Five-Fraction Stereotactic Radiation for Head and Neck Paragangliomas

PURPOSE/OBJECTIVE(S)

Paragangliomas of the head and neck (HN) are benign, slow-growing neoplasms that are rarely functional. Treatment is often indicated for patients presenting with mass effect, cranial neuropathies, or pulsatile tinnitus. Radiotherapy, traditionally conventionally fractionated, is often used for primary, post-operative, and salvage therapy, given its excellent control rates and reduced risks to adjacent neurovascular structures. Stereotactic ablative radiation (SAbR) offers shorter treatment time, and modern techniques eliminate margins to improve organ-at-risk avoidance. SAbR may offer additional radiobiological sparing of normal structures over single-fraction SAbR. We aimed to evaluate tumor and symptom response, acute and late toxicity rates, and recurrence patterns in HN paraganglioma patients treated with 25 Gy in 5 fractions.

MATERIALS/METHODS

Retrospective chart review collected baseline patient and tumor information, treatment and dosimetry details, acute and long-term toxicity grades (per the CTCAE v. 5.0), symptom and tumor response, and survival. Local control was defined as the absence of local enlargement (per RECIST v. 1.1) or marginal failure and was estimated using the Kaplan-Meier method.

RESULTS

Between December 2009-March 2020, 39 patients received 25 Gy in 5 fractions to 43 HN paragangliomas, of which 17 were treated in 11 patients with hereditary paraganglioma-pheochromocytoma syndrome. Fifteen targets were post-operative recurrent or residual tumors. There were 27 jugulotympanic tumors, 4 jugular, 1 tympanic, 8 vagal, 5 carotid body, and 2 jugulotympanic or vagal. Median follow-up time was 3.3 years (range 0-11.4 years), and 21 targets had at least 4 years of follow-up. Tumor volume decreased by a median of 37%. Three-year local control was 100%. One patient, known to harbor an SDHD mutation, had 2 out-of-field recurrences within the post-operative bed at 7.1 years. Two patients experienced 2 marginal recurrences within the post-operative bed at 6.1 and 8.4 years: one had an SDHB mutation and developed metastatic disease, and the other did not have genetic testing. The most common grade 1-2 acute toxicities were headache and fatigue; the most common grade 1-2 late toxicities were dysphagia and otalgia. There were no grade >2 acute toxicities. A late grade 3 aspiration event was seen in 1 patient who presented with paralyzed vocal cord requiring multiple medialization laryngoplasties. Within 6 months of SAbR, 18% of symptoms or toxicities improved or resolved; 34% improved or resolved more than 6 months after SAbR.

CONCLUSION

This is the largest series of HN paragangliomas treated with SAbR, detailing a 10-year experience with a 5-fraction regimen that is well-tolerated and achieves excellent local control. Post-SAbR recurrences occurred outside of the radiation field but within the post-operative bed, suggesting that some post-operative patients may benefit from expanded radiation volumes or close surveillance for salvage therapy.

Women’s experiences of accessing vaccines during pregnancy and for their babies during COVID-19

Background

COVID-19 changed access to healthcare, including vaccinations, in the United Kingdom (UK). This study explored UK women’s experiences of accessing pertussis vaccination during pregnancy and infant vaccinations during COVID-19.

Methods

An online cross-sectional survey was completed, between 3rd August-11th October 2020, by 1404 women aged 16+ years who were pregnant at some point after the first UK lockdown from March 23rd 2020. Ten follow-up semi-structured interviews were conducted.

Results

Most women surveyed were pregnant (65.7%) and a third postnatal (34.3%). Almost all women (95.6%) were aware that pertussis vaccination is recommended in pregnancy. Most pregnant (72.1%) and postnatal women (84.0%) had received pertussis vaccination however, access issues were reported. Over a third (39.6%) of women had a pregnancy vaccination appointment changed. COVID-19 made it physically difficult to access pregnancy vaccinations for one fifth (21.5%) of women and physically difficult to access infant vaccinations for almost half of women (45.8%). Nearly half of women (45.2%) reported feeling less safe attending pregnancy vaccinations and over three quarters (76.3%) less safe attending infant vaccinations due to COVID-19. The majority (94.2%) felt it was important to get their baby vaccinated during COVID-19. Pregnant women from ethnic-minorities and lower-income households were less likely to have been vaccinated. Minority-ethnicity women were more likely to report access problems and feeling less safe attending vaccinations for both themselves and their babies. Qualitative analysis found women experienced difficulties accessing antenatal care and relied on knowledge from previous pregnancies to access vaccine appointments.

