Endovascular management of a large hepatic artery aneurysm related to type B aortic dissection.

Management of visceral artery aneurysms can be challenging: there is limited evidence to determine size thresholds for intervention and it is often technically difficult to exclude the aneurysms while preserving visceral perfusion. We present the case of a 68-year-old male with a rapidly enlarging hepatic artery aneurysm related to type B aortic dissection extending into the coeliac axis, which presented unique difficulties due to its morphology and filling via the false lumen. Endovascular treatment involved stent-graft placement from the coeliac axis into the splenic artery with the intention of excluding the coeliac supply to the common hepatic artery. Despite early stent-graft occlusion, the aneurysm was successfully excluded and adequate hepatic and splenic perfusion was maintained. The patient made a good recovery.

Validation of a Decision Tree to Streamline Infrainguinal Vein Graft Surveillance.

BACKGROUND: Duplex ultrasound (DU)-based graft surveillance remains controversial. The aim of this study was to assess the ability of a recently proposed decision tree in identifying high-risk grafts which would benefit from DU-based surveillance. MATERIALS AND METHODS: Consecutive patients undergoing infrainguinal vein graft bypass from January 2008 to December 2015 were identified from the National Vascular registry and enrolled in a duplex surveillance program. An early postoperative DU was performed at a median of 6 weeks (range: 4-9 weeks). Grafts were classified into high risk or low risk based on the findings of the earliest postoperative scan and 4 established risk factors for graft failure (diabetes, smoking, infragenicular distal anastomosis, and revision bypass surgery) using a classification and regression tree (CRT). The accuracy of the CRT model was evaluated using area under receiver operator characteristic (AROC) curve. RESULTS: About 278 vein graft bypasses were performed; 29 grafts had occluded by the first surveillance visit; 249 vein grafts were entered into surveillance. Sixty-four (23%) developed critical stenosis. Overall 30-month primary patency, primary-assisted patency, and secondary patency rates were 71.2%, 77.2%, and 80.1%, respectively. AROC for prediction of graft stenosis or occlusion was 83% (95% confidence interval [CI]: 78-87%). The sensitivity and specificity of the CRT model for prediction of graft stenosis or occlusion were 95% (95% CI: 88-98%) and 52.2% (95% CI: 45-60%). CONCLUSIONS: A prediction model based on commonly recorded clinical variables and early postoperative DU scan is accurate at identifying grafts which are at high risk of failure. These high-risk grafts may benefit from DU-based surveillance.

Endovascular management of a penetrating abdominal aortic injury.

Penetrating aortic trauma is associated with high mortality rates. We report the case of a 24-year-old man who presented with a self-inflicted abdominal aortic penetration injury, resulting in a pseudoaneurysm. Rather uniquely, he was managed through prophylactic stenting to his abdominal aorta; this case was also rare in that there were remarkably no associated visceral injuries. Stenting was preferred because of risks of an aortic graft in a young man. A 14-mm Atrium Advanta™ stent was deployed, and angiography confirmed adequate exclusion of the pseudoaneurysm. He had no complications at follow-up.

The aetiology, clinical presentations and outcome of febrile encephalopathy in children in Papua New Guinea.

