Outbreak of measles in primary school students with high first dose MMR vaccination coverage

INTRODUCTION

Indigenous cases of measles continue to occur in Singapore despite the implementation of a two-dose mumps, measles and rubella (MMR) vaccination policy in 1998. We investigated a measles outbreak that took place in a primary school from April 17 to May 6, 2004 to identify all cases, evaluate vaccine efficacy (VE) and implement outbreak control measures.

METHODS

A case of measles was defined as anyone having generalised rash and fever with or without cough, coryza or conjunctivitis during the outbreak period, and who had either laboratory-confirmed acute measles infection or was epidemiologically linked to a patient with laboratory-confirmed measles infection. Vaccination status was obtained from the studentos health booklet and confirmed with the National Immunisation Registry. Attack rates in unvaccinated (ARU) and vaccinated (ARV) students were calculated and VE was evaluated using the formula: VE (percent) = [(ARU-ARV) / ARU] x 100 percent.

RESULTS

Nine students, aged between eight and 14 years, from five classes in primary three and primary six, were epidemiologically linked to have measles. None of them had received the second dose of the MMR vaccine. 93 percent of students in the affected classes (n = 184) had prior documented evidence of receiving at least one dose of MMR vaccination, as compared to 96.5 percent for the entire school enrolment (n = 1,309). The attack rate was 1.2 percent in the vaccinated group and 53.8 percent in the unvaccinated group. The VE for the primary dose of MMR in the affected classes was 97.8 percent.

CONCLUSION

It is important to achieve a high coverage for the primary dose of MMR vaccine in order to prevent any potential outbreaks prior to receiving the booster dose.

Modulation by simvastatin of iberiotoxin-sensitive, Ca2+-activated K+ channels of porcine coronary artery smooth muscle cells

BACKGROUND AND PURPOSE

Statins (3-hydroxy-3-methyl-glutaryl coenzyme A (HMG CoA) reductase inhibitors) have been demonstrated to reduce cardiovascular mortality. It is unclear how the expression level of HMG CoA reductase in cardiovascular tissues compares with that in cells derived from the liver. We hypothesized that this enzyme exists in different cardiovascular tissues, and simvastatin modulates the vascular iberiotoxin-sensitive Ca2+-activated K(+) (BK(Ca)) channels.

EXPERIMENTAL APPROACHES

Expression of HMG CoA reductase in different cardiovascular preparations was measured. Effects of simvastatin on BK(Ca) channel gatings of porcine coronary artery smooth muscle cells were evaluated.

KEY RESULTS

Western immunoblots revealed the biochemical existence of HMG CoA reductase in human cardiovascular tissues and porcine coronary artery. In porcine coronary artery smooth muscle cells, extracellular simvastatin (1, 3 and 10 microM) (hydrophobic), but not simvastatin Na+ (hydrophilic), inhibited the BK(Ca) channels with a minimal recovery upon washout. Isopimaric acid (10 microM)-mediated enhancement of the BK(Ca) amplitude was reversed by external simvastatin. Simvastatin Na+ (10 microM, applied internally), markedly attenuated isopimaric acid (10 microM)-induced enhancement of the BK(Ca) amplitude. Reduced glutathione (5 mM; in the pipette solution) abolished simvastatin -elicited inhibition. Mevalonolactone (500 microM) and geranylgeranyl pyrophosphate (20 microM) only prevented simvastatin (1 and 3 microM)-induced responses. simvastatin (10 microM ) caused a rottlerin (1 microM)-sensitive (cycloheximide (10 microM)-insensitive) increase of PKC-delta protein expression.

CONCLUSIONS AND IMPLICATIONS

Our results demonstrated the biochemical presence of HMG CoA reductase in different cardiovascular tissues, and that simvastatin inhibited the BK(Ca) channels of the arterial smooth muscle cells through multiple intracellular pathways.