Conclusions

COVID-19 disrupted access to vaccinations in the UK. Vaccine services must ensure equitable access to vaccine appointments during ongoing and future pandemics including tailoring services for lower income and ethnic minority families.

Key messages

• Pregnancy and infant vaccines was disrupted by COVID-19 with women feeling less safe and having difficulties accessing vaccinations with ethnic minority women more likely to report access issues.

• Equitable access to routine pregnancy and infant vaccine appointments must be prioritised during future pandemics, including considering tailoring services for different population groups.

Impact of hydraulic retention time on phosphorus removal from wastewater using reactive media

Phosphorus (P) discharge from wastewater treatment plants into the environment contributes to eutrophication issues. Reactive media filters represent an effective, simple and cost-effective solution to decrease the P content. Previous research used various experimental designs and often synthetic wastewater, making assessment of real-world performance difficult. This study assesses the impact of the hydraulic retention time (HRT) on P removal using real wastewater to refine design criteria for full-scale installations. Four media were compared in column experiments for >200 days. Different HRTs were applied and initially the media achieved low P effluent concentrations of >0.1 mg/L PO₄-P, increasing over time. Best P removal was observed for the highest HRT with on average >99%. HRT was seen to be the driving factor for P removal rather than media capacity. Three of the four materials showed pH levels above 12 initially, decreasing over time. Water quality parameters, including organics, solids and metals, were monitored. In-depth analysis confirmed formation of calcium phosphate precipitation on the media's surface. The results suggest the importance of an optimal HRT to achieve high P removal and show that the reactive media application is an appropriate technology for P removal on small sites if the elevated pH is addressed.

Analysis of Milk-Based Infant Formula. Phase IV. Iodide, Linoleic Acid, and Vitamins D and K: U.S. Food and Drug Administration-Infant Formula Council: Collaborative Study

In 1982, the U.S. Food and Drug Administration, the Infant Formula Council and its member companies, contract laboratories, and other government laboratories began a study of analytical methods for the nutrients listed in the Infant Formula Act of 1980. Phases I, II, III, and V have been completed. The present report provides data on Phase IV, in which 13 laboratories collaboratively studied an ion-selective electrode method for analyzing iodide, a gas chromatographic method for linoleic acid, and 2 liquid chromatographic (LC) methods each for vitamins D and K. Data were insufficient to evaluate one each of the LC methods studied for vitamins K and D. The relative standard deviations (RSD) are sufficient for the nutrient levels found in infant formula. RSDs (%) for repeatability (RSDr) and reproducibility (RSDR), respectively, were as follows: iodide, 4.0-11.4 and 13.5-18.2; linoleic acid, 1.0-1.6 and 3.5-5.1; vitamin K1, 3.2-16.0 and 6.2-19.4; and vitamin D3,4.2 and 35.0. The recommendation to adopt the method for vitamin D was supported by the results of a ministudy. All laboratories were capable of using these methods with little training. The methods for determination of iodide, linoleic acid, and vitamins D and K in ready-to-feed milkbased infant formula have been adopted first action by AOAC International.

