Intrinsic polarity inversion in III-nitride waveguides for efficient nonlinear interactions

III-nitrides provide a versatile platform for nonlinear photonics. In this work, we explore a new promising configuration - composite waveguides containing GaN and AlN layers with inverted polarity, i.e., having opposite signs of the χ(2) nonlinear coefficient. This configuration allows us to address the limiting problem of the mode overlap for nonlinear interactions. Our modelling predicts a significant improvement in the conversion efficiency. We confirm our theoretical prediction with the experimental demonstration of second harmonic generation with an efficiency of 4%W-1cm-2 using a simple ridge waveguide. This efficiency is an order of magnitude higher compared to the previously reported results for III-nitride waveguides. Further improvement, reaching a theoretical efficiency of 30%W-1cm-2, can be achieved by reducing propagation losses.

Low-loss GaN-on-insulator platform for integrated photonics

III-Nitride semiconductors are promising materials for on-chip integrated photonics. They provide a wide transparency window from the ultra-violet to the infrared that can be exploited for second-order nonlinear conversions. Here we demonstrate a photonics platform based on epitaxial GaN-on-insulator on silicon. The transfer of the epi-material on SiO₂ is achieved through wafer bonding. We show that quality factors up to 230 000 can be achieved with this platform at telecommunication wavelengths. Resonant second harmonic generation is demonstrated with a continuous wave conversion efficiency of 0.24%/W.

Feasibility and Safety of Tethered Capsule Endomicroscopy in Patients With Barrett's Esophagus in a Multi-Center Study

BACKGROUND & AIMS

Tethered capsule endomicroscopy (TCE) involves swallowing a small tethered pill that implements optical coherence tomography (OCT) imaging, procuring high resolution images of the whole esophagus. Here, we demonstrate and evaluate the feasibility and safety of TCE and a portable OCT imaging system in patients with Barrett's esophagus (BE) in a multi-center (5-site) clinical study.

METHODS

Untreated patients with BE as per endoscopic biopsy diagnosis were eligible to participate in the study. TCE procedures were performed in unsedated patients by either doctors or nurses. After the capsule was swallowed, the device continuously obtained 10-μm-resolution cross-sectional images as it traversed the esophagus. Following imaging, the device was withdrawn through mouth, and disinfected for subsequent reuse. BE lengths were compared to endoscopy findings when available. OCT-TCE images were compared to volumetric laser endomicroscopy (VLE) images from a patient who had undergone VLE on the same day as TCE.

RESULTS

147 patients with BE were enrolled across all sites. 116 swallowed the capsule (79%), 95/114 (83.3%) men and 21/33 (63.6%) women (P = .01). High-quality OCT images were obtained in 104/111 swallowers (93.7%) who completed the procedure. The average imaging duration was 5.55 ± 1.92 minutes. The mean length of esophagus imaged per patient was 21.69 ± 5.90 cm. A blinded comparison of maximum extent of BE measured by OCT-TCE and EGD showed a strong correlation (r = 0.77-0.79). OCT-TCE images were of similar quality to those obtained by OCT-VLE.

CONCLUSIONS

The capabilities of TCE to be used across multiple sites, be administered to unsedated patients by either physicians or nurses who are not expert in OCT-TCE, and to rapidly and safely evaluate the microscopic structure of the esophagus make it an emerging tool for screening and surveillance of BE patients. Clinical trial registry website and trial number: NCT02994693 and NCT03459339.

1629 The Risk of Malignancy in Cytologically Indeterminate Thyroid Nodules

Introduction

Fine needle aspiration (FNA) is the gold standard for the diagnostic assessment of thyroid nodules, with cytology stratified using the Thy classification (Thy 1-5). The management of cases where cytology is indeterminate (Thy-3) is challenging and subject to controversy. The current British Thyroid Association guidelines subclassify Thy-3 lesions into Thy-3a (atypia) and Thy-3f (follicular). Repeat FNA is generally recommended for Thy-3a specimens, whilst Thy-3f lesions should proceed to diagnostic hemithyroidectomy. The aim of this study was to determine the risk of malignancy in Thy-3a and Thy-3f lesions.

Method

This was a retrospective study of all patients who underwent FNA of a thyroid nodule from 01/01/2018 – 31/12/19. Those with Thy-3 cytology were identified and results correlated with final surgical histology.

Results

In total, there were 179 patients with Thy-3 cytology: 37 Thy-3a and 142 Thy-3f. The rate of malignancy was 21.6% (n = 8) for Thy-3a lesions and 20.4% (n = 29) for Thy-3f. When excluding microcarcinoma, the rates fell to 20.4% (n = 7) and 12.7% (n = 18) respectively. There was no statistically significant difference in malignant conversion between the two groups (p = 0.20).

Conclusions

This study does not demonstrate any statistically significant difference in the risk of malignancy between the Thy-3a and Thy-3f groups, suggesting that this subclassification does not add any additional utility to clinical decision making. Consideration should be given to the use of local malignant conversion rates to guide further management and pre-operative patient counselling in the Thy3 group.

