Atomic layer deposition ultrathin film origami using focused ion beams

Focused ion beam (FIB) micromachining is a powerful tool for maskless lithography and in recent years FIB has been explored as a tool for strain engineering. Ion beam induced deformation can be utilized as a means for folding freestanding thin films into complex 3D structures. FIB of high energy gallium (Ga⁺) ions induces stress by generation of dislocations and ion implantation within material layers, which create creases or folds upon mechanical relaxation enabled by motion of the material layers. One limitation on such processing is the ability to fabricate flat freestanding thin film structures. This capability is limited by the residual stresses formed during processing and fabrication of the films, which can result in initial curvature and deformation of films upon release from a sacrificial fabrication layer. This paper demonstrates folding in freestanding ultrathin films (<40 nm thin) of heterogeneous composition (metal, insulator, semiconductor, etc) with large lateral dimension structures (aspect ratio >1:1000) by ion-induced stress relaxation. The ultrathin flat structures are fabricated using atomic layer deposition on sacrificial polyimide. We have demonstrated vertical folding with 30 keV Ga⁺ ions in structures with lateral dimensions varying from 10 to 50 μm.

Ultrathin thermoacoustic nanobridge loudspeakers from ALD on polyimide

The recent development of low-temperature (<200 °C) atomic layer deposition (ALD) for fabrication of freestanding nanostructures has enabled consideration of active device design based on engineered ultrathin films. This paper explores audible sound production from thermoacoustic loudspeakers fabricated from suspended tungsten nanobridges formed by ALD. Additionally, this paper develops an approach to lumped-element modeling for design of thermoacoustic nanodevices and relates the near-field plane wave model of individual transducer beams to the far-field spherical wave sound pressure that can be measured with standard experimental techniques. Arrays of suspended nanobridges with 25.8 nm thickness and sizes as small as 17 μm × 2 μm have been fabricated and demonstrated to produce audible sound using the thermoacoustic effect. The nanobridges were fabricated by ALD of 6.5 nm Al₂O₃ and 19.3 nm tungsten on sacrificial polyimide, with ALD performed at 130 °C and patterned by standard photolithography. The maximum observed loudspeaker sound pressure level (SPL) is 104 dB, measured at 20 kHz, 9.71 W input power, and 1 cm measurement distance, providing a loudspeaker sensitivity value of ∼64.6 dB SPL/1 mW. Sound production efficiency was measured to vary proportional to frequency f ³ and was directly proportional to input power. The devices in this paper demonstrate industrially feasible nanofabrication of thermoacoustic transducers and a sound production mechanism pertinent to submicron-scale device engineering.

Measurement of plasma renin concentration and angiotensin II in peripheral and renal venous plasma in the management of renovascular hypertension

Athough in general, measurement of renal vein renin appears to give a good prediction as to the subsequent response to surgery, its main value lies in its ability to reflect changes in renal plasma flow; true changes in renin secretion rate being much more difficult to detect. Although it is a little early to say how much information can be derived from saralasin infusions, caution must be exercised in necessarily assuming that the test accurately reflects subsequent surgical response.

Artemisia annua extracts, artemisinin and 1,8-cineole, prevent fruit infestation by a major, cosmopolitan pest of apples

CONTEXT

Extracts of Artemisia annua (L.) (Asteraceae) and artemisinins are used for treatment of malaria, parasitic infections and have potent anticancer properties in cell lines. Eucalyptus oil and 1,8-cineole have antimicrobial, immune-stimulatory, anti-inflammatory, antioxidant, analgesic, and spasmolytic effects. Codling moth, Cydia pomonella, (L.) (Tortricidae), is a major cosmopolitan pest of the apple, potentially causing damage translating to 40 billion US dollars per year, globally. Currently used control measures are either hazardous to agricultural workers and harmful to environment, or ineffective. The potential of plant-derived semiochemicals for codling moth control is heavily understudied.

OBJECTIVE

This study evaluated the potential of A. annua extracts, and two chemicals that this plant contains, artemisinin and 1,8-cineole, for preventing apple feeding and infestation by neonate Cydia pomonella larvae.

METHODS

We studied effects of A. annua extracts, artemisinin and 1,8-cineole on apple infestation by neonate codling moth larvae using fruit choice assay in laboratory experiments. Preference of fruit treated with test solutions versus fruit treated with solvent was recorded and analyzed.

RESULTS

Crude A. annua extracts prevented fruit feeding at 1, 3, and 10 mg/ml. Artemisinin had feeding deterrent effects at 10 and 30 mg/ml, and 1,8-cineole at 100 and 300 mg/ml.