BACKGROUND: Febrile encephalopathy, defined as fever, seizures and/or altered consciousness, is a common presentation in children in tropical developing countries. Outcomes range from complete recovery through varying degrees of neurological disability which slowly resolve or remain permanent to death from either the acute illness or complications. Whilst bacterial meningitis accounts for a proportion of children affected, the aetiology in many remains unclear but includes malaria and probably viral encephalitis. AIM: To understand the aetiology, presentation and outcome of febrile encephalopathy in children in Papua New Guinea. METHODS: Children aged between 1 month and 12 years presenting to Port Moresby General Hospital with febrile encephalopathy were studied prospectively. A detailed history and examination and the following laboratory investigations were undertaken as appropriate: cerebrospinal fluid (CSF) microscopy and bacterial culture, gram stain, measurement of protein and glucose and latex agglutination testing for Haemophilus influenzae, Streptococcus pneumoniae and Neisseria meningitides; Ziehl-Neelsen staining and india ink examination on selected samples; IgM for Japanese encephalitis, dengue, rubella and measles; PCR testing and mycobacterial culture for Mycobacterium tuberculosis. Blood was tested for flavivirus, measles and rubella IgM and IgG. RESULTS: 149 children were enrolled in the study. 129 had a lumbar puncture and CSF examination; 66 had a normal CSF white cell count. A clinical or laboratory-based diagnosis was possible for 140 children, but a definite pathogen was identifiable for only 55 (37%). The diagnoses included bacterial meningitis in 33 (S. pneumonia 16, H. influenza 13 and N. meningitides 4), tuberculous meningitis (5), probable tuberculous meningitis (18), malaria (10), cryptococcal meningitis (1), flavivirus encephalitis (5), rubella encephalitis (1), hepatic encephalopathy (1) and HIV encephalopathy (1). There were 28 cases of meningitis of unspecified aetiology. Of the five children with IgM-confirmed flavivirus encephalitis, one had dengue serotype 1 and two had Japanese encephalitis. Twenty-five children (including three of the five children with CSF flavivirus IgM) had serological IgG evidence of previous flavivirus infection. A history of multiple convulsions, the presence of neck stiffness and use of the Glasgow coma score (GCS) and TB score chart helped to identify children with bacterial meningitis and an adverse outcome and those with febrile convulsions. CONCLUSION: The study confirms the importance of S. pneumonia and H. influenza as major causes of febrile encephalopathy in children in Papua New Guinea. Flaviviruses including Japanese encephalitis are a cause of the febrile encephalopathy syndrome, as is Mycobacterium tuberculosis. All children with febrile encephalopathy should have their GCS and TB scores recorded and should be examined for neck stiffness, and a history of the frequency of convulsions should be recorded. These basic clinical data can help to discriminate aetiology, to guide treatment and monitoring and to identify the children at highest risk of adverse outcome.

Seroepidemiology as basis for design of a human papillomavirus vaccination program.

We have performed a serological survey of HPV type 16-antibody prevalence by age and sex in Sweden and used it as a basis for modelling the optimal vaccination strategies in this population. Samples of 3,317 subjects were tested for HPV16-specific antibodies. The observed age-specific seroprevalences along with sexual behaviour data were used to infer parameter values for a mathematical model representing Sweden and the preventive effect of possible strategies estimated. By the year 2055, vaccination of females starting at age 12 in 2008 was most efficient, estimated to prevent 5.8 million cumulative HPV16 infections. Catch-up programs had a strong additional preventive effect. Vaccination also targeting males increased protective effect by about 4%, but had lower preventive effect per vaccination given. Addition of an HPV serosurvey to existing models and data has enabled us to estimate effect of different vaccination strategies, optimized to the HPV epidemiology in our population.

Two oscillators might control the locomotor activity rhythm of the high-altitude Himalayan strain of Drosophila helvetica.