Considerations for the Perioperative Care of Elderly and Frail Patients

The number of elderly patients undergoing anesthesia is increasing. At the same time aging is associated with decreased functional reserve of all major organ systems and an increase in comorbid conditions, requiring a comprehensive perioperative evaluation to minimize morbidity and mortality. The preoperative assessment should focus on the risk/benefit analysis vis-à-vis the proposed intervention, allowing the practitioner to adapt surgical and anesthetic care, as well optimize health and functional status. In addition to the usual evaluation for cardiac and pulmonary risk, the preoperative assessment in the older patient should also address the risk of postoperative cognitive dysfunction and delirium. 'Do-not-resuscitate' orders must be clarified with the patients or substitute decision maker. Studies have not been able to clearly show the superiority of one anesthetic approach for the geriatric patient, although there are probably advantages to using regional anesthetic techniques. Overall the patient's preoperative functional status along with the proposed intervention is the primary determinants of the patient's long term functional outcome and wellbeing. The elderly patient may be at his most vulnerable during the postoperative phase, and a relatively high frequency of adverse events in the elderly, including respiratory insufficiency, myocardial and cerebrovascular ischemia, renal failure, infectious complications as well as delirium and postoperative cognitive dysfunction have been observed. Perioperative interventions should target modifiable risk factors and the avoidance of even minor complications with an ultimate goal of improving long-term outcome.

Marantic endocarditis presenting with multifocal neurological symptoms

Non-bacterial thrombotic endocarditis (NBTE), also known as marantic endocarditis, has been reported to occur in 0.3-9.3% of the adult population at autopsy. NBTE associated with malignancy is an underrecognised cause of thromboembolic disorders. The clinical spectrum encountered and investigation results can be non-specific, often mimicking other acute conditions such as infective endocarditis. We describe the case of a 34-year-old woman with non-localising and multifocal neurological symptoms, who was subsequently diagnosed with NBTE secondary to a resectable primary lung adenocarcinoma.

Prevalence of Dirofilaria immitis (Nematoda: Filarioidea) in mosquitoes from northeast Arkansas, the United States

A mosquito survey was conducted to identify which species of mosquitoes carry Dirofilaria immitis (Leidy) (Nematoda: Filarioidea), dog heartworm, in northeast Arkansas. Using polymerase chain reaction, mosquitoes were analyzed for D. immitis, Dirofilaria repens Railliet & Henry, and Acanthocheilonema dracunculoides Cobbold. Mosquitoes were collected from April to October 2009 using black light ultraviolet traps baited with dry ice. Sixteen mosquito species were identified. D. immitis was identified in nine mosquito species, which included Aedes vexans (Meigen), Anopheles quadrimaculatus Say, Anopheles punctipennis (Say), Culex pipiens quinquefasciatus Say, Culex erraticus (Dyer & Knab), Culiseta inornata (Williston), Psorophora columbiae (Dyer & Knab), Psorophora ferox (Humboldt), and Psorophora howardii Coquillett. No D. repens or A. dracunculoides DNA was amplified. Of the 1,212 mosquito pools tested, 7.3% were positive for D. immitis. Frequency of D. immitis infections from six collection sites ranged from 2.1 to 19.4%. Ae. vexans and An. quadrimaculatus were the two most abundant species, composing 58.7 and 23.7% of the total mosquitoes collected, with 9.6 and 6.9% of pools positive for D. immitis, respectively. To investigate localized vector infection rates of D. immitis, mosquitoes were collected from inside the kennel of a heartworm-positive dog. Of the 114 mosquitoes collected, 84 (73.7%) were positive for D. immitis. The frequency of D. immitis-infected mosquitoes collected near a heartworm-positive dog was considerably higher than in the original six collection sites, suggesting a single heartworm-positive dog potentially increases infection pressure on susceptible animals sharing mosquito exposure.

Using graded motor imagery for complex regional pain syndrome in clinical practice: failure to improve pain

BACKGROUND

There is good evidence from studies conducted in a single-centre research setting for the efficacy of graded motor imagery (GMI) treatment, a complex physiotherapy intervention, to reduce pain in long-standing complex regional pain syndrome (CRPS). However, whether GMI is effective in clinical practice is not established.

AIM

To establish whether GMI is effective in clinical practice.

METHODS

We undertook a prospective audit of GMI treatment at two UK centres with a special interest in the management of patients with CRPS. All patients received GMI, in conjunction with a range of other 'best practice' physical and psychological interventions.

