1 year or a history of frequent hypoglycemic episodes and a complete CGMS registration for 72 h. Age of the subjects ranged from 5.7 to 24.8 years, the mean duration of disease was 7.63 +/- 4.75 years, and the mean HbA(1c) value was 8.7 +/- 1.3%. CGMS data were downloaded and glucose profiles were analyzed. The area under each glucose profile was calculated by means of a professional digital planimeter.

RESULTS

The glucose profiles showed a high frequency of prolonged hyperglycemic periods (80% of subjects) and a low frequency of postmeal glycemic peaks (29% of subjects). Postlunch values were significantly correlated with HbA(1c) levels, but the correlation disappeared when controlling for glucose area values. Glucose area values significantly correlated with HbA(1c) levels both when considered as a whole (40-400 mg/dl; r = 0.53, P = 0.002) and when considered fractioned (40-150, 40-200, 40-250, 40-300 mg/dl), apart from the 40-90 mg/dl partial area. HbA(1c) levels were significantly decreased 3 and 6 months after use of CGMS (P = 0.05 and 0.03, respectively, paired Student's t test).

CONCLUSIONS

HbA(1c) levels may be decreased by using the information obtained with the CGMS. Three-day glucose profiles are representative of the overall glucose control, because glucose area values correlate with HbA(1c) levels. The only glucose threshold below which there seems to be no correlation with HbA(1c) is 90 mg/dl. Only glucose area, and not postprandial glucose values, are directly and independently correlated with HbA(1c). Therefore, to improve metabolic control, it is necessary to lower the whole mean 24-h glycemia and not just the postprandial glucose values.

Immediate and delayed two-stage post-mastectomy breast reconstruction with implants. Our experience of general surgeons

BACKGROUND

Breast reconstruction after a mastectomy, today is considered the best choice to improve the quality of life for the patient. The aim of the procedure is to consider the aesthetic results obtained and the various involvements, comparing them with those already reported in literature. METHODS. There is no certain data of the number of breast reconstructions performed in Italy in the few years. In 1999, in Veneto, reconstruction surgery after total breast removal, represented only 16% of the operations. In our surgery Division, from 1996 to 2000, there were breast reconstructions performed, either immediately or delayed on 87 patients out of 118 after mastectomy. 73.7% none over the age of 60 (range 27-60). The breast removal technique used is the Madden, while, for the reconstruction we have put into effect the submuscle prosthetic implant; 63 patients were subject to follow-up treatment during the period of 10 to 36 months.

RESULTS

Seventy-eight percent of the women have judged the final aesthetic results the same or better than expected. Based on reconstruction with prosthesis, is the preferred procedure, even with serious complications which do not always influence the final results. This preference is because of the reduced operation time and the psychological and physical benefits due to immediate restoral of the mammary volume and shape.

CONCLUSIONS

Some problems (Garavaglia Law) have slowed down the diffusion in Italy of this type of treatment which is now receiving more and more request and approval by the women affected with breast cancer.

Enhanced activity of the plasma membrane oxidoreductase in circulating lymphocytes from insulin-dependent diabetes mellitus patients

Circulating human lymphocytes contain a transmembrane oxidoreductase (PMOR) capable of reducing dichlorophenol indophenol (DCIP) by endogenous reductants, presumably NADH. Membranes from lymphocytes obtained from buffy coats contain a NADH DCIP reductase having a K(m) of about 1 microM and almost insensible to dicoumarol. The PMOR of lymphocytes from insulin-dependent diabetic patients is higher than that from age-matched controls and, in addition, has a dicoumarol-sensitive component, lacking in most controls, presumably due to membrane association of DT-diaphorase. The increase of PMOR in diabetes is likely due to overexpression of the enzyme, in view of the very low K(m) for NADH indicating that, in intact cells, the enzyme is practically saturated with the reductant substrate.

Lymphocyte dysmetabolism: an immunocytochemical comparative approach in IDDM and control subjects

We have investigated by immuno-electron microscopy the presence of phosphotyrosine in cells as a whole and in different cell districts (nucleus, cytoplasm, plasma membrane, and mitochondria) in peripheral blood lymphocytes of IDDM (insulin-dependent diabetes mellitus) patients and age-matched controls. Immuno-gold particle density was highest in mitochondria and decreased in cytoplasm, nucleus and plasma membrane. The time dependence of phosphotyrosine labelling after cell isolation was very strong in all subcellular populations, with a fall in immunogold staining after 30 min. Staining levels at zero time were similar in controls and IDDM patients; the loss of phosphotyrosine labelling was much stronger in controls, except in the plasma membrane. Plasma membrane NADH oxidoreductase activity, studied using cytosolic NADH as substrate and assayed with DCIP as acceptor, was significantly increased in IDDM patients, suggesting a response to a deficient mitochondrial energetic activity. The fact that NADH oxidoreductase is a growth factor related to tyrosine phosphorylation pathways raises intriguing questions on the cellular derangement occurring in peripheral lymphocytes in IDDM, although the relationships among the immunocytochemical and biochemical changes is still obscure.

Diabetic retinopathy in childhood: long-term follow-up by fluorescein angiography beginning in the first months of disease

BACKGROUND

Little is known about minimal retinal lesions occurring in the first months of disease in children with type 1 diabetes mellitus (DM).

OBJECTIVE

To detect any early retinal change and to evaluate its progression in children diagnosed with type 1 DM.

PATIENTS

From 1979 to 1997 we examined by fluorescein angiography at diagnosis or within 15 months from the onset of DM 130 young patients with type 1 DM (mean age at diagnosis 10.08 +/- 2.62 yr). In 112 patients follow-up by fluorescein angiography was performed every 1.26 years with a mean of 5.41 fluorescein angiographies/patient.

METHODS

The stage of retinopathy was graded to detect minimal lesions. We also considered sex, pubertal stage, HLA, family history of DM, disease duration and HbA1c levels.

RESULTS

At first examination, 14 out of 127 (11%) readable angiographies showed minimal retinal changes. There was no statistically significant difference between the patients with or without lesions for all parameters considered. The 112 patients examined during follow-up were divided as follows: Group A: no retinopathy at first examination; Group A1: no retinopathy during follow-up; Group A2: retinal changes during follow-up; Group B: retinal changes at the first examination. Mean HbA1c value evaluated during the whole follow-up was lower in group A1 than in group A2. HbA1c levels at onset of the disease were significantly different in the three groups: in group A1 it was lower than in group A2 and in group B.

CONCLUSIONS

The presence of early lesions in the first year of disease in 11% of patients is probably due to the method of examination, which may detect even minimal retinal changes. This may be correlated to the acute metabolic failure present at the onset of disease. The prolonged follow-up seems to demonstrate that the early changes are not necessarily a negative prognostic factor in the evolution of diabetic retinopathy. We confirm that duration of DM and metabolic control are the main factors influencing the course of retinopathy in these young patients. Early fluorescein angiography is not particularly useful in the management of children with DM.