DISCUSSION AND CONCLUSIONS

A. annua contains chemicals that prevent apple infestation by codling moth neonates. Artemisinin and 1,8-cineole are among them, but there are other, polar constituents of A. annua, which have similar effects. There is a potential of using our findings in codling moth control and production of codling moth-resistant apples.

Major histocompatibility complex diversity in the endangered Ethiopian wolf (Canis simensis)

The major histocompatibility complex (MHC) influences immune response to infection and vaccination. In most species, MHC genes are highly polymorphic, but few wild canid populations have been investigated. In Ethiopian wolves, we identified four DLA (dog leucocyte antigen)-DRB1, two DLA-DQA1 and five DQB1 alleles. Ethiopian wolves, the world's rarest canids with fewer than 500 animals worldwide, are further endangered and threatened by rabies. Major rabies outbreaks in the Bale Mountains of southern Ethiopia (where over half of the Ethiopian wolf population is located) have killed over 75% of wolves in the affected sub-populations. In 2004, following a rabies outbreak, 77 wolves were vaccinated, and 19 were subsequently recaptured to monitor the effectiveness of the intervention. Pre- and post-vaccination rabies antibody titres were available for 18 animals, and all of the animals sero-converted after vaccination. We compared the haplotype frequencies of this group of 18 with the post-vaccination antibody titre, and showed that one haplotype was associated with a lower response (uncorrected P < 0.03). In general, Ethiopian wolves probably have an adequate amount of MHC variation to ensure the survival of the species. However, we sampled only the largest Ethiopian wolf population in Bale, and did not take the smaller populations further north into consideration.

Genetic susceptibility to raised dermal scarring

Raised skin scars, such as keloid and hypertrophic scars mostly occur post-wounding in the human dermis. There is compelling evidence for a genetic component to these conditions, given the familial predisposition, varied incidence in different ethnic populations and the presence in twins. The aim of this study was to perform a systematic review of the literature regarding genetic susceptibility to raised dermal scarring. We identified relevant articles by a systematic search of relevant search engines. Key search terms included: keloid disease, hypertrophic scarring, fibrosis, linkage analysis, gene expression, human leucocyte antigen system (HLA), twins, families, case-control association study and congenital syndromes. Numerous candidate genes have been identified, along with potential linkage regions on different chromosomes. Recent data also suggest that carriers of specific major histocompatibility complex (MHC) alleles, in particular HLA-DRB1*15, HLA-DQA1*0104, DQB1*0501 and DQB1*0503, are at increased risk of developing keloid scarring. In addition, distinct immunophenotypical profiles can distinguish between keloid and hypertrophic scars. Keloid and hypertrophic scars are multifaceted aberrations of the healing process with as yet incompletely understood aetiologies. Current data suggest a genetic susceptibility with a strong immunogenic component to dermal fibrosis with MHC genes being implicated. It appears unlikely that a single gene is responsible for the development of raised dermal scars. A likely scenario may involve the interaction of several gene pathways in addition to environmental factors. The ability to assess accurately an individual's potential genetic susceptibility to raised scarring may lead to a more personalized approach to their management in the future.

Safety and efficacy of intravenous zoledronic acid in paediatric osteoporosis

AIM

To study the safety and efficacy of zoledronic acid treatment in children with osteoporotic bone disorders.

STUDY DESIGN

Observational study in 22 patients with osteogenesis imperfecta and related conditions who were treated at our institution with zoledronic acid. These patients had initial treatment with pamidronate. Lumbar spine z-scores, annual change in areal bone mineral density, bone mineral adjusted density, fracture number and linear growth before and after zoledronic acid treatment was commenced were compared.

RESULTS

Patients were treated for a mean of 3.4 years with zoledronic acid after a mean of 3.75 years of pamidronate therapy. There was no difference in areal bone mineral density accrual in the first year of zoledronic acid treatment compared to the preceding year of pamidronate treatment. Lumbar spine z-scores and bone mineral adjusted density continued to increase with zoledronic acid. Number of fractures during treatment was significantly reduced compared to baseline with either bisphosphonate, with no difference between treatments. Linear growth was not affected.

CONCLUSIONS

Zoledronic acid is at least as effective as pamidronate as treatment for paediatric osteoporosis, and has a similar safety profile.

Positive association of HLA-DRB1*15 with Dupuytren's disease in Caucasians

Dupuytren's disease (DD) is a permanent nodular condition affecting the palms and digits of the hands, leading to progressive shortening and contractures of the digits often resulting in diminished function and severe deformity. DD is thought to be one of the most common hereditary connective tissue disorders in Caucasians. To elucidate further the aetiology of DD, we compared the HLA-DRB1 phenotype frequencies of DD patients (n=67) against the HLA-DRB1 phenotype frequencies observed in a control population (n=537). HLA-DRB1*15 phenotype frequency was higher in DD positive Caucasoids (37.3%) when compared with control data (20.9%) (corrected P=0.029): we conclude that in Caucasoids of European origin, HLA-DRB1*15 is associated with risk of developing DD.