RESULTS

The patients' average pain intensities did not improve with treatment [centre 1: n = 20, pre-post numeric rating scale (NRS) difference 0.6 [confidence interval (CI) -0.3 to 1.5]; centre 2: n = 12, pre-post NRS difference 0.2 (CI: -0.9 to 1.2)]. Patients at centre 1 reported significant functional improvement. Improved performance on left/right judgement replicated in both centres seen in the clinical trials.

CONCLUSIONS

The failure of our real-world implementation of GMI suggests that better understanding of both the GMI methodology and its interaction with other treatment methods is required to ensure that GMI research results can be translated into clinical practice. Our results highlight challenges with the translation of complex interventions for chronic pain conditions into clinical practice.

Independent health care: using a board-to-ward approach to achieve improvement in infection prevention standards

The Health and Social Care Act 2008 places a legal responsibility upon healthcare organisations to provide a clean environment where infection risks are minimised. From April 2010, the regulation of both the NHS and the independent healthcare sector will, for the first time, fall under the same legislative framework. Nuffield Health (NH) is an independent healthcare provider with 30 acute hospitals. Strategic management of infection prevention is led by the NH Director for Infection Prevention. Management at the hospital level is led by the matron/Director for Infection Prevention and Control supported by trained infection prevention link practitioners (IPLPs). High-quality infection prevention across a large geographical area presents many challenges and IPLPs have been used to both monitor and improve the quality of infection prevention using national audit tools and acting as role models to influence practice. Audit results over 4 years demonstrate yearly improvements and low rates of healthcare-associated infections.

Minimal contribution of desmethyl-gefitinib, the major human plasma metabolite of gefitinib, to epidermal growth factor receptor (EGFR)-mediated tumour growth inhibition

Desmethyl-gefitinib is a major metabolite of gefitinib observed in human plasma at concentrations similar to those of gefitinib. The epidermal growth factor receptor (EGFR)-related inhibitory effects of gefitinib and desmethyl-gefitinib have been compared both in vitro, using enzyme kinase assays and tumour cell growth inhibition, and in vivo by assessment of tumour xenografts growth inhibition in the mouse. Both gefitinib (IC(50) = 0.022 microM) and its desmethyl metabolite (0.036 microM) inhibited subcellular EGFR tyrosine kinase activity with a similar potency and selectivity. However, desmethyl-gefitinib (IC(50) = 0.76 microM) was 15 times less active than gefitinib (0.049 microM) against EGF-stimulated KB cell growth in a whole cell assay. Following a preliminary pharmacokinetic study to compare apparent oral bioavailability, gefitinib (75 mg kg(-1)) and desmethyl-gefitinib (150 mg kg(-1)) were administered orally for 15 days to female nude mice bearing LoVo tumour xenografts. Tumour concentrations of gefitinib (AUC = 300 microg h g(-1)) were much higher than those of desmethyl-gefitinib (44.3 microg h g(-1)), although plasma concentrations of gefitinib (48.4 microg h ml(-1)) and desmethyl-gefitinib (39.0 microg h ml(-1)) were quite similar at these dose levels. Gefitinib produced significant tumour growth inhibition throughout the course of the study ultimately resulting in a 50% decrease (compared with controls) by day 15. In contrast, although present at comparable plasma levels, desmethyl-gefitinib had little effect on tumour growth and is, therefore, considered unlikely to contribute significantly to the therapeutic activity of gefitinib in the clinical situation.

Efficacy of a single application of a 12.5% pyriprole topical solution against laboratory infestations with ticks (Ixodes ricinus, Dermacentor reticulatus, and Rhipicephalus sanguineus) on dogs

In three separate studies, the efficacy of a single treatment with a 12.5% pyriprole spot-on solution was investigated against induced infestation with Ixodes ricinus, Dermacentor reticulatus and Rhipicephalus sanguineus on dogs (both sexes; Beagles in Studies 1 and 2, mixed-breed in Study 3). For each tick species, one group of 8 dogs left untreated (Studies 1 and 2) or treated with a placebo solution (Study 3) was compared with another group treated once with the spot-on solution at a dose rate of at least 12.5mg/kg. The dogs were infested with 50 unfed adult ticks of the respective species at various time-points before and after treatment and the surviving attached and unattached ticks were recorded 48 h after re-infestation. For each tick species, efficacy was assessed for each time-point and cumulatively for the whole evaluation period. The dogs were submitted to general health observations and clinical assessments during the study. Efficacy against I. ricinus and R. sanguineus was 100% during the whole evaluation period of 30 days. For D. reticulatus cumulative efficacy for the 30 days after treatment was 98.9%. The product was well tolerated by all the animals.