The properties of the pacemaker controlling the adult locomotor activity rhythm of the high-altitude Himalayan (haH) strain (Hemkund Sahib, 4121 m above sea level) of Drosophila helvetica are strikingly different from those of the low-altitude Himalayan (laH) strain (Birahi, 1132 m above sea level) of the same species. The haH strain has a unimodal activity pattern with a delayed peak occurring about 4.5 h after lights-on of the entraining light-dark (LD) cycle, while the laH strain has a bimodal activity pattern with the morning and evening peaks. It is rather unusual for a wild type strain of any Drosophila species to have a unimodal activity pattern during entrainment as observed in the haH strain. The single activity peak of the haH strain is regarded as a consequence of delayed morning peak merging with the evening one. Three experiments were performed to test this hypothesis. The first experiment examined whether the single activity peak could be dissociated into two components by LD cycles in which photoperiods varied from 10 to 16 h per 24 h. The haH strain again exhibited a unimodal activity pattern with a delayed peak in 10, 12, and 14 h photoperiods but a bimodal activity pattern in 16 h photoperiod. The laH strain had bimodality in 10 and 12 h photoperiods, unimodality in a 14 h photoperiod, but complete arrhythmicity in a 16 h photoperiod. In the second experiment, the haH flies were transferred from LD 16:8 to LL at 5 lux to confirm whether the bimodality of this strain in LD 16:8 cycles was not the result of masking by the long photoperiod of 16 h. Bimodality of the haH strain persisted in LL too; moreover, the morning component free-ran with period (tau) <24 h, while the evening component free-ran with tau>24 h. The third experiment examined the LL-induced splitting of activity peak of the haH strain. Flies were transferred from LD 12:12 cycles to LL at 0, 1, 5, and 15 lux. The haH strain was rhythmic in LL at 0 and 1 lux with a unimodal activity pattern. It was also rhythmic in LL at 5 lux, but the single activity peak was split into two discrete components; the morning component free-ran with tau<24 h, while the evening component free-ran with tau>24 h. This strain, however, was completely arrhythmic in LL at 15 lux. The laH strain was uniformly arrhythmic in LL at all levels of light intensity. These results suggest that the single but late activity component of the haH strain during entrainment appears to be the consequence of merging the delayed morning peak with the evening one as an adaptation to the environmental conditions at the altitude of origin of this strain, where these flies begin activity in the forenoon owing to non-permissible low temperature in the morning.

Altitudinal variation in phase response curves for the Himalayan strains of Drosophila helvetica.

In previous research, it was determined that the altitude of origin altered the parameters of photic entrainment and free-running rhythmicity of adult locomotor activity of the high-altitude Himalayan (haH) strain (Hemkund-Sahib, 4121 m above sea level) of Drosophila helvetica compared to the low-altitude Himalayan (laH) strain (Birahi, 1132 m above sea level) of the same species. The present study investigated whether the altitude of origin also affects the parameters of the light pulse phase response curve (PRC) of the adult locomotor activity rhythm of the haH strain. Light pulse PRCs were determined for both strains against the background of constant darkness. Although both were "weak" or type 1 PRCs, the PRC for the haH strain differed from that of the laH strain in three basic parameters. The PRC for the haH strain was of low amplitude, had a protracted dead zone, and showed a ratio of the advance to delay region (A/D>1), while the PRC of the laH strain was characterized by high amplitude, absence of dead zone, and a A/D ratio<1. The asymmetric PRCs of these strains might explain the process of photic entrainment to 24 h light-dark cycles, as the long period of the free-running rhythm (tau) of the haH strain is complemented with a larger advance portion of its PRC (A/D>1), whereas the short tau of the laH strain is matched with a larger delay portion of its PRC (A/D<1). Prolonged dead zone and low amplitude in the PRC of the haH strain imply that the photic sensitivity of this strain has been drastically diminished as an adaptation to environmental conditions at the altitude of its origin. While adults of this strain begin activity in very bright light in the forenoon due to non-permissible low temperature in the morning, the converse is true for the laH strain.

Strategies for the introduction of human papillomavirus vaccination: modelling the optimum age- and sex-specific pattern of vaccination in Finland.

Phase III trials have demonstrated the efficacy of human papillomavirus (HPV) vaccines in preventing transient and persistent high-risk (hr) HPV infection and precancerous lesions. A mathematical model of HPV type 16 infection and progression to cervical cancer, parameterised to represent the infection in Finland, was used to explore the optimal age at vaccination and pattern of vaccine introduction. In the long term, the annual proportion of cervical cancer cases prevented is much higher when early adolescents are targeted. Vaccinating against hr HPV generates greater long-term benefits if vaccine is delivered before the age at first sexual intercourse. However, vaccinating 12 year olds delays the predicted decrease in cervical cancer, compared to vaccinating older adolescents or young adults. Vaccinating males as well as females has more impact on the proportion of cases prevented when vaccinating at younger ages. Implementing catch-up vaccination at the start of a vaccination programme would increase the speed with which a decrease in HPV and cervical cancer incidence is observed.