Plant polyphenols and multidrug resistance: Effects of dietary flavonoids on drug transporters in Caco-2 and MDCKII-MDR1 cell transport models

The hypothesis tested was that specific flavonoids such as epicatechin gallate, epigallocatechin gallate, genistein, genistin, naringenin, naringin, quercetin and xanthohumol will modulate cellular uptake and permeability (P(e)) of multidrug-resistant substrates, cyclosporin A (CSA) and digoxin, across Caco-2 and MDCKII-MDR1 cell transport models. (3)H-CSA/(3)H-digoxin transport and uptake experiments were performed with and without co-exposure of the flavonoids. Aglycone flavonoids reduced the P(e) of CSA to a greater extent than glycosylated flavonoids with 30 microM xanthohumol producing the greatest effect (7.2 x 10(-6) to 6.6 x 10(-7) and 17.9 x 10(-6) to 4.02 x 10(-6) cm s(-1) in Caco-2 and MDCKII-MDR1 cells, respectively); while no measurable effects were seen with digoxin. Xanthohumol significantly demonstrated (1) saturable efflux, (2) increased uptake of (3)H-digoxin and (3) decreased uptake of (3)H-CSA in the Caco-2 cells. The transport data suggests that xanthohumol effects transport of CSA in a manner that is distinct from the digoxin efflux pathway and suggests that intestinal transport of these MDR1 substrates is more complex than previously reported.

Bisphosphonate-associated osteonecrosis of the jaw: does it occur in children?

BACKGROUND

Bisphosphonate use in adult patients has been linked to osteonecrosis of the jaw (ONJ). This complication has not been systematically assessed in a paediatric population receiving bisphosphonates.

OBJECTIVE

To assess our cohort of paediatric patients treated with intravenous bisphosphonate for occurrence of ONJ.

DESIGN

Observational study at a tertiary children's hospital.

PATIENTS

A total of 42 paediatric patients with osteoporosis who received bisphosphonate infusions for a mean of 6.5 years (SD 2.7 years) were assessed clinically and radiographically for possible ONJ. Among 42, 37 patients had received disodium pamidronate 1 mg/kg/dose at a mean cumulative dose of 19.8 mg/kg and zoledronic acid (ZA) 0.05 mg/kg/dose at a mean cumulative dose of 0.49 mg/kg; four had received ZA and one received pamidronate alone. Invasive dental treatment during bisphosphonate treatment, a known risk factor for osteonecrosis, was specifically assessed.

RESULTS

In all patients assessed, including 11 who had invasive dental treatment, there were no cases of osteonecrosis.

CONCLUSION

ONJ has so far not been demonstrated in this patient group.

Major histocompatibility complex typing of dogs from Russia shows further dog leukocyte antigen diversity

Blood samples from 85 Russian dogs and wolves were collected as dried blood spots on paper and transported to the UK by mail. We obtained partial or complete three-locus canine major histocompatibility complex [dog leukocyte antigen (DLA)] class II haplotypes on 81 of these samples. Six new alleles were identified: three DLA-DRB1 and three DLA-DQB1. These alleles occurred in haplotypic combinations not previously seen in other European dogs. One haplotype appeared to lack a DQB1 allele. Two of the new haplotypes segregated through a family of dogs that was investigated.

Canine DLA diversity: 1. New alleles and haplotypes

The aim of this component was to establish the range of DLA diversity in as many dog breeds as possible. In particular, we wanted to collect breeds that had not previously been studied. Data were submitted of 937 dogs of over 80 different breeds, and these included 17 'new' breeds. Twenty-eight new alleles were identified including 21 DLA-DRB1, 2 DLA-DQA1 and 5 DLA-DQB1 alleles. These occurred in many new haplotype combinations. One haplotype was identified that appeared to lack DQB1. Two other haplotypes carry two DQB1 genes. It was clear that each dog breed has a restricted range of DLA alleles and haplotypes, and no breed had all 88 haplotypes identified in this study.