Efficacy of pyriprole topical solution against the cat flea, Ctenocephalides felis, on dogs

Three studies evaluating various aspects of the performance of pyriprole against the cat flea, Ctenocephalides felis, on dogs demonstrated that 12.5% pyriprole applied as a spot-on provides rapid, long-lasting efficacy against adult cat fleas, even under severe flea challenge. Speed of kill data indicate treatment with this product can interrupt an already established adult flea infestation, whereas monthly treatment can prevent reinfestation. Pyriprole disrupts the flea life cycle by killing adult fleas before they lay eggs for at least 30 days after treatment. The residual effect of pyriprole on debris from treated dogs (dander, hair, scales, and flea feces) resulted in a decreased ability of cat flea larvae to complete development to the adult stage for 2 weeks after application. Based on the results of these studies, 12.5% pyriprole represents a valuable new tool in the control of the cat flea, C. felis, on dogs.

The effect of water and shampooing on the efficacy of a pyriprole 12.5% topical solution against brown dog tick (Rhipicephalus sanguineus) and cat flea (Ctenocephalides felis) infestations on dogs

The efficacy of a single treatment with a 12.5% pyriprole spot-on formulation against induced infestations with R. sanguineus ticks and cat fleas (C. felis) as well as its persistence after repeated washing and shampooing was investigated in four separate studies. In a first study on R. sanguineus involving 32 beagle dogs, the efficacy at various time-points during the 30 days that followed treatment assessed 48 h after re-infestation ranged from 100% to 99.3%. No engorged ticks, alive or dead, were found in the treated animals. Shampooing 2 days after treatment and weekly washings did not affect the efficacy. In a second study on R. sanguineus involving 32 beagle dogs, the efficacy at various time-points during the 30 days that followed treatment assessed 48 h after re-infestation ranged from 100% to 96.8%. Single washing 8h after treatment and single shampooing 24 h after treatment had no negative impact on the efficacy of the product. In a third study on C. felis involving 28 beagle dogs, the efficacy at various time-points during the 30 days that followed treatment assessed 48 h after re-infestation was always 100% and weekly washings did not diminish the efficacy. In a last study on C. felis involving 24 beagle dogs, the efficacy at various time-points during the 5 weeks that followed treatment assessed 48 h after re-infestation ranged from 100% to 99.8%, and shampooing 24 h after treatment did not reduce the efficacy. The product was well tolerated by the dogs.

Comparison of intranasal with targeted lymph node immunization using PR8-Flu ISCOM adjuvanted HIV antigens in macaques

The rapidly spreading HIV epidemic requires a vaccine that elicits potent mucosal immunity to halt or slow transmission. Induction of these responses will depend on the use of appropriate adjuvants and targeting of the mucosal immune system. Previously, immune stimulating complexes (ISCOM) have shown great potency as adjuvant in the induction of mucosal responses in mice and systemic responses in non-human primates. In this study, HIV formulated in PR8-Flu ISCOM adjuvant was applied to immunize rhesus macaques against HIV; targeting the mucosa either via intranasal (IN) application or via targeted lymph node immunization (TLNI). While, strong systemic, HIV specific, cytokine, lymphoproliferative, and antibody responses were induced via the TLNI route, the IN application generated only low responses. Furthermore, all four animals immunized via TLNI developed vaginal IgA antibodies against gp120. In conclusion, in contrast to what has been demonstrated in mice, the IN application of PR8-Flu ISCOM did not induce strong immune responses in rhesus macaques unlike those immunized by the TLNI route.