Glucagon-like peptide-1 excites pancreas-projecting preganglionic vagal motoneurons

Glucagon-like peptide-1 (GLP-1) increases pancreatic insulin secretion via a direct action on pancreatic beta-cells. A high density of GLP-1-containing neurons and receptors is also present in brain stem vagal circuits; therefore, the aims of the present study were to investigate 1) whether identified pancreas-projecting neurons of the dorsal motor nucleus of the vagus (DMV) respond to exogenously applied GLP-1, 2) the mechanism(s) of action of GLP-1, and 3) whether the GLP-1-responsive neurons (putative modulators of endocrine secretion) could be distinguished from DMV neurons responsive to peptides that modulate pancreatic exocrine secretion, specifically pancreatic polypeptide (PP). Whole cell recordings were made from identified pancreas-projecting DMV neurons. Perfusion with GLP-1 induced a concentration-dependent depolarization in approximately 50% of pancreas-projecting DMV neurons. The GLP-1 effects were mimicked by exendin-4 and antagonized by exendin-(9-39). In approximately 60% of the responsive neurons, the GLP-1-induced depolarization was reduced by tetrodotoxin (1 microM), suggesting both pre- and postsynaptic sites of action. Indeed, the GLP-1 effects were mediated by actions on potassium currents, GABA-induced currents, or both. Importantly, neurons excited by GLP-1 were unresponsive to PP and vice versa. These data indicate that 1) GLP-1 may act on DMV neurons to control pancreatic endocrine secretion, 2) the effects of GLP-1 on pancreas-projecting DMV neurons are mediated both via a direct excitation of their membrane as well as via an effect on local circuits, and 3) the GLP-1-responsive neurons (i.e., putative endocrine secretion-controlling neurons) could be distinguished from neurons responsive to PP (i.e., putative exocrine secretion-controlling neurons).

Genetic regulation of patterned tubular branching in Drosophila

A common theme in organogenesis is the branching of epithelial tubes, for example in the lung, liver, or kidney. The later morphogenesis of these branched epithelia dictates the final form and function of the mature tissue. Epithelial branching requires the specification of branch cells, the eversion process itself, and, frequently, patterned morphogenesis to produce branches of specific shape and orientation. Using the branching of renal tubule primordia from the hindgut in Drosophila, we show that these aspects are coordinately regulated. Cell specification depends on Wnt signaling along the tubular gut and results in the spatially restricted coexpression of two transcription factors, Krüppel and Cut, in the hindgut, whose activity drives cells toward renal tubule fate. Significantly, these transcription factors also confer the competence to respond to a second signal; TGF-beta induces branching to form the four renal tubule buds. Differential activation of the TGF-beta pathway also patterns the tubules, resulting in the asymmetry in size and positioning that is characteristic of the two tubule pairs. High levels of TGF-beta promote the expression of Dorsocross1-3 and anterior tubule growth, whereas low levels allow the expression of the transcriptional repressor, Brinker, and thus promote posterior tubule identity. We show that patterning of the tubule primordium into two distinct pairs is critical for the eversion of tubule branches, as well as for their asymmetric morphogenesis.

Video assisted thoracic surgery in the management of spontaneous pneumothorax: the current status

Over the past decade, video assisted thoracic surgery (VATS) has changed the way spontaneous pneumothorax (SP) is managed. Benefits of VATS include less postoperative pain, shorter hospital stay, and attenuated postoperative inflammatory response are evident compared with open thoracic procedures. Furthermore, the increasing acceptance by patients and referring physicians is testament to its success. Recent studies and the authors decade of experience in management of SP by VATS show that it is quick, safe, and effective, with recurrence rates generally comparable to open procedures, with some exceptions. However, selecting the correct procedure and patient, as well as knowing the limitations of the surgeons and techniques are paramount for success. Even to this day, there are considerable variations in the treatment of SP and large scale controlled studies are needed to better define timing of surgery and the role of the different procedures in the treatment and prevention of SP.

Deferoxamine reduces CSF free iron levels following intracerebral hemorrhage

Iron overload occurs in brain after intracerebral hemorrhage (ICH). Deferoxamine, an iron chelator, attenuates perihematomal edema and oxidative stress in brain after ICH. We investigated the effects of deferoxamine on cerebrospinal fluid (CSF) free iron and brain total iron following ICH. Rats received an infusion of 100-microL autologous whole blood into the right basal ganglia, then were treated with either deferoxamine (100 mg/kg, i.p., administered 2 hours after ICH and then at 12-hour intervals for up to 7 days) or vehicle. The rats were killed at different time points from 1 to 28 days for measurement of free and total iron. Behavioral tests were also performed. Free iron levels in normal rat CSF were very low (1.1 +/- 0.4 micromol). After ICH, CSF free iron levels were increased at all time points. Levels of brain total iron were also increased after ICH (p < 0.05). Deferoxamine given 2 hours after ICH reduced free iron in CSF at all time points. Deferoxamine also reduced ICH-induced neurological deficits (p < 0.05), but did not reduce total brain iron. In conclusion, CSF free iron levels increase after ICH and do not clear for at least 28 days. Deferoxamine reduces free iron levels and improves functional outcome in the rat, indicating that it may be a potential therapeutic agent for ICH patients.