Magnetic resonance imaging of the gallbladder: spectrum of abnormalities

Various pathologies involving the gallbladder can manifest clinically, producing nonspecific clinical symptoms and making diagnosis difficult and challenging. Real-time sonography is the most widely used diagnostic study for the gallbladder and the primary screening examination of choice. With increasing use of magnetic resonance imaging (MRI) and MR cholangiopancreatography (MRCP), gallbladder pathology is frequently seen. Understanding the basic patterns of various disease manifestations and appearance on MRI is the key to making an accurate diagnosis. Given its inherent tissue contrast and contrast sensitivity, MRI in conjunction with MRCP can be a very valuable test in evaluating gallbladder pathology. Gallbladder pathology can be classified into congenital (such as absence), inflammatory (acute, hemorrhagic, and chronic cholecystitis), traumatic, benign (polyps) and malignant tumors (gallbladder carcinoma and lymphoma), and other disease processes can be seen in cholelithiasis, cholesterosis, thickened gallbladder wall, and Mirrizzi syndrome.

Mycobacterial infections in striped bass from Delaware Bay

Eighty striped bass Morone saxatilis were obtained from Delaware Bay using commercial gill nets set adjacent to Woodland Beach (n = 70) and Bowers Beach (n = 10) in December 2003. Fish were examined for gross lesions. Total lengths (TLs) and eviscerated weights were determined to calculate condition factors (K). Portions of spleens were aseptically harvested for bacterial culture, and portions of spleens, kidneys (anterior and posterior), livers, and gonads were obtained for histological examination. The size distribution of the striped bass was relatively homogeneous; the mean TL was about 600 mm for all samples. Mean K exceeded 0.95 in all samples and was not significantly different (P > 0.05) among samples. Significant differences in mycobacterial infection prevalence (P < or = 0.05) were observed among samples; samples obtained at Woodland Beach (WB) on December 10 (53.8%, n = 13) and December 17 (7.1%, n = 42) exhibited the most striking differences in prevalence. Mycobacterial infection intensity ranged from 1 X 10(2) to 1 X 10(7) colony-forming units per gram of spleen. Acanthocephalan infection prevalence and intensity, non-acid-fast bacterial infection prevalence, and fish sex ratio were also significantly different among the samples (P < or = 0.05). Similar to the mycobacterial infections, differences in sex ratio, acanthocephalan infection, and non-acid-fast bacterial infection were observed between the WB samples taken on December 10 and 17. However, no significant associations (P > 0.05) were observed between sex ratio or these infections and mycobacterial infection. The differences in bacterial and parasite infection prevalence and intensity and fish sex ratio in some samples indicate that these fish had a different history and that the epizootiology of mycobacterial infection in striped bass from Delaware Bay may be relatively complex.

Canine DLA diversity: 2. Family studies

The canine Major Histocompatibility Complex is referred to as DLA (for dog leukocyte antigen). There are no published studies on DLA segregation in the dog, so this part of the DLA workshop aimed to collect DNA from multigeneration families of different breeds of dogs. Twenty-two families of dogs were submitted to the workshop, comprising 313 individuals, of which 247 had one or both parents available.

Canine DLA diversity: 3. Disease studies

There are many millions of dogs worldwide, and these dogs have many different functions. The most obvious use is providing companionship, but there are also many working dogs, including guide dogs for the blind, hearing dogs, guard dogs and farm dogs, to mention a few. The health and welfare of these dogs is of great concern to dog owners, dog breeders and to those who use dogs in their work. Dogs spontaneously develop many diseases that are very similar to their human counterparts. Dogs may, therefore, provide exceptional animal models for such diseases. Identifying genetic markers in the dog may be easier than in humans, and may then provide useful information about genes that can be transferred to humans. This study looked for associations between DLA and two autoimmune diseases of the dog, diabetes and hypothyroidism. DLA associations were found for both of these diseases.

TNF-alpha SNP haplotype frequencies in equidae

Tumour necrosis factor alpha (TNF-alpha) is a pro-inflammatory cytokine that plays a crucial role in the regulation of inflammatory and immune responses. In all vertebrate species the genes encoding TNF-alpha are located within the major histocompatability complex. In the horse TNF-alpha has been ascribed a role in a variety of important disease processes. Previously two single nucleotide polymorphisms (SNPs) have been reported within the 5' un-translated region of the equine TNF-alpha gene. We have examined the equine TNF-alpha promoter region further for additional SNPs by analysing DNA from 131 horses (Equus caballus), 19 donkeys (E. asinus), 2 Grant's zebras (E. burchellii boehmi) and one onager (E. hemionus). Two further SNPs were identified at nucleotide positions 24 (T/G) and 452 (T/C) relative to the first nucleotide of the 522 bp polymerase chain reaction product. A sequence variant at position 51 was observed between equidae. SNaPSHOT genotyping assays for these and the two previously reported SNPs were performed on 457 horses comprising seven different breeds and 23 donkeys to determine the gene frequencies. SNP frequencies varied considerably between different horse breeds and also between the equine species. In total, nine different TNF-alpha promoter SNP haplotypes and their frequencies were established amongst the various equidae examined, with some haplotypes being found only in horses and others only in donkeys or zebras. The haplotype frequencies observed varied greatly between different horse breeds. Such haplotypes may relate to levels of TNF-alpha production and disease susceptibility and further investigation is required to identify associations between particular haplotypes and altered risk of disease.

