Nitric oxide activity in childhood hypertension

OBJECTIVES: To investigate nitric oxide (NO) activity in childhood hypertension using nitrite and nitrate (NOx) concentrations in plasma as an index of nitric oxide generation. DESIGN: Cross sectional study. SETTING: Tertiary care paediatric centre and district general hospitals in the UK. PATIENTS: Children attending the above centre for treatment of hypertension. The control subjects were normotensive healthy children attending district general hospitals for minor medical and surgical disorders. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Plasma (P) and urinary (U) NOx concentrations, blood pressure, and glomerular filtration rate. RESULTS: Sixteen normal children (mean age 6.9 years), 13 children with renovascular hypertension (mean age 7.8 years), and 25 children with hypertension associated with renal parenchymal disease (mean age 10.7 years) were studied. Mean (SD) PNOx values of children with hypertension with renovascular disease (15.3 (11.4) mumol/l) and renal parenchymal disease (18.3 (11.4) mumol/l) were significantly above that of normal children (11.9 (5.9) mumol/l) after accounting for age and glomerular filtration rate influences. Higher concentrations of PNOx in normal children were associated with younger age, but not in the children with hypertension. Higher PNOx concentrations were also associated with a lower glomerular filtration rate in normal children and children with hypertension with renal parenchymal disease, but not in the children with hypertension with renovascular disease. UNOx excretion expressed as a ratio against urine creatinine (Ucreat) excretion was not statistically different among the study groups. CONCLUSIONS: PNOx is increased in children with hypertension even after statistical elimination of the glomerular filtration rate and age influences. This suggests a normal or increased NO synthase activity in childhood hypertension in contrast with adults with hypertension in whom it is described as reduced.     

Varicella and zoster in children after kidney transplantation: long-term results of vaccination

OBJECTIVE: To determine the long-term prevalence of varicella infection and herpes zoster after kidney transplantation and to assess the effectiveness of varicella immunization with the Oka attenuated strain. METHODS: This study involved 704 children and adolescents who received a kidney graft in our institution from 1973 to 1994 and had routinely been given varicella vaccine beginning in 1980 in preparation for transplantation. RESULTS: After vaccination 62% of these patients still had varicella/zoster (VZ) antibodies at 1 year and 42% after 10 years. After transplantation the incidence of varicella was significantly lower, 26/212 (12%), in patients who received immunization than in those who did not and had no history of varicella, 22/49 (45%). The disease was also significantly less severe in the vaccinated patients (three deaths among naive patients vs none among vacciness). In the vaccinees, varicella infection was observed only in those who did not develop or lost VZ antibodies; in addition, 21 patients of this subgroup had an asymptomatic seroconversion. Four of the 415 patients with a history of varicella had another episode of benign varicella after grafting. Herpes zoster was observed in 76 of the 704 patients included in the study. The prevalence differed according to VZ status at the time of grafting: 13% in patients with a history of varicella, 7% in the vacciness, and 38% in the naive patients at grafting who developed varicella. Three rejection episodes occurred in association with a varicella episode and four with a zoster episode, but graft function was only transiently impaired, and as a whole varicella or zoster did not significantly affect graft function or survival. CONCLUSION: Naive VZ patients with a kidney graft are at risk to develop severe varicella and this may be effectively prevented by available immunization.     

Altered gap junctional intercellular communication in neoplastic rat esophageal epithelial cells

Gap junctional intercellular communication (GJIC) is reduced in many neoplastic cells, but few data exist for esophageal neoplasms. GJIC was examined by fluorescent dye microinjection in two nontumorigenic and two highly tumorigenic rat esophageal epithelial cell lines. All lines expressed high levels of dye coupling in homologous cell culture. In cocultures of nontumorigenic and tumorigenic cells, however, only one of six cell combinations displayed significant heterologous GJIC. Northern, Western, and immunohistochemical analyses indicated that all four cell lines expressed comparable levels of connexin43 (Cx43), but not connexin32 or connexin26, and formed Cx43-containing gap junction plaques at cell-cell interfaces. Immunostaining of rat esophageal frozen sections demonstrated that esophageal epithelial cells expressed Cx43 in vivo. In normal epithelium, the highest expression was seen in the basal cells and little suprabasal staining was evident. In preneoplastic and neoplastic lesions of the esophageal epithelium which were induced by treating rats with N-nitrosomethylbenzylamine, Cx43 staining of the basal layer was also seen but appeared to be more diffuse compared to normal epithelium. In addition, suprabasal Cx43 staining was apparent in dysplastic and papillomatous lesions. These results indicate that Cx43 is expressed in normal and neoplastic rat esophageal cells and that the cells exhibit extensive homologous GJIC, but little heterologous GJIC. This lack of heterologous GJIC may be due to differences in cell adhesion proteins or other factors.      

Skin dose from radiotherapy X-ray beams: The influence of energy

Skin-sparing properties of megavoltage photon beams are compromised by electron contamination. Higher energy beams do not necessarily produce lower surface and basal cell layer doses due to this electron contamination. For a 5 ± 5cm field size the surface doses for 6 MVp and 18MVp X-ray beams are 10% and 7% of their respective maxima. However, at a field size of 40x40cm the percentage surface dose is 42% for both 6 MVp and 18 MVp beams. The introduction of beam modifying devices such as block trays can further reduce the skin-sparing advantages of high energy photon beams. Using a 10mm perspex block tray, the surface doses for 6MVp and 18MVp beams with a 5x5cm field size are 10% and 8%, respectively. At 40x40cm, surface doses are 61 % and 63% for 6MVp and 18MVp beams, respectively. This trend is followed at the basal cell layer depth. At a depth of 1 mm, 18 MVp beam doses are always at least 5% smaller than 6 MVp doses for the same depth at all field sizes when normalized to their respective Dmax values. Results have shown that higher energy photon beams produce a negligible reduction of the delivered dose to the basal cell layer (0.1 mm). Only a small increase in skin sparing is seen at the dermal layer (1 mm), which can be negated by the increased exit dose from an opposing field.     

Child health statistical review, 1996

There is much evidence that the children born in the last decade of the 20th century are healthier and living longer than children born earlier this century, and that children born too small or too soon are now more likely to reach adulthood than similar children born 10 or 20 years ago. Yet measures of social disadvantage (poverty, underachievement in education, lone parenthood) are increasing, putting this generation of children at higher risk of morbidity later in life.     

Occurrence of Duchenne dystrophy in Klinefelter's syndrome

A boy with Duchenne muscular dystrophy and facial dysmorphism in conjunction with Klinefelter's genotype 47XXY is presented; this is an unusual situation with two genetic errors evolving over two generations. Karyotyping should be considered in boys with Duchenne muscular dystrophy who have unusual features.     

Serum interleukin-1 alpha and soluble interleukin-2 receptor concentrations in cystic fibrosis

Interleukin (IL)-1 and IL-2 may participate in the systemic inflammatory response and hypergammaglobulinaemia observed in patients with cystic fibrosis. Thirty seven patients with cystic fibrosis were compared with 25 normal controls. High IgG and IgM concentrations were associated with more severe pulmonary disease. IL-1 alpha and soluble IL-2 receptor concentrations were higher in the cystic fibrosis group than in the controls and also correlated with concentrations of IgG and IgM. These results suggest that these cytokines may contribute to enhanced immunoglobulin synthesis and silent inflammatory activity in clinically stable patients with cystic fibrosis.