EXTRA Trial-Evaluation of capecitabine treatment with radiotherapy (RT) in anal cancer: Preliminary results on toxicity and outcome

14085

Background: Phase III trials have shown RT + 5-Fluorouracil (5-FU) + mitomycinC (MMC) as the standard treatment for patients with epidermoid anal carcinoma. The objective of this trial is to determine if capecitabine in combination with MMC has a similar outcome in terms of complete response (CR) rate and toxicity to a 5-day infusion of 5-FU. Capecitabine is a rational alternative to 5-FU as these cancers express high levels of thymidine phosphoralase. Methods: Main eligibility criteria are histologically proven anal carcinoma (epidermoid, squamous, basaloid), fit to receive capecitabine and MMC and ineligible for the ongoing phase III UK trial, ACT II. Exclusion criteria include complete local excision, prior chemoradiation, uncontrolled cardiovascular disease and known HIV+ve. All patients receive: 50.4Gy in 28F(RT) and capecitabine 1650mg/m2/day on each RT treatment day (M-F) over 6 weeks. In addition patients receive MMC 12mg/m2, day 1 only. Assessment of response is by CT scan at 4 wks post chemoradiation. Results: To date 18/30 patients have been registered. Pre-treatment characteristics are: median age 59 yrs (44–85); 7 male, 11 female; 13 Canal, 5 Margin; 5T1, 4T2, 6T3, 2T4, 1Tx; 4N+ve, 13N-ve, 1Nx. Data on 14 evaluable pts are presented here. RT compliance: 12 pts completed planned treatment, treatment was interrupted in 2 cases (chest pain 1; machine breakdown 1). Chemotherapy compliance: 10 pts completed protocol treatment, in 3 pts chemotherapy was affected due to toxicity (1 dose reduced, 2 stopped early 1 due to chest pain and 1 due to grade 3 skin and diarrhoea). One patient decided to stop treatment. Grade 3 toxicity was reported in 2 pts during treatment: dyspnoea 1, diarrhoea 1. Four weeks post chemoradition, 10 had CR, 3 had partial response and 1 pt was not assessable. Thirteen pts are alive and disease free at a median follow-up of 6 months (range 1 -13). One pt has relapsed in an inguinal node 9 months after the end of treatment following a previous CR. Conclusions: This early information suggests that this regimen can be given without interruption and with acceptable toxicity. The early response data is encouraging and the trial aims to reach target accrual by Summer 2006. Educational grant provided by Roche pharmaceuticals.

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Pulmonary ischaemia-reperfusion injury: role of apoptosis

The central role of lung ischaemia-reperfusion injury in pulmonary dysfunction after cardiac surgery, particularly thoracic organ transplantation, has been well recognised. Lung tissue necrosis after prolonged ischaemia is known to worsen lung function, which was believed to be due largely to adjacent tissue inflammation. Recent studies suggest that lung apoptosis following ischaemia-reperfusion could be equally important in the development of post-operative lung dysfunction. The current literature on the mechanism and pathways involved in pulmonary dysfunction and, in particular, its relationship with apoptosis after lung ischaemia-reperfusion is briefly reviewed here. A better understanding of lung apoptosis, as well as the upstream pathways, may help in the development of therapeutic strategies that could benefit patients undergoing cardiac and lung transplantation.

Optically controlled Sagnac loop comb filter

We propose a new type of dynamically tunable birefringence comb filter based on a semiconductor optical amplifier Sagnac loop interferometer. By optically modulating the birefringence of the amplifier, we demonstrate a tuning of the output wavelengths. The shift of wavelength increases monotonically with the power of the control light until saturation occurs. The tuning relation is independent of the comb spacing governed by the length and birefringence of the polarization maintaining fiber inside the loop. A tuning range up to 59% of the comb spacing has been achieved at 18.5 dBm input power.

Idiopathic localised bladder amyloidosis: rare cause of haematuria

Idiopathic Localised Bladder Amyloidosis is a rare cause of haematuria and urinary tract symptoms. A review of the literature highlights the varied presentations and the appropriate investigations for this condition, with emphasise on the exclusion of a secondary cause. In addition, the range of treatment options is fully discussed. Our report on a 65-year old gentleman illustrates that a high index of suspicion is required for its diagnosis. Furthermore, conservative management can be an effective strategy in selected patients.