Proposals for prevention and management of steroid-induced osteoporosis in children and adolescents

The adverse effects of glucocorticoids on bone health are well recognized. In adults, evidence-based guidelines exist to base management of patients with glucocorticoid-induced osteoporosis. Osteoporosis is also recognized in children and adolescents with chronic disease requiring steroid treatment. Additional complexities in the assessment and management of growing children mean that evidence-based guidelines for this complex patient group have not been produced. Factors, which need to be taken into account, include defining osteoporosis in childhood and addressing the effects of chronic disease and glucocorticoid treatment on a number of parameters including the skeleton, growth, puberty, nutrition and vitamin D status. In the absence of randomized controlled trials to guide clinical practice, we provide proposals for the prevention and management of steroid-induced osteoporosis, drawing on the available evidence and our clinical experience of managing children and adolescents with steroid-induced osteoporosis.

Attempted randomized controlled trial of pamidronate versus calcium and calcitriol supplements for management of steroid-induced osteoporosis in children and adolescents

OBJECTIVES

To describe an attempted interventional trial for glucocorticoid-induced osteoporosis in children and adolescents and to discuss the reasons for trial failure to inform future interventional studies in this important group of patients.

METHODS

Prospective randomized controlled trial comparing the effect of bisphosphonate therapy with calcium and vitamin D supplementation on bone mineral accrual is described. For non-trial patients, retrospective analysis of the effect of calcium and vitamin D supplementation combined with bisphosphonate treatment on bone mineral accrual.

RESULTS

Only 12 patients were enrolled in the trial over 4 years. Bisphosphonate recipients (n = 5) had a mean annual percentage increase in lumbar spine bone mineral density of 8.76 +/- 5.2% compared to 6.6 +/- 4.0% in the calcium/vitamin-treated group (difference not significant). Mean annual change in lumbar spine areal bone mineral density in non-trial patients (n = 11) was 3.72 +/- 2.5%.

CONCLUSION

Conducting a randomized controlled trial in this group of corticosteroid users is difficult, given the unpredictable nature of the underlying disease and intermittent need for steroid treatment. The trial failed through inadequate recruitment combined with discontinued interventions.

Polymorphisms of the equine major histocompatibility complex class II DRA locus

The full extent of the polymorphism of ELA-DRA in Equidae is not yet known. Given the apparent differences in DRA polymorphisms between Equidae and other species, the aims of this study were to more fully characterize ELA-DRA, determine the extent of gene polymorphism and establish the allele-frequency distribution. An allele reference panel for the second exon of ELA-DRA was established by sequence-based typing of 69 equine DNA samples consisting of various breeds of domestic horse (Equus caballus), together with donkeys (Equus asinus), Grant's zebras (Equus boehmi) and one onager (Equus hemionus). Five of the six previously reported alleles detected using single-strand conformation polymorphism were found: ELA-DRA*0101, ELA-DRA*0201, ELA-DRA*0301, ELA-DRA*0501 (Albright-Fraser DG et al. Polymorphism of DRA among equids. Immunogenetics 1996: 43: 315-7) and ELA-DRA*0601 (GenBank accession number AF5419361). In addition to the previously reported alleles, five novel ELA-DRA alleles were detected within the ELA-DRA allele reference panel. One of these was identified in E. caballus (ELA-DRA*JBH11), one in E. boehmi and E. hemionus (ELA-DRA*JBZ185) and three in E. asinus (ELA-DRA*JBD3, ELA-DRA*JBD17 and ELA-DRA*JBH45). A total of 565 equine DNA samples were screened using reference-strand-mediated conformation analysis, a double-stranded conformation-based mutation detection system that can be used to type existing ELA-DRA alleles and identify new variants. Based on our findings, at least 11 ELA-DRA alleles are now known to exist, and this level of polymorphism at the DRA locus appears to be unique to the genus Equus. Both the previously reported alleles and the new alleles displayed a species-specific distribution.

