Overview of Human Cytomegalovirus Pathogenesis

Human cytomegalovirus (HCMV) is a betaherpesvirus with a global seroprevalence of 60-90%. HCMV is the leading cause of congenital infections and poses a great health risk to immunocompromised individuals. Although HCMV infection is typically asymptomatic in the immunocompetent population, infection can result in mononucleosis and has also been associated with the development of certain cancers, as well as chronic inflammatory diseases such as various cardiovascular diseases. In immunocompromised patients, including AIDS patients, transplant recipients, and developing fetuses, HCMV infection is associated with increased rates of morbidity and mortality. Currently there is no vaccine for HCMV and there is a need for new pharmacological treatments. Ongoing research seeks to further define the complex aspects of HCMV pathogenesis, which could potentially lead to the generation of new therapeutics to mitigate the disease states associated with HCMV infection. The following chapter reviews the advancements in our understanding of HCMV pathogenesis in the immunocompetent and immunocompromised hosts.

Under-dilated TIPS Associate With Efficacy and Reduced Encephalopathy in a Prospective, Non-randomized Study of Patients With Cirrhosis

BACKGROUND & AIMS

Portosystemic encephalopathy (PSE) is a major complication of trans-jugular intrahepatic porto-systemic shunt (TIPS) placement. Most devices are self-expandable polytetrafluoroethylene-covered stent grafts (PTFE-SGs) that are dilated to their nominal diameter (8 or 10 mm). We investigated whether PTFE-SGs dilated to a smaller caliber (under-dilated TIPS) reduce PSE yet maintain clinical and hemodynamic efficacy. We also studied whether under-dilated TIPS self-expand to nominal diameter over time.

METHODS

We performed a prospective, non-randomized study of 42 unselected patients with cirrhosis who received under-dilated TIPS (7 and 6 mm) and 53 patients who received PTFE-SGs of 8 mm or more (controls) at referral centers in Italy. After completion of this study, dilation to 6 mm became the standard and 47 patients were included in a validation study. All patients were followed for 6 months; Doppler ultrasonography was performed 2 weeks and 3 months after TIPS placement and every 6 months thereafter. Stability of PTFE-SG diameter was evaluated by computed tomography analysis of 226 patients with cirrhosis whose stent grafts increased to 6, 7, 8, 9, or 10 mm. The primary outcomes were incidence of at least 1 episode of PSE grade 2 or higher during follow up, incidence of recurrent variceal hemorrhage or ascites, incidence of shunt dysfunction requiring TIPS recanalization, and reduction in porto-caval pressure gradient.

RESULTS

PSE developed in a significantly lower proportion of patients with under-dilated TIPS (27%) than controls (54%) during the first year after the procedure (P = .015), but the proportions of patients with recurrent variceal hemorrhage or ascites did not differ significantly between groups. No TIPS occlusions were observed. These results were confirmed in the validation cohort. In an analysis of self-expansion of stent grafts, during a mean follow-up period of 252 days after placement, none of the PTFE-SGs self-expanded to the nominal diameter in hemodynamically relevant sites (such as portal and hepatic vein vascular walls).

CONCLUSIONS

In prospective, non-randomized study of patients with cirrhosis, we found under-dilation of PTFE-SGs during TIPS placement to be feasible, associated with lower rates of PSE, and effective.

What's new in paediatric hypertension?

Paediatric hypertension predisposes to hypertension and cardiovascular disease in adult life. Despite clear guidelines, there remains a lack of screening. Diagnosis remains challenging given the high rate of false-positive high blood pressure (BP) readings at a single visit; thus, multiple visits are required to confirm the diagnosis. Depending on the normative data sets used, hypertension in overweight and obese children can be underestimated by up to 20%. Specific BP targets are required for subgroups such as adolescents, children with chronic kidney disease (CKD) and type 1 diabetes. High dietary salt intake is a risk factor for cardiovascular disease. Given the rise in processed food consumption, children in developed nations are likely to benefit from salt restriction at a population-based level.

Cardiovascular health, growth and gonadal function in children and adolescents with congenital adrenal hyperplasia

After the introduction of replacement therapy with glucocorticoids and mineralocorticoids in the 1950s, congenital adrenal hyperplasia (CAH) is no longer a life-limiting condition. However, due to the successful introduction of medical steroid hormone replacement, CAH has become a chronic condition, with associated comorbidities and long-term health implications. The aim of treatment is the replacement of mineralocorticoids and glucocorticoids and the normalisation of elevated androgen concentrations. Long-term consequences of the condition and current treatment regimens include unfavourable changes in the cardiovascular risk profile, impaired growth, testicular adrenal rest tumours (TART) in male and subfertility in both male and female patients with CAH. Optimising replacement therapy in patients with CAH remains challenging. On one hand, treatment with supraphysiological doses of glucocorticoids might be required to normalise androgen concentrations and decrease size or presence of TARTs. On the other hand, treatment with supraphysiological doses of glucocorticoids is associated with an increased prevalence of unfavourable cardiovascular and metabolic risk profiles as well as impaired longitudinal growth and gonadal function. Therefore, treatment of children and adults with CAH requires an individualised approach. Careful monitoring for early signs of complications is already warranted during paediatric healthcare provision to prevent and reduce the impact of comorbidities in later life.