Maternal and newborn-care practices during pregnancy, childbirth, and the postnatal period: a comparison in three rural districts in Bangladesh

The aim of this study was to examine the prevalence of maternal and newborn-care practices among women reporting a birth in the previous year in three districts in different divisions of Bangladesh. In 2003, 6,785 women, who had delivered a newborn infant in the previous year, across three districts in Bangladesh, were interviewed. Overall, less than half of the women received any antenatal care, and 11% received a minimum of four check-ups. Only 18% took iron tablets for at least four months during pregnancy. Over 90% of the 6,785 deliveries took place at home, and only 11% were attended either by a doctor or by a nurse. The mothers reported three key hygienic practices in 54% of deliveries: attendants washing their hands with soap and boiling cord-tie and blade for cutting the cord. Forty-four percent of the 6,785 infants were bathed immediately after delivery, and 42% were given colostrum as their first food. The results suggest that maternal and newborn-care remains a cause of concern in rural Bangladesh. Short-term policies to promote healthy behaviour in the home are needed, in addition to the long-term goal of skilled birth attendance.

Touch detection of neonatal hypothermia in Nepal

The use of touch by health workers to detect hypothermia was examined in 250 newborns in Nepal. Palpation of the feet shows fair interobserver agreement (kappa = 0.4-0.7) and high sensitivity (>80%) but low specificity (36%-74%) compared with axillary thermometry. Traditional birth attendants should feel an infant's feet to detect hypothermia.

Body shape and composition in HIV-infected women: an urban cohort

OBJECTIVES

Alterations in body shape and composition are associated with HIV/AIDS. Wasting remains prevalent; increasingly, lipodystrophy is reported. Obesity is also epidemic in the USA. In this study, we sought to characterize the body changes reported by women attending a US urban clinic, and to evaluate contributing factors using inexpensive methods that are readily available in clinical practice.

METHODS

In an urban Maryland clinic, a cross-section of HIV-infected women were evaluated by self report, anthropomorphic measurements, bioelectric impedance analysis (BIA) and chart review; they were categorized as no change, lipodystrophy, weight loss/wasting or weight gain/obesity.

RESULTS

One hundred and sixty-one women were evaluated: 144 (89%) were African-American; 100 (62%) had used intravenous drugs and 40 (25%) were actively injecting drugs, while 39 (24%) smoked crack. Ninety-five (59%) were on highly active antiretroviral therapy (HAART) for a median period of 11.7 months [interquartile range (IQR)=4.5-24.2]. Since starting current HAART or in the previous year, 12 (7.4%) reported lipodystrophy changes, 85 (52.8%) weight gain, 27 (16.8%) overall weight loss, and 37 (23.0%) no change. Lipodystrophy was associated with higher CD4 percentage (P=0.03), lower frequency of crack use (P=0.04) and higher educational level (P=0.03). Weight loss correlated with longer duration of infection (P=0.01), select BIA results and increased rate of crack use (P=0.005). Weight gain was associated with higher fat mass (P=0.005), higher peak viral load (P=0.02), and lower rate of intravenous drug use (P=0.03).

CONCLUSIONS

Self-reported changes in body shape were common. Obesity and complications of illicit drug use were more prevalent than lipodystrophy in this inner-city population of HIV-positive women.

Advanced anodes for high-temperature fuel cells

Fuel cells will undoubtedly find widespread use in this new millennium in the conversion of chemical to electrical energy, as they offer very high efficiencies and have unique scalability in electricity-generation applications. The solid-oxide fuel cell (SOFC) is one of the most exciting of these energy technologies; it is an all-ceramic device that operates at temperatures in the range 500-1,000 degrees C. The SOFC offers certain advantages over lower temperature fuel cells, notably its ability to use carbon monoxide as a fuel rather than being poisoned by it, and the availability of high-grade exhaust heat for combined heat and power, or combined cycle gas-turbine applications. Although cost is clearly the most important barrier to widespread SOFC implementation, perhaps the most important technical barriers currently being addressed relate to the electrodes, particularly the fuel electrode or anode. In terms of mitigating global warming, the ability of the SOFC to use commonly available fuels at high efficiency, promises an effective and early reduction in carbon dioxide emissions, and hence is one of the lead new technologies for improving the environment. Here, we discuss recent developments of SOFC fuel electrodes that will enable the better use of readily available fuels.