Graves' disease in DiGeorge syndrome: patient report with a review of endocrine autoimmunity associated with 22q11.2 deletion

DiGeorge syndrome, which falls within a wider phenotypic spectrum associated with deletions of 22q11.2, is associated with a number of endocrine disorders. These include hypoparathyroidism, hypothyroidism and growth hormone deficiency. We report an unusual case of autoimmune hyperthyroidism (Graves' disease) presenting in a 3 year-old male with DiGeorge syndrome. The development of endocrine specific autoimmune disease in a syndrome associated with immune deficiency and the spectrum of endocrine autoimmunity associated with deletions of 22q11.2 are described. Paediatricians and patients with 22q11.2 deletions should be particularly aware of the risks of developing disorders of thyroid function.

24-hour ambulatory blood pressure profile in patients with congenital adrenal hyperplasia--a preliminary report

BACKGROUND

Blood pressure (BP) is maintained within normal limits by the interplay of various mechanisms including the action of cortisol and aldosterone. However, these hormones when exogenously administered are not under the regulatory feedback mechanisms that maintain BP homeostasis. Treatment of congenital adrenal hyperplasia (CAH) requires glucocorticoid replacement (with or without additional mineralocorticoid) at supra-physiological doses to normalize the pituitary adrenocortical axis.

HYPOTHESIS

Long-term use of glucocorticoids at supra-physiological doses may result in high BP.

OBJECTIVE

To document any changes in BP in patients with CAH following long-term conventional glucocorticoid replacement therapy.

PATIENTS AND METHODS

24-hour ambulatory BP (AmBP) monitoring was performed in 11 patients with CAH, all of whom were on glucocorticoid replacement at supra-physiological doses. In addition, a single random BP measurement was taken in each patient at enrolment. Mean systolic and diastolic pressure during awake and sleep periods, systolic and diastolic BP loads, and systolic and diastolic BP dips were calculated from the 24-hour AmBP profile of each patient, which was correlated with demographic and treatment details. AmBP readings were compared to Task Force references for casual BP and also to recently available AmBP specific reference values.

RESULTS

None of the patients had significant BP loads at the 95th percentile (hypertensive BP range) using references for casual BP readings. However, in the subgroup of patients who had significant BP load at the 90' percentile (high normal BP range), higher mean systolic and diastolic pressures were noticed during the awake period. Seven patients did not have a systolic dip with or without a diastolic dip. There was no significant correlation between various BP parameters and demographic or treatment details in our sample. However, one patient had daytime systolic hypertension and six had nocturnal hypertension using AmBP specific reference values.

CONCLUSIONS

In this preliminary study, longterm glucocorticoid replacement therapy at supra-physiological doses does not seem to be associated with hypertension in young people with CAH when using casual BP references. However, higher mean BP was noticed in the subgroup of patients with significant systolic or diastolic BP load at high normal BP range, and evidence of daytime and nocturnal hypertension was uncovered using AmBP specific reference values. Further large trials using appropriate BP references are necessary to clarify the significance of these findings.

Achieving early surgery for undescended testes: quality improvement through a multifaceted approach to guideline implementation

BACKGROUND

Surgery for undescended testes is recommended before the age of 2 years. However, boys are still undergoing surgery for undescended testes at a much later age than recommended.

METHODS

An initial audit reviewed all orchidopexies performed at Northampton General Hospital between 1992 and 1994. This demonstrated that only 19% of boys had surgery by the age of 2 years, and the key reason for late surgery was late referral. Guidelines for referral of undescended testes were established in which referral to a surgeon was advised following the 8-month child health surveillance check if undescended testis was suspected. This would enable surgery before the age of 2 years. Audit results were disseminated and we implemented a package of measures based on evidence based change management techniques. These included written advice to general practitioners (GPs), a parent information leaflet and an amended personal child health record advising timing of referral. A reminder to the GP to refer following the 8-month check was generated using computer recall from the Child Health System records. Guideline implementation was monitored by annual audit and feedback.

RESULTS

The baseline audit for the years 1992-94 found a median age at surgery of 4 years. Implementation of the new policies in 1998 resulted in a reduction in median age at surgery to 2.0 years in the 12 months ending September 2001.

CONCLUSIONS

While concern about the age at orchidopexy has been highlighted in many previous studies, this is the first to show that improvement in the age at orchidopexy can be achieved. Implementing locally agreed guidelines with written information to GPs and parents combined with computerized recall from Child Health System records achieved the target within 3 years. Similar systems could be implemented nationally at minimal cost.