Beneficial effect of troxerutin on diabetes-induced vascular damages in rat aorta: histopathological alterations and antioxidation mechanism

BACKGROUND

Diabetes is associated with micro- and macro-vascular complications affecting several organs. Oxidative stress plays a crucial role in the etiology of vascular disease in diabetes.

OBJECTIVES

The present study aimed to investigate the beneficial effect of troxerutin on diabetes-induced histopathological damages in rat aorta with focusing on its antioxidative actions.

MATERIALS AND METHODS

Male Wistar rats were randomly divided into four groups (n = 8/each): control, control plus troxerutin, diabetic and diabetic plus troxerutin. Diabetes was induced in rats by a single intraperitoneal injection of streptozotocin (50 mg/kg) and lasted for 10 weeks. Troxerutin was administered orally in concentration of 150 mg/kg/daily for one month before killing rats. At the end of treatment period, thoracic aorta was isolated and divided into two parts; one part was immersed in 10% formalin for histopathological evaluations and the other was frozen by liquid nitrogen for assessment of malondialdehyde (MDA, the main product of lipid peroxidation), activity of antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPX).

RESULTS

Lipid deposition in tunica intimae and media, thickening and structural deformity of vascular tissues as well as the level of plasma glucose and aortic tissue levels of lipid peroxidation were significantly increased in diabetic rats compared to control ones (P < 0.05). Troxerutin significantly reduced the severity of all vascular histopathological damages in treated versus untreated diabetic rats. In addition, treatment of diabetic rats with troxerutin significantly decreased the levels of MDA (5.1 ± 0.3 vs. 9.3 ± 1.2 nmol/mL) (P < 0.01) and increased the activity of antioxidant enzyme GPX compared to untreated-diabetic groups.

CONCLUSIONS

Troxerutin may reduce the vascular complications and tissue injuries induced by chronic diabetes in rat aorta through increasing the activity of tissue antioxidant system and reducing the level of lipid peroxidation.

Paediatric cerebral sinovenous thrombosis: findings of the International Paediatric Stroke Study

OBJECTIVES

We evaluated clinical features, treatment practices and early outcome in a multicentre cohort of children with cerebral sinovenous thrombosis (CSVT).

METHODS

Children with CSVT from 10 countries were enrolled from January 2003 to July 2007 in the International Paediatric Stroke Study. We analysed clinical symptoms, underlying conditions, antithrombotic treatment and neurological outcome at hospital discharge in 170 children.

RESULTS

Of 170 children enrolled, 60% were male; median age 7.2 years (IQR 2.9-12.4). Headache, altered consciousness, focal deficits and seizures were common presenting clinical features. Infarction affected 37% and intracranial haemorrhage 31%. Risk factors included chronic disease in 50%; acute systemic illness or head/neck disorders 41%; prothrombotic state 20% and other haematological abnormality 19%. Discharge neurological status was normal in 48%, abnormal in 43% and unknown in 5%. Antithrombotic therapy was common, most often low molecular weight heparin was common, with significant regional variation in treatment practices. Mortality was low (4%) and was associated with no anticoagulation but not underlying chronic disease, anatomic extent of thrombosis or intracranial haemorrhage. Abnormal neurological status at discharge or death was associated with decreased level of consciousness at presentation and the presence of an identified prothrombotic state.

CONCLUSIONS

Our study extends the observations of previously published smaller studies in children with CSVT that this is a morbid disease with diverse underlying causes and risk factors. Divergent treatment practices among highly specialised centres as well as limited data on treatment efficacy and safety suggest that further study of this condition is warranted.

Prematurity and programming of cardiovascular disease risk: a future challenge for public health?

There is substantial epidemiological evidence linking low birth weight with adult cardiometabolic disease risk factors. This has led to the concept of 'early life programming' or the 'developmental origins of disease' which proposes that exposure to adverse conditions during critical stages of early development results in compensatory mechanisms predicted to aid survival. There is growing evidence that preterm infants, many of whom are of low birth weight, are also at increased risk of adult cardiometabolic disease. In this article, we provide a broad overview of the evidence linking preterm birth and cardiovascular disease risk and discuss potential consequences for public health.