An endothelin type A receptor antagonist inhibits neointimal hyperplasia and increases luminal area in porcine vein grafts

Background

Neointimal hyperplasia is responsible for the majority of cases of vein graft failure. To date, no pharmacological intervention has proved successful in preventing this process in humans. Endothelin (ET) 1 is a potent vasoconstrictor and promotes the proliferation of vascular smooth muscle cells in vitro. The authors have shown previously that porcine vein grafts contain high levels of ET-1 and ET type A (ETA) receptor subtypes. The aim was to investigate the effect of an ETA receptor antagonist, BSF 302146, on luminal area and graft wall dimensions in a porcine model of arteriovenous bypass grafting.

Methods

Bilateral saphenous vein–carotid artery interposition grafting was performed in two groups of Large White pigs (26–32 kg; n = 5 per group). BSF 302146 (10 mg kg−1 day−1) was administered orally to animals in group 1; group 2 animals acted as controls. After 4 weeks the grafts were explanted and pressure-fixed ex vivo. Histological sections were obtained and graft dimensions assessed by means of computer-aided planimetry.

Results

BSF 302146 significantly reduced both neointimal hyperplasia and medial thickening, and increased luminal area by 77 per cent.

Conclusion

The ETA receptor antagonist BSF 302146 inhibits neointimal hyperplasia and increases luminal area in a porcine model of saphenous vein bypass grafting.

Does external stenting reduce porcine vein-graft occlusion via an action on vascular nerves?

BACKGROUND

Neural reorganization occurs in porcine vein grafts and placement of an external stent reduces graft occlusion.

AIM OF THE STUDY

To determine the effect of external stenting on the innervation of porcine vein grafts.

METHODS

Saphenous vein into carotid artery grafting (with and without external stents) was performed in 16 pigs. After one and six months, grafts were removed, nerves were counted, and neointima was assessed.

RESULTS

In vein graft compared to ungrafted vein, there was a significant (p < 0.05) decrease in medial perivascular nerves, but a dramatic increase in paravascular nerves in the adventitia (p < 0.05). In stented vein grafts there was also a reduction of perivascular nerves and the paravascular nerve proliferation observed in vein grafts at one month was inhibited (p < 0.05). Neointima formation and the appearance of large paravascular nerve bundles in the adventitia of vein grafts were abolished by external stenting.

CONCLUSIONS

Neural reorganization plays a role in vein-graft failure, possibly through the local release of mitogens; the prevention of this reorganization contributes to the inhibitory effect of the external stent on neointima formation.

Video-assisted thoracic surgery for mediastinal extramedullary haematopoiesis

Extramedullary haematopoiesis is a rare cause of an intrathoracic mass. We report a case of posterior mediastinal extramedullary haematopoietic mass in a 50-year-old man who presented with non-specific symptoms and a paravertebral mass on chest X-ray. Diagnosis was achieved by using video-assisted thoracic surgery.

Acclimatization of soil respiration to warming in a tall grass prairie

The latest report by the Intergovernmental Panel on Climate Change (IPCC) predicts a 1.4-5.8 degrees C average increase in the global surface temperature over the period 1990 to 2100 (ref. 1). These estimates of future warming are greater than earlier projections, which is partly due to incorporation of a positive feedback. This feedback results from further release of greenhouse gases from terrestrial ecosystems in response to climatic warming. The feedback mechanism is usually based on the assumption that observed sensitivity of soil respiration to temperature under current climate conditions would hold in a warmer climate. However, this assumption has not been carefully examined. We have therefore conducted an experiment in a tall grass prairie ecosystem in the US Great Plains to study the response of soil respiration (the sum of root and heterotrophic respiration) to artificial warming of about 2 degrees C. Our observations indicate that the temperature sensitivity of soil respiration decreases--or acclimatizes--under warming and that the acclimatization is greater at high temperatures. This acclimatization of soil respiration to warming may therefore weaken the positive feedback between the terrestrial carbon cycle and climate.

Giant pulmonary bulla

The present report describes a case of a giant pulmonary bulla in a 32-year-old man that progressed to occupy almost the entire left hemithorax. This report is unique in documenting the natural history of progression of this condition. Bullectomy was performed using the video-assisted thoracoscopic surgery approach.