Efficacy and longevity of nitenpyram against adult cat fleas (Siphonaptera: Pulicidae)

Nitenpyram (Capstar) is a fast acting, orally administered flea treatment that is absorbed into the blood of the host animal and is readily available for uptake by feeding fleas. We examined the efficacy of a single dose of nitenpyram against adult cat fleas, Ctenocephalides felis (Bouché), over several days. We recorded adult flea mortality and flea egg production on treated and untreated cats. Nitenpyram provided 100% kill of all fleas on the host at the time of treatment and for up to 24 h after treatment. Between 24 and 48 h after treatment, there was a 98.6% reduction in adult flea numbers. From 48 to 72 h, there was a 5% reduction in adult fleas. There was a 97% reduction and 95.2% reduction in the number of flea eggs collected from treated versus untreated animals during the first 48 h and from 48 to 72 h, respectively. In addition, we quantified three distinct behavioral responses of infested adult cats treated with nitenpyram to determine the extent of any immediate, overt behavioral responses in treated animals. A significant increase in scratching, biting, licking, and twitching occurred for 5 h. The biting and licking continued for 7 h after treatment. Administration of nitenpyram provides an effective mechanism to eliminate adult fleas from hosts for up to 48 h after treatment.

Interrelations between three proxies of health care need at the small area level: an urban/rural comparison

STUDY OBJECTIVE

To examine the relations between geographical variations in mortality, morbidity, and deprivation at the small area level in the south west of England and to assess whether these relations vary between urban and rural areas.

DESIGN

A geographically based cross sectional study using 1991 census data on premature limiting long term illness (LLTI) and socioeconomic characteristics, and 1991-1996 data on all cause premature mortality. The interrelations between the three widely used proxies of health care need are examined using correlation coefficients and scatterplots. The distribution of standardised LLTI residuals from a regression analysis on mortality are mapped and compared with the distribution of urban and rural areas. Multilevel Poisson modelling investigates whether customised deprivation profiles improve upon a generic deprivation index in explaining the spatial variation in morbidity and mortality after controlling for age and sex. These relations are examined separately for urban, fringe, and rural areas.

SETTING

Nine counties in the south west of England.

PARTICIPANTS

Those aged between 0-64 who reported having a LLTI in the 1991 census, and those who died during 1991-1996 aged 0-74.

MAIN RESULTS

Relations between both health outcomes and generic deprivation indices are stronger in urban than rural areas. The replacement of generic with customised indices is an improvement in all area types, especially for LLTI in rural areas. The relation between mortality and morbidity is stronger in urban than rural areas, with levels of LLTI appearing to be greater in rural areas than would be predicted from mortality rates. Despite the weak direct relations between mortality and morbidity, there are strong relations between the customised deprivation indices computed to predict these outcomes in all area types.

CONCLUSIONS

The improvement of the customised deprivation indices over the generic indices, and the similarity between the mortality and morbidity customised indices within area types highlights the importance of modelling urban and rural areas separately. Stronger relations between mortality and morbidity have been revealed at the local authority level in previous research providing empirical evidence that the inadequacy of mortality as a proxy for morbidity becomes more marked at lower levels of aggregation, especially in rural areas. Higher levels of LLTI than expected in rural areas may reflect different perceptions or differing patterns of illness. The stronger relations between the three proxies in urban than rural areas suggests that the choice of indicator will have less impact in urban than rural areas and strengthens the argument to develop better measures of health care need in rural areas.

Video-assisted thoracoscopic thymectomy for myasthenia gravis

BACKGROUND

Thymectomy is an effective, but radical therapy for myasthenia. Video-assisted thoracic surgery (VATS) may allow a minimally invasive alternative to the standard sternotomy approach.

AIMS

To audit prospectively the outcome of VATS thymectomy for myasthenia gravis in a unit specializing in advanced VATS techniques.

METHODS

Twenty-six patients underwent VATS thymectomy between 1997 and 2001. Most underwent preoperative plasma exchange therapy. Seventeen women and nine men with a median age of 36 years (range 17-71 years) had a right-sided VATS approach to remove all anterior mediastinal fat and thymic tissue.