Altitudinal variation in the circadian rhythm of oviposition in Drosophila ananassae.

The effect of altitude on four basic properties of the pacemaker controlling the circadian rhythm of oviposition in two strains of Drosophila ananassae was determined. The high altitude (HA) strain from Badrinath (5123 m above sea level) had a low amplitude peak in the forenoon while the low altitude (LA) strain from Firozpur (179 m a.s.l.) had a high amplitude peak after the lights-off of LD 12:12 cycles. Free running periods in continuous darkness were about 22.6 and 27.4 h in the HA and LA strains, respectively. The light pulse phase response curve (PRC) for the HA strain showed a low amplitude and a dead zone of 8h; the ratio for the advance to delay region (A/D) was less than 1, while the PRC for the LA strain had a high amplitude, which was devoid of a dead zone and showed a ratio of A/D > 1. The magnitude of the delay phase shifts at CT 18 evoked by light pulses of 1 h duration, but varying light intensity was significantly different in the HA and LA strain, which suggests that the photic sensitivity of the clock photoreceptors mediating the phase shifts had been affected by the altitude.

Effects of temperature, photoperiod, and light intensity on the eclosion rhythm of the high-altitude Himalayan strain of Drosophila ananassae.

Eclosion rhythm of the high-altitude Himalayan strain of Drosophila ananassae from Badrinath (altitude 5123 m) was temperature-dependent and at 21 degrees C, it was entrained by cycles of 12h light: 12h darkness (LD 12:12) and free-ran in constant darkness, however, it was arrhythmic at 13 degrees C or 17 degrees C under identical experimental conditions (Khare, P. V., Barnabas, R. J., Kanojiya, M., Kulkarni, A. D., Joshi, D. S. (2002). Temperature dependent eclosion rhythmicity in the high altitude Himalayan strains of Drosophila ananassae. Chronobiol. Int. 19:1041-1052). The present studies were designed to see whether or not these strains could be entrained at 13 degrees C, 17 degrees C, and 21 degrees C by two types of LD cycles in which the photoperiod at 100 lux intensity varied from 6h to 18h, and the light intensity of LD 14:10 cycles varied from 0.001 lux to 1000 lux. All LD cycles entrained this strain at 21 degrees C but not at 13 degrees C or 17 degrees C. These results demonstrate that the entrainment of eclosion rhythm depends on the ambient temperature and not on the photoperiod or light intensity of LD cycles. Thus the temperature has taken precedence over the light in the entrainment process of eclosion rhythm of the high altitude Himalayan strain of D. ananassae. This may be the result of natural selection in response to the environmental temperature at Badrinath that resembles that of the sub-Arctic region but the photoperiod or light intensity are of the subtropical region.

The predicted effect of changes in cervical screening practice in the UK: results from a modelling study.

In 2003, the National Health Service Cervical Screening Programme (NHSCSP) announced that its screening interval would be reduced to 3 years in women aged 25-49 and fixed at 5 years in those aged 50-64, and that women under 25 years will no longer be invited for screening. In order to assess these and possible further changes to cervical screening practice in the UK, we constructed a mathematical model of cervical HPV infection, cervical intraepithelial neoplasia and invasive cervical cancer, and of UK age-specific screening coverage rates, screening intervals and treatment efficacy. The predicted cumulative lifetime incidence of invasive cervical cancer in the UK is 1.70% in the absence of screening and 0.77% with pre-2003 screening practice. A reduction in lifetime incidence to 0.63% is predicted following the implementation of the 2003 NHSCSP recommendations, which represents a 63% reduction compared to incidence rates in the UK population if it were unscreened. The model suggests that, after the implementation of the 2003 recommendations, increasing the sensitivity of the screening test regime from its current average value of 56 to 90% would further reduce the cumulative lifetime incidence of invasive cervical cancer to 0.46%. Alternatively, extending screening to women aged 65-79 years would further reduce the lifetime incidence to 0.56%. Screening women aged 20-25 years would have minimal impact, with the cumulative lifetime incidence decreasing from 0.63 to 0.61%. In conclusion, the study supports the 2003 recommendations for changes to cervical screening intervals.