Immunogenicity and safety of two monovalent rotavirus vaccines, ROTAVAC® and ROTAVAC 5D® in Zambian infants

BACKGROUND AND AIMS

ROTAVAC® (frozen formulation stored at -20 °C) and ROTAVAC 5D® (liquid formulation stable at 2-8 °C) are rotavirus vaccines derived from the 116E human neonatal rotavirus strain, developed and licensed in India. This study evaluated and compared the safety and immunogenicity of these vaccines in an infant population in Zambia.

METHODS

We conducted a phase 2b, open-label, randomized, controlled trial wherein 450 infants 6 to 8 weeks of age were randomized equally to receive three doses of ROTAVAC or ROTAVAC 5D, or two doses of ROTARIX®. Study vaccines were administered concomitantly with routine immunizations. Blood samples were collected pre-vaccination and 28 days after the last dose. Serum anti-rotavirus IgA antibodies were measured by ELISA, with WC3 and 89-12 rotavirus strains as viral lysates in the assays. The primary analysis was to assess non-inferiority of ROTAVAC 5D to ROTAVAC in terms of the geometric mean concentration (GMC) of serum IgA (WC3) antibodies. Seroresponse and seropositivity were also determined. Safety was evaluated as occurrence of immediate, solicited, unsolicited, and serious adverse events after each dose.

RESULTS

The study evaluated 388 infants in the per-protocol population. All three vaccines were well tolerated and immunogenic. The post-vaccination GMCs were 14.0 U/mL (95% CI: 10.4, 18.8) and 18.1 U/mL (95% CI: 13.7, 24.0) for the ROTAVAC and ROTAVAC 5D groups, respectively, yielding a ratio of 1.3 (95% CI: 0.9, 1.9), thus meeting the pre-set non-inferiority criteria. Solicited and unsolicited adverse events were similar across all study arms. No death or intussusception case was reported during study period.

CONCLUSIONS

Among Zambian infants, both ROTAVAC and ROTAVAC 5D were well tolerated and the immunogenicity of ROTAVAC 5D was non-inferior to that of ROTAVAC. These results are consistent with those observed in licensure trials in India and support use of these vaccines across wider geographical areas.

First impression of teeth design on others: A facial and personality analysis in the Central Indian population

Background

Facial features and personality types vary with different geographical boundaries, culture, and ethnicity. The impression created by teeth design differs with the face and personality of males and females.

Aims

This study evaluated the dominant facial and personality types and their correlation among males and females in Central Indian population.

Subjects and Methods

The full-face photographs of 120 people, with a broad smile and visible dentition, were calibrated to generate a facial map with digital software. The participants filled a personality questionnaire. Facial form and personality type were classified as a combination of strong, dynamic, delicate, and calm. Descriptive and inferential statistics using Chi-square and Kappa tests.

Results

The dominant facial form was calm (66.67%, 71.67%) with the second dominant facial form being dynamic (50%, 51.67%) both for males and females respectively. While the dominant personality type was dynamic (50%), the second dominant personality type was calm (35%, 30%) for both males and females. Kappa analysis showed moderate agreement between the dominant facial and personality types (P = 0.41 in males, P = 0.10 in females). The software used was SPSS 22.0 version and P < 0.05 is considered as the level of significance.

Conclusions

A varying number of combinations are essential in characterizing the face. The personality type has a predominance of one type over other. The interpretation of these combinations in dentistry can help to select appropriate tooth forms and design a harmonious smile.

Maternal influenza and birth outcomes: systematic review of comparative studies

BACKGROUND

Although pregnant women are considered at high risk for severe influenza disease, comparative studies of maternal influenza and birth outcomes have not been comprehensively summarised.

OBJECTIVE

To review comparative studies evaluating maternal influenza disease and birth outcomes.

SEARCH STRATEGY

We searched bibliographic databases from inception to December 2014.

SELECTION CRITERIA

Studies of preterm birth, small-for-gestational-age (SGA) birth or fetal death, comparing women with and without clinical influenza illness or laboratory-confirmed influenza infection during pregnancy.

DATA COLLECTION AND ANALYSIS

Two reviewers independently abstracted data and assessed study quality.

MAIN RESULTS

Heterogeneity across 16 studies reporting preterm birth precluded meta-analysis. In a subgroup of the highest-quality studies, two reported significantly increased preterm birth (risk ratios (RR) from 2.4 to 4.0) following severe 2009 pandemic H1N1 (pH1N1) influenza illness, whereas those assessing mild-to-moderate pH1N1 or seasonal influenza found no association. Five studies of SGA birth showed no discernible patterns with respect to influenza disease severity (pooled odds ratio 1.24; 95% CI 0.96-1.59). Two fetal death studies were of sufficient quality and size to permit meaningful interpretation. Both reported an increased risk of fetal death following maternal pH1N1 disease (RR 1.9 for mild-to-moderate disease and 4.2 for severe disease).