Chloride/phosphate ratio in primary hyperparathyroidism

The chloride/phosphate (Cl:PO4) ratio is known to help distinguish between the hypercalcemia of primary hyperparathyroidism (HPT) and hypercalcemia from other causes. The Cl:PO4 ratio of 106 patients with surgically proven primary HPT was compared with that of 126 normocalcemic healthy outpatients to examine its usefulness as a confirmatory test for primary HPT. The Cl:PO4 ratio was significantly higher in patients with HPT (42.5 +/- 7.0) compared with healthy controls (28.7 +/- 4.6). Patients with HPT and mild renal insufficiency (serum creatinine, 1.5-2.4 mg/dL) also showed a significant increase in the Cl:PO4 ratio (37.3 +/- 6.6) as did those with HPT with borderline elevations in serum calcium (calcium < 11; Cl:PO4, 40.3 +/- 5.6). A Cl:PO4 ratio > or = 33 is a reliable diagnostic test for primary HPT when compared with a normal population. The Cl:PO4 ratio is also of value in the evaluation of the patient with suspected HPT and borderline calcium elevation and those with mild renal impairment. These data suggest that an inexpensive Cl:PO4 ratio might replace serum parathormone assay as a confirmatory test in the evaluation of suspected primary HPT, especially for those patients in whom a localizing study (sestamibi scan) is obtained before neck exploration.

Resolution of complex feline leukocyte antigen DRB loci by reference strand-mediated conformational analysis (RSCA)

The DRB genes of the domestic cat are highly polymorphic. Studies based on clonal sequence analysis have suggested the existence of two distinct loci within individual animals and good evidence for 24 distinct FLA-DRB alleles. This variability, the complexity of clonal sequence analysis and its susceptibility to PCR-induced artefacts has represented a bottleneck to further progress. In this study we have applied reference strand-mediated conformational analysis (RSCA) to FLA-DRB. This protocol has been shown to be highly reproducible. Using five reference strands including two derived from non-domestic felines, we could distinguish 23 FLA-DRB alleles. We used RSCA to explore genetic polymorphism of FLA-DRB in 71 cats including 31 for which clonal sequence analysis was also available. On average, RSCA identified 0.9 more alleles within cats than clonal sequence analysis. Reference strand-mediated conformational analysis was also able to identify animals containing new alleles that could be targeted for sequence analysis. Analysis of allele patterns showed clear evidence for different allele distributions between breeds of cats, and suggested the Burmese breed may have highly restricted FLA-DRB polymorphism. Results from two families provided clear evidence for variation in the number of DRB genes on different haplotypes, with some haplotypes carrying two genes and some containing three. This study highlights the utility of RSCA for the resolution of complex amplicons containing up to six distinct alleles. A simple, rapid method for characterizing FLA-DRB makes possible studies on vaccine response and susceptibility/resistance to viral infections, which are a significant clinical problem in cats.

Suppression of TSH in congenital hypothyroidism is significantly related to serum levels and dosage of thyroxine

AIM

To assess thyrotropin (thyroid-stimulating hormone; TSH) suppression and serum thyroxine (T(4)) concentrations in infants with congenital hypothyroidism in relation to T(4) dose and pretreatment parameters.

METHOD

A retrospective study of all cases treated in a single centre since neonatal screening began was performed.

RESULTS

In 54 infants treated with a mean daily T(4) dose of 9.8 microg/kg, the TSH concentration was suppressed (<6 mU/l) in 65% of the cases by 6 months with the serum T(4) level at the upper end of the infant reference range. Infants who suppressed their TSH later did not differ in pretreatment serum TSH or T(4) concentration. T(4) dose and serum T(4) level were lower in infants whose TSH was not suppressed.

CONCLUSIONS

TSH suppression in congenital hypothyroidism is significantly related to serum levels and dosage of T(4). We suggest that a delay in TSH suppression is mainly due to undertreatment.

Chilling affects allatal cell proliferation via antennae and protocerebral neurons in the cockroach Diploptera punctata

The corpora allata (CA) cells in a mated female of the cockroach Diploptera punctata undergo numerous mitotic divisions before an increase in juvenile hormone synthesis. A previous study demonstrated that this mitotic wave could be suppressed by exposure of the mated female to melting ice. Herein, we report that chilling suppresses CA mitosis via antennal perception. Cell proliferation-suppressing stimuli from chilling were acquired in proportion to the length of time of exposure to the low temperature and the physical length of the antennae exposed to chilling. Sixty basal antennal annuli should remain exposed to chilling for at least 1.5 h in order to suppress mitotic divisions in CA. Mitotic divisions in corpus allatum are suppressed by stimuli from contralateral antenna, predominantly via pars intercerebralis neurons. Selective disconnection of pars intercerebralis neurons from CA, prior to chilling, restored the mitotic wave in CA. Cellular divisions did not occur in CA of chilled females if either pars lateralis neurons were severed or left intact.