In adolescence, extreme prematurity is associated with significant changes in the microvasculature, elevated blood pressure and increased carotid intima-media thickness

OBJECTIVES

Increased carotid intima-media thickness (cIMT) and loss of capillary density are antecedents of cardiovascular disease in adults. Former preterm infants are at risk for metabolic precursors of vascular disease, but vascular changes have not yet been studied in this population.

PATIENTS AND METHODS

In 54 former preterm (birth weigh (BW) 753±152 g) and 12 term children (BW 3395±558 g), functional vessel density (FVD) on the forearm and cIMT were obtained at a mean (±SD) age of 11.8±1.5 years. FVD was measured using sidestream dark field imaging before, during and after arterial occlusion, and cIMT using high resolution B-mode ultrasonography. Statistical comparisons were made using the t test, Mann-Whitney U test and the sign test for symmetry, with a two-sided p value as appropriate.

RESULTS

The systolic blood pressure of the former preterm children was significantly increased compared to reference values (females 119±8, z score 1.23; males 118±11, z score 1.14 mm Hg), as were the cIMT values (0.45±0.03 mm vs 0.38±0.04 mm; p<0.001). FVD was significantly higher in former preterm children compared to controls at baseline (mean±SD 33.6±14.5 cm/cm(2) vs 23.0±7.1 cm/cm(2); p=0.002) with decreased reactivity during arterial occlusion (χ(2) 7.14, p=0.008).

CONCLUSIONS

Preterm birth is associated with significant permanent alteration in the microcirculation and increased cIMT and systolic blood pressure. It is unknown whether these changes are due to preterm birth and rapid maturation of the skin or to nutritional factors, as previously thought. This is an important area of future research.

Recent advances in paediatric dermatology

The past year has produced several new clinical guidelines germane to paediatric dermatology, as well as important work related to rheumatologic overlap disorders, psoriasis comorbidities, pigmented lesions and quality of life impact. This review highlights common diagnoses and treatments useful for the practicing paediatrician.

Serious adverse events and visual outcomes of rescue therapy using adjunct bevacizumab to laser and surgery for retinopathy of prematurity. The Indian Twin Cities Retinopathy of Prematurity Screening database Report number 5

AIM

To report serious adverse events and long-term outcomes of initial experience with intraocular bevacizumab in retinopathy of prematurity (ROP).

METHODS

Consecutive vascularly active ROP cases treated with bevacizumab, in addition to laser and surgery, were analysed retrospectively from a prospective computerised ROP database. Primary efficacy outcome was regression of new vessels. Secondary outcomes included the anatomic and visual status. Serious systemic and ocular adverse events were documented.

RESULTS

24 ROP eyes in 13 babies, received single intraocular bevacizumab for severe stage 3 plus after failed laser (seven eyes), stage 4A plus (eight eyes), and stage 4B/5 plus (nine eyes). Drug was injected intravitreally in 23 eyes and intracamerally in one eye. New vessels regressed in all eyes. Vision salvage in 14 of 24 eyes and no serious neurodevelopmental abnormalities were noted up to 60 months (mean 30.7 months) follow-up. Complications included macular hole and retinal breaks causing rhegmatogenous retinal detachment (one eye); bilateral, progressive vascular attenuation, perivascular exudation and optic atrophy in one baby, and progression of detachment bilaterally to stage 5 in one baby with missed follow-up. One baby who received intracameral injection developed hepatic dysfunction. One eye of this baby also showed a large choroidal rupture.

CONCLUSIONS

Though intraocular bevacizumab, along with laser and surgery salvaged vision in many otherwise progressive cases of ROP, vigilance and reporting of serious adverse events is essential for future rationalised use of the drug. We report one systemic and four ocular adverse events that require consideration in future use of the drug.

Studies on homocysteine demonstrating its significance as a possible tool for differential diagnosis in occlusive vascular disease

Homocysteine (Hcy) is a non-protein forming amino-acid, whose metabolism is at the intersection of two metabolic pathways: remethylation and transsulfuration which are dependent on the vitamins folic acid, B(12) and B(6), and the enzymes methylenetetrahydrofolate reductase and cystathionine-β-synthetase. A deficiency of any of these vitamins or enzymes results in hyperhomocysteinemia. This causes oxidative and other damage to blood vessels, thus affecting various organ systems of the body. As part of our ongoing research on cardiovascular risk factors, we have studied the Hcy levels in the plasma of normal controls and those suffering from vascular diseases. It was observed that Hcy is significantly higher in patients of vascular diseases (21.59±1.28 μmol/L, mean±SEM), as compared to normal controls (11.33±0.18 μmol/L). This significance, was more pronounced in cases of venous thrombosis (26.77±2.43 μmol/L) as opposed to cases of arterial block (17.27±0.84 μmol/L). This signifies that Hcy estimation would be beneficial in obtaining a differential diagnosis in addition to being a modifiable vascular risk factor.