Rates of cesarean births in Hong Kong: 1987-1999

BACKGROUND

High cesarean birth rates are an issue of international public health concern. The purpose of this paper was to examine the annual incidence and secular trend of cesarean births in Hong Kong and to correlate these rates with socioeconomic, demographic, and health indicators for the population since 1987.

METHODS

This was a descriptive and ecologic study. Annual population rates of cesarean sections were estimated for 1987 from a population-based survey, and for 1993 through 1999 from government data sources. The number of excess cesarean sections was calculated for each year using the 15 percent upper limit as proposed by the World Health Organization.

RESULTS

From 1987 to 1999 the overall annual cesarean section rate rose steadily from 16.6 to 27.4 per 100 hospital deliveries, resulting in a 65 percent increase over 12 years. The mean difference in rates of surgical delivery between public (mean(public) = 16.0%) and private (mean(private) = 43.4%) institutions was 27.4 percent (95% confidence interval (CI) = 24.1, 30.7; p < 0.001).

CONCLUSIONS

This is the first systematic report of secular variations of cesarean delivery rates in Asia. The high rates and increasing trend represent an unnecessary excess risk for mothers and their infants. Various strategies combating high cesarean rates have been proposed and have succeeded elsewhere. Concerted action from health care professionals, public health authorities, the general population, and the media is urgently required to implement solutions to reduce the rate of cesarean delivery.

[Isozyme analysis of Gastrodia elata f. elata and G. elata f. glaucca and their hybrid]

Peroxidase(POX) isozyme analysis of Gastrodia elata f. glaucca, G. elata f. elata and its hybrid were carried out. The results indicated that shoot apex meristem was optimal material for POX analysis and the determination of the hybrid. The zymogram hands were stable and clear. POX isozyme zymogram of the hybrid F1(H x W) represented the visible supplement relation between Gastrodia elata f. elata and Gastrodia elata f. glaucca.

Intentional internal iliac artery occlusion to facilitate endovascular repair of aortoiliac aneurysms

PURPOSE

The safety of intentional occlusion of patent internal iliac arteries (IIAs) to facilitate the endovascular repair of aortoiliac artery aneurysms (abdominal aortic aneurysms [AAAs] and iliac aneurysms [IAs]) was evaluated.

METHODS

We analyzed the techniques and clinical sequelae of selective occlusion of one or both IIAs in 103 patients and correlated these findings with the results of preoperative angiograms to identify vascular anatomy that may predict postoperative pelvic ischemia. To quantify the clinical presentation of pelvic ischemia, we developed these criteria: class 0, no symptoms; class I, nonlimiting claudication with exercise; class II, new onset impotence, with or without moderate to severe buttock pain, leading to physical limitation with exercise; class III, buttock rest pain, colonic ischemia, or both. IIA occlusion was achieved in 100% of the patients by means of either catheter-directed embolization or orificial coverage with a stent-graft. No patient in this study had angiographic evidence of significant visceral occlusive disease before the procedure. Sixty-four patients had isolated AAAs, 23 patients had AAAs and IAs, and 16 patients had isolated IAs. Ninety-two patients had one IIA selectively occluded, and 11 patients had both IIAs selectively occluded.

RESULTS

After IIA occlusion, 12 patients were categorized in class I, 9 patients were categorized in class II, and 1 patient was categorized in class III, for a total of 22 patients (21%) with pelvic ischemia. Sixteen (17%) of 92 patients had unilateral IIA occlusions, and six (17%) of 11 patients had bilateral IIA occlusions. Five patients in class I improved and had no symptoms within 1 year, and one patient in class II was downgraded to class I because of improved symptoms. Two unique preoperative angiographic findings were identified in the remaining 16 patients (16%) with chronic pelvic claudication: (1) stenosis of the remaining IIA origin (> 70%) with nonopacification of more than three of the six IIA branches (63%); and (2) small caliber, diseased or absent medial and lateral femoral circumflex arteries ipsilateral to the side of the IIA occlusion (25%). One patient with class III ischemia died of cardiovascular collapse associated with colon infarction caused by either acute ischemia or particulate embolization.

CONCLUSION

The incidence of pelvic ischemia after IIA occlusion is 20% immediately after endovascular aortoiliac aneurysm repair. A total of 25% of patients had no symptoms within 1 year. Two preoperative radiologic findings may help identify patients who are at risk for pelvic ischemia: stenosis of the patent IIA and disease deep femoral ascending branches ipsilateral to the occluded IIA. The risk of colon ischemia appears to be small after selective IIA occlusion to facilitate endovascular AAA repair.