Evaluation of metallothionein and p53 expression as potential prognostic markers for laryngeal squamous cell carcinoma

The aim of the study was to determine the contribution of metallothionein (MT) and p53 expression in predicting laryngeal squamous cell carcinoma (SCC) recurrence. This was a retrospective study in which MT and p53 immunopositive staining in 32 laryngeal SCC paraffin-embedded sections, were correlated with clinical recurrence. Recurrence was observed in 8 cases with MT expression (42.1%) and 1 case with no expression (7.7%). Moderate and strong MT expression was associated with 14.3% and 58.3% recurrence, respectively. Recurrence was similar for both p53-negative (21.1%) and p53-positive (27.3%) groups. One third of the patients expressing both p53 and MT simultaneously had recurrence. Thus, the combined expression of p53 and MT did not improve the predictive value for recurrence compared to MT alone. MT over-expression may be an independent risk factor for laryngeal SCC recurrence.

Splenic imaging with ultrasmall superparamagnetic iron oxide ferumoxtran-10 (AMI-7227): preliminary observations

PURPOSE

Ferumoxtran-10 (ultrasmall superparamagnetic iron oxide; Combidex, AMI-7227) is a long-circulating MR contrast agent with reticuloendothelial uptake known to enhance tissue T1 and T2 relaxation rates. The purpose of this study was to assess the effect of ferumoxtran-10-enhanced MRI in evaluating focal splenic lesions.

METHOD

Eighteen patients underwent MR evaluation of the spleen. Two of these patients with exophytic normal splenic tissue (splenules) and 13 of these patients with 24 focal splenic lesions (7 cysts, 2 hemangiomas, 7 metastases, 1 infarct, 7 lymphoma) were assessed by T1-weighted gradient echo and T2-weighted fast SE MRI following intravenous administration of ferumoxtran-10 (1.1 mg of Fe/kg). Qualitative analysis involving improved lesion detection and/or characterization, additional information from postcontrast images affecting staging, and patient management was performed. Quantitative measurements of lesion-to-spleen contrast-to-noise ratio were also performed.

RESULTS

Additional information was provided by ferumoxtran-10-enhanced images in 15 of 18 patients. In 8 of 15 (53%) patients, improved lesion detection (i.e., number of lesions) was obtained on contrast-enhanced images. Improved lesion visualization (i.e., conspicuity) was noted in 11 of 15 (73%) of patients. In 10 of 15 (67%) patients, postcontrast imaging provided additional information leading to lesion characterization. Staging of disease and patient management were affected in 5 of 15 (33%) and 6 of 15 (40%) patients, respectively.

CONCLUSION

Ferumoxtran-10 is a promising contrast agent for the evaluation of focal splenic lesions.

Principles and applications of echo-planar imaging: a review for the general radiologist

Echo-planar imaging is a very fast magnetic resonance (MR) imaging technique capable of acquiring an entire MR image in only a fraction of a second. In single-shot echo-planar imaging, all the spatial-encoding data of an image can be obtained after a single radio-frequency excitation. Multishot echo-planar imaging results in high-quality images comparable to conventional MR images. However, echo-planar imaging offers major advantages over conventional MR imaging, including reduced imaging time, decreased motion artifact, and the ability to image rapid physiologic processes of the human body. The use of echo-planar imaging has already resulted in significant advances in clinical diagnosis and scientific investigation, such as in evaluation of stroke and functional imaging of the human brain, respectively. The clinical indications for echo-planar imaging are expanding rapidly, and it can now be applied to many parts of the body, including the brain, abdomen, and heart. Today, with the availability of echo-planar imaging-capable MR imagers at many sites, the general radiologist can benefit from echo-planar imaging and its clinical applications.

Identification of differentially expressed genes in human papillomavirus type-16 infected oral cancer cells

OBJECTIVE

The goal of this study was to determine the genes required for head and neck cancer development.

STUDY DESIGN AND SETTING

Differential mRNA display analysis was performed using human papillomavirus Type-16 infected immortalized human oral keratinocytes (HOK-16B) and its benzo(a)pyrene-exposed tumorigenic derivative (HOK-16B-BaP-T).

RESULTS

Twenty-one differentially expressed cDNA clones were identified between the 2 cell lines. Clone 4 with no known homology showed lower expression in tumorigenic cells compared with either normal or immortalized oral keratinocytes. Clone 6 expression was elevated in several head and neck cancer cells, in addition to Burkitt's lymphoma Raji harboring latent Epstein-Barr virus.

CONCLUSION

These findings suggested that clone 6 may be involved in the oncogenic transformation whereas clone 4 may potentially function as a tumor suppressor gene.

SIGNIFICANCE

Differential mRNA analysis using the in vitro oral carcinogenesis model may help to identify important genetic markers for the early detection and progression of head and neck cancer.