Trust Your Gut: Strategies and Tactics for Intestinally Restricted Drugs

Non-absorbable small-molecule drugs targeted to the gut represent an alternative approach to safe, non-systemic therapeutics. Such drugs remain confined to the gastrointestinal tract upon oral dosing by virtue of their limited passive permeability, increasing the local concentration at the site of action while minimizing exposure elsewhere in the body. Herein we review the latest advances in the field of gut-restricted therapeutics, highlighting the different strategies and tactics that medicinal chemists have employed in pursuit of drugs with minimal intestinal absorption.

A convergent fragment coupling strategy to access quaternary stereogenic centers

The formation of quaternary stereogenic centers via convergent fragment coupling is a longstanding challenge in organic synthesis. Here, we report a strategy for the formation of quaternary stereogenic centers in...

Left aorto-ventricular tunnel: A differential diagnosis to aortic regurgitation

Left aorto-ventricular tunnel is a rare congenital heart disorder. A then 19-year-old young lady was referred to our clinic for chronic rheumatic heart disease with aortic regurgitation. However, because of an almost continuous murmur, and an unusual transthoracic echo, she underwent various investigations, finally revealing a rare type 2 left aorto-ventricular tunnel. She had been variously diagnosed as chronic rheumatic heart disease with aortic regurgitation, bicuspid aortic valve with aortic regurgitation, and then possibly coronary arterial (cameral) fistula (based on 2D transthoracic echo) and finally left aorto-ventricular tunnel. This is the first case described in South East Asia who is asymptomatic, apart from a murmur, and her long journey to this final diagnosis illustrates the need to "chase shadows" on echoes, to come to a proper conclusion for the patient.

Clinical and genetic analysis of long QT syndrome in two Malay children

Long QT syndrome (LQTS) is predominantly a genetic cardiac arrhythmia disorder. We report here our study on long QT syndrome from two children from Kelantan, Malaysia. Clinical and genetic findings of these two unrelated Malay children with LQTS is discussed. We found a Long QT, type 1 causal mutation, p.Ile567Thr in the KCNQ1 gene in the first child. A pathogenic mutation could not be detected in the second child, explaining the heterogeneity of this disease.

Arterial stiffness during acute and recovery phases of children with rheumatic fever

Acute rheumatic fever (ARF) is associated with systemic inflammation and arterial stiffness during the acute stage. It has not been reported if arterial stiffness remains after recovery. The aim of this study was to determine the arterial stiffness during acute stage and 6 months after recovery from ARF. Arterial stiffness was assessed by carotid femoral pulse wave velocity (PWV) in 23 ARF patients during the acute stage of ARF and 6 months later. Simultaneously, erythrocyte sedimentation rate (ESR) and other anthropometric measurements were taken during both stages. There was a significant reduction in PWV; 6.5 (6.0, 7.45) m/s to 5.9 (5.38, 6.48) m/s, p=0.003 6 months after the acute stage of ARF. Similarly, ESR was also significantly reduced from 92.0 (37.5, 110.50) mm/hr to 7.0 (5.0, 16.0) mm/hr, p=0.001. In conclusion, arterial stiffness improved 6 months after the acute stage with routine aspirin treatment; this correlates well with the reduction in systemic inflammation.

Older Age Group in Pregnancy is Associated with Increased Arterial Stiffness

Arterial stiffness is an index of vascular health; normal pregnancy is associated with reduced arterial stiffness. This cross sectional study compared arterial stiffness in older (≥35 years) and the younger (≤34 years) age groups of pregnant women. Arterial stiffness was assessed noninvasively in 66 pregnant women between 23 - 32 weeks gestation (41 women ≤ 34 years, 25 women ≥ 35 years) using the parameters pulse wave analysis and pulse wave velocity. Blood pressure (BP), body mass index (BMI), serum total cholesterol (TC) and fasting blood glucose (FBS) were also recorded. Mean ages of the younger and older age groups were 27.6±0.62 and 39.3±0.58 years; no significant difference was seen between the groups in their BMI, TC, FBS, SBP, DBP and gestational age. The older age group of women have increased arterial stiffness (augmentation index 19.4±1.9% vs 13.2±1.6%, p=0.015) and aortic stiffness (pulse wave velocity 8.7±0.3 vs 7.7±0.2 m/s, p=0.004) compared to the younger women. Linear regression analysis showed a positive significant correlation between age and augmentation index (R=0.278, p=0.026), and pulse wave velocity (R=0.350, p=0.004). We conclude that older pregnant women has increased arterial stiffness compared to a younger age group of pregnant women suggesting that vascular changes due to ageing occurs in pregnancy despite cardiovascular adaptations occurring in pregnancy.