CONCLUSIONS

Comparative studies of preterm birth, SGA birth and fetal death following maternal influenza disease are limited in number and quality. An association between severe pH1N1 disease and preterm birth and fetal death was reported by several studies; however, these limited data do not permit firm conclusions on the magnitude of any association.

TWEETABLE ABSTRACT

Comparative studies are limited in quality but suggest severe pandemic H1N1 influenza increases preterm birth.

Clinicopathological Spectrum Of Gall Bladder Cancer In Kashmir - An Institutional Study

Gallbladder cancer is a highly aggressive malignancy that usually presents at an advanced incurable stage. It is the fifth most common gastro-intestinal tumor and leads to approximately 2800 deaths in United States annually. This was a retrospective study carried out in the Department of Pathology, Sher-i-Kashmir Institute of Medical Sciences, a 650-bed super speciality hospital in Kashmir valley. We reviewed the histopathological records of all the patients who were diagnosed as carcinoma gallbladder from Dec 2009-Dec 2013. Gross findings and histopathological findings were noted from the departmental archival material and clinical records of the patients including the clinical presentation, laboratory investigations, radiological investigations, pre-operative diagnosis and intra-operative findings, were retrieved from the hospital records. We analyzed 57 cases of carcinoma gallbladder for their clinicopathological features It included 19 males and 37 females. In our study, adenocarcinomas accounted for 87.5% of total carcinomas. Incidentally, all but one patient where gall stones were found, adenocarcinomas were seen. We have 4 patients of squamous cell carcinoma. In our series we have a single case of small cell carcinoma which was positive for neuroendocrine markers. In our study, gall stones were seen only in 8 cases (14%) of the total cases.

Consenting for risk in common ENT operations: an evidence-based approach

Pre-operative consent discussion and documentation is an essential process that should follow relevant guidance, and include all serious or frequently occurring risks. We assessed the appropriateness of consent for grommet insertion, tonsillectomy, septoplasty, and hemithyroidectomy, by comparing the risks listed in current consenting practice to published complication data for the relevant operation. 120 consent forms and associated clinic letters were analysed. A literature search identified published complication data for comparison. There was great variation in consent practice for each operation type, and poor correlation with published risk incidence. Only 'bleeding' post-tonsillectomy and 'recurrent laryngeal nerve injury' post hemithyroidectomy were listed in 100 % of relevant cases. Common and serious complications were frequently omitted from forms. The number and type of risks consented for a procedure significantly differed between consultant and non-consultant staff. The potential requirement for blood transfusion was discussed in only 20 % of tonsillectomy cases. Currently, the pre-operative consent for commonly performed ENT operations does not reflect operative risks. Consenting for surgical complications should be evidence based using published or personal data. A change in the consent process is required to protect patient autonomy and meet both legal and professional body requirements.

The Impact of the European Working Time Regulations and Modernising Medical Careers on Out-of-hours ENT Cover

The implementation of the European Working Time Regulations (EWTR), coupled with the ongoing impact of Modernising Medical Careers (MMC), has necessitated a significant redevelopment of out-of-hours cover for surgical specialties in the UK. A review of the literature related to the provision of out-of-hours ENT cover gives an insight into the impact of these changes on a comparatively small surgical specialty. A 2008 survey revealed that three-quarters of junior doctors providing ENT out-of-hours care were crosscovering specialties other than ENT – a figure up from just over half of junior doctors in 2005, prior to stricter EWTR rules. Of all 'first-on-call' doctors for ENT, only 19–32% have prior ENT experience. Consequently, ENT services are provided frequently by inexperienced, non-enT doctors covering multiple other specialties, often as part of a 'hospital-at-night' team.

Expression of ets family genes in hematopoietic-cells

We have examined the expression of the ets family of transcription factors in different types of hematopoietic cells. Our results demonstrate that several members of the ets gene family are expressed differentially in hematopoietic cells. During phorbol ester induced differentiation of HL60 cells, ETS2, PEA3, as well as GABPalpha and GABPbeta mRNAs are coordinately induced. During the activation of T-cells, ETS2 proteins are induced; however, the expression of the ETS1 and ERGB gene products are reduced. These results demonstrate that the regulation of ets family of genes is complex and depends on cell type. This observation leads to the conclusion that the regulation of ets target genes, will be dependent, in part, upon the type of ets genes expressed in each particular cell type.

Pleiotropic functions of ETS-1 (Review)

ETS-1 is a cellular homologue of the viral ets oncogene of the E26 virus and functions as a sequence specific transcription factor. It plays an important role in cell proliferation, differentiation, lymphoid cell development, transformation, angiogenesis and apoptosis. ETS-1 may control the expression of critical genes involved in these processes by binding to ets binding sites present in their transcriptional regulatory regions. Recent progress in understanding the multiple functions of ETS-1