RESULTS

There was no perioperative mortality and all procedures were concluded successfully, with one patient requiring sternotomy. Twenty-five patients were extubated in theatre and one patient required 17 h of assisted ventilation. The other significant complication was a diathermy injury to the phrenic nerve, which recovered. Median postoperative stay was 4 days (range 2-6 days), with median postoperative chest drainage for 2 days (range 1-3 days). Three patients had progression of disease postoperatively. The remainder were asymptomatic (7), improved (14) or stable (2).

CONCLUSION

In a dedicated unit with neurological and intensive care support, VATS thymectomy is a safe, effective method of obtaining remission or improvement in myasthenia gravis (MG). While achieving the same surgical goal, this approach offers advantages of improved cosmesis, shorter recovery time and minimal chest wall disruption over the gold standard of sternotomy. Better patient acceptance of this minimally invasive technique may result in wider application of the benefits of thymectomy in MG.

Generalized epilepsy with febrile seizures plus: mutation of the sodium channel subunit SCN1B

Generalized epilepsy with febrile seizures plus (GEFS(+)) is an important childhood genetic epilepsy syndrome with heterogeneous phenotypes, including febrile seizures (FS) and generalized epilepsies of variable severity. Forty unrelated GEFS(+) and FS patients were screened for mutations in the sodium channel beta-subunits SCN1B and SCN2B, and the second GEFS(+) family with an SCN1B mutation is described here. The family had 19 affected individuals: 16 with typical GEFS(+) phenotypes and three with other epilepsy phenotypes. Site-specific mutation within SCN1B remains a rare cause of GEFS(+), and the authors found no evidence to implicate SCN2B in this syndrome.

Increasing the sophistication of access measurement in a rural healthcare study

This paper considers the problem of deriving realistic access measures between population demand and health service locations, in the context of a rural region of England. The paper reviews approaches used in earlier work by the authors and others, and considers new public transport information systems that are now becoming available. An application is presented which incorporates the modelling of both private and public transportation travel times for access to district general hospitals in Cornwall. This information has been assembled from published timetables in order to evaluate the use of more sophisticated access measures that might be used when such data becomes more generally available. The work is set within the context of an ongoing substantive research programme concerned with health outcomes in the rural South West of England.

Induction of potent immune responses by cationic microparticles with adsorbed human immunodeficiency virus DNA vaccines

The effectiveness of cationic microparticles with adsorbed DNA at inducing immune responses was investigated in mice, guinea pigs, and rhesus macaques. Plasmid DNA vaccines encoding human immunodeficiency virus (HIV) Gag and Env adsorbed onto the surface of cationic poly(lactide-coglycolide) (PLG) microparticles were shown to be substantially more potent than corresponding naked DNA vaccines. In mice immunized with HIV gag DNA, adsorption onto PLG increased CD8(+) T-cell and antibody responses by approximately 100- and approximately 1,000-fold, respectively. In guinea pigs immunized with HIV env DNA adsorbed onto PLG, antibody responses showed a more rapid onset and achieved markedly higher enzyme-linked immunosorbent assay and neutralizing titers than in animals immunized with naked DNA. Further enhancement of antibody responses was observed in animals vaccinated with PLG/DNA microparticles formulated with aluminum phosphate. The magnitude of anti-Env antibody responses induced by PLG/DNA particles was equivalent to that induced by recombinant gp120 protein formulated with a strong adjuvant, MF-59. In guinea pigs immunized with a combination vaccine containing HIV env and HIV gag DNA plasmids on PLG microparticles, substantially superior antibody responses were induced against both components, as measured by onset, duration, and titer. Furthermore, PLG formulation overcame an apparent hyporesponsiveness of the env DNA component in the combination vaccine. Finally, preliminary data in rhesus macaques demonstrated a substantial enhancement of immune responses afforded by PLG/DNA. Therefore, formulation of DNA vaccines by adsorption onto PLG microparticles is a powerful means of increasing vaccine potency.