"Fishing for lines": removal of endovascular catheters from the cardiovascular system

We present two infants whose endovascular lines were accidentally cut or fractured, and had to be retrieved via transcatheter means in the cardiac catheterisation laboratory. The first case was a two-month-old infant with transposition of the great arteries, requiring an emergency balloon atrial septostomy. An indwelling vascular catheter that was placed in the right femoral vein was accidentally cut and had migrated into the inferior vena cava, before being retrieved. The second case was a one-week-old neonate who presented with pneumonia at birth, and had a long intravenous catheter placed in the left saphenous vein, which became fractured, and subsequently migrated into the heart. This case presented as a pulmonary embolus with haemodynamic instability, as the catheter had partially obstructed the right ventricular outflow tract. This was later retrieved via transcatheter means.

Pulmonary haemosiderosis with juvenile idiopathic arthritis in a Malaysian child

A rare case of childhood pulmonary haemosiderosis with juvenile idiopathic arthritis is discussed, with particular reference to treatment with hydroxychloroquine and sildenafil for pulmonary hypertension which occurs secondary to this disease.

Method optimisation to assess endothelial function in females - Duration of GTN effect

Pulse-wave analysis (PWA) combined with pharmacological challenges has recently been used as a method to measure endothelial function. This involved administration of glyceryl trinitrate (GTN), followed by salbutamol as endothelium-independent and -dependent vasodilators, respectively. The duration of GTN effect needs to be established before the administration of salbutamol. Baseline augmentation index (AIx) and pulse-wave velocity (PWV) measurements were taken in 11 healthy female subjects (mean age 23.27 +/- 3.66 years). Sublingual GTN 0.5 mg was administered for 3 min, followed by AIx and PWV measurements every 5 min till 20 min and then every 10 min until 40 min post-GTN. Maximum change in AIx post-GTN was at 3 min with a mean change from the baseline of -17.86% +/- 4.40% (p < 0.001). There were no significant changes noted after 30 and 40 min with mean change being -0.82% +/- 2.61% and 0.14% +/- 3.20%, respectively (p > 0.05). Significant changes in PWV were noted at 5 and 10 min with the mean change of -0.33 +/- 0.36 m/s and -0.33 +/- 0.35 m/s, respectively (p = 0.01). There were no further changes noted at 15 min and thereafter (p > 0.05). A duration of at least 30 min after GTN is required for AIx and PWV values to reach their baseline. Thus, the administration of salbutamol should be given only after 30 min of sublingual GTN for the assessment of endothelial function.

Anomalous right pulmonary artery from the aorta

Anomalous origin of the right pulmonary artery is a rare form of congenital heart disease. It usually presents in early infancy with heart failure and rapid development of pulmonary hypertension. There are about 131 cases reported in the literature and we report one such case.

Percutaneous closure of atrial septal defect type ostium secundum using the new Intrasept occluder: Initial experience

We report the first experience obtained with the new Intrasept device. We attempted to treat 35 patients with a mean age of 43 +/- 21 years. The mean size of the defect was 17/15 mm. It was successfully closed in 31 patients. In the remaining four the device could not be stabilized because of excessive defect size. A small residual shunt was present immediately following implantation in three patients. No complications occurred during the procedure and at 6 months, 31 patients had an uneventful outcome. Only one patient had a small residual shunt. No thrombus, embolization, or device fracture was documented during a mean follow-up of 17 +/- 11 months. Percutaneous closure of ASD ostium secundum is feasible with the Intrasept device with a high success rate and very good medium-term outcome. Our initial experience and results were excellent with small to medium size defects, however, large defects (>20 mm) remain challenging.

Hydroxyzine-induced supraventricular tachycardia in a nine-year-old child

Hydroxyzine is a first generation antihistamine widely used in the paediatric population for a variety of conditions. A nine-year-old girl presented with supraventricular tachycardia while on clinical doses of hydroxyzine for pruritus. On arrival at the hospital, she was diaphoretic, with cool peripheries, poor peripheral pulses and a heart rate of 250/minute. There was a history of three palpitation episodes with chest tightness during the five months she was taking hydroxyzine. The supraventricular tachycardia eventually reverted to sinus rhythm with intravenous verapamil. Relevant cardiac examination and investigations had not shown any cardiac abnormalities. After discontinuing hydroxyzine, she had no further episodes of supraventricular tachycardia. To our knowledge, this is the first report of hydroxyzine induced-supraventricular tachycardia in the medical literature.

Hansenula anomala infection in a neonate

We present an unusual neonatal fungal infection, Hansenula anomala in a very low birthweight infant who underwent abdominal surgery for an omphalocele. Despite treatment with adequate doses of amphotericin B, the yeast continued to grow from the blood culture, and was only eradicated with the use of oral ketoconazole.