The potential role of suppressive therapy for sex partners in the prevention of neonatal herpes: a health economic analysis.

BACKGROUND: The development of suppressive therapy and type specific tests for herpes infections allow for screening to reduce the risk of neonatal herpes. OBJECTIVES: To assess the potential effectiveness, cost effectiveness, and benefit of suppressive therapy among herpes simplex virus serodiscordant sex partners during pregnancy. METHODS: Decision and economic analyses are used to compare the incidence and costs of neonatal herpes in California (2000) for three interventions: (1) no management; (2) current guidelines (caesarean delivery for women with lesions); (3) screening for women at risk and use of suppressive treatment in sex partners. RESULTS: Screening and suppressive therapy are the most effective interventions, while current guidelines have limited effectiveness, but the latter provide the most cost effective results. CONCLUSIONS: While current guidelines are cost saving, they forgo a potential 82% decrease in neonatal herpes incidence that would be possible with screening and suppressive therapy if society were willing to pay the necessary US$363 000 per case prevented. To evaluate HSV screening and drug therapy completely, clinical trials and an economic assessment of infant mortality "value" to society are required.

Temperature dependent eclosion rhythmicity in the high altitude Himalayan strains of Drosophila ananassae.

The circadian pacemaker controlling the eclosion rhythm of the high altitude Himalayan strains of Drosophila ananassae captured at Badrinath (5123 m) required ambient temperature at 21 degrees C for the entrainment and free-running processes. At this temperature, their eclosion rhythms entrained to 12h light, 12h dark (LD 12:12) cycles and free-ran when transferred from constant light (LL) to constant darkness (DD) or upon transfer to constant temperature at 21 degrees C following entrainment to temperature cycles in DD. These strains, however, were arrhythmic at 13 or 17 degrees C under identical experimental conditions. Eclosion medians always occurred in the thermophase of temperature cycles whether they were imposed in LL or DD; or whether the thermophase coincided with the photophase or scotophase of the concurrent LD 12:12 cycles. The temperature dependent rhythmicity in the Himalayan strains of D. ananassae is a rare phenotypic plasticity that might have been acquired through natural selection by accentuating the coupling sensing mechanism of the pacemaker to temperature, while simultaneously suppressing the effects of light on the pacemaker.

Aging alters properties of the circadian pacemaker controlling the locomotor activity rhythm in males of Drosophila nasuta.

Effects of aging on the circadian rhythm of locomotor activity in males of Drosophila nasuta were investigated. The adult life of males was divided in 1-3 stages according to spontaneous changes in free-running period tau in constant darkness (DD): stage 1, days 1-19; stage 2, days 20-36; stage 3, days 37-43. Stage 1 was characterized by a bimodal activity pattern with a short light-induced morning peak and a prolonged evening peak when the flies were entrained to light-dark cycles of 12 hours of light, 12 hours of darkness (LD 12:12). The morning peak had a phase angle difference psi m (psi, the time from lights on in LD 12:12 cycles to the onset of morning peak) of about 0.1 h, while psi e (psi of evening peak) was about 9 h at stage 1. The transient morning peak was curtailed at the end of stage 1. At stage 2, the psi e was about 10 h, and the activity end was delayed by an addition of about 3 h of activity in the scotophase. The changes in tau during DD free runs were determined in two groups of flies: flies reared in LD 12:12 and flies reared in DD. In both groups, tau increased from about 23 h at stage 1 to about 25 h at stage 2. Stage 3 was characterized by arrhythmicity associated with highest mean activity level (total number of passes/fly/day) in the entrained and both free-running groups. The mean activity level increased significantly from stage 1 to stage 3 in all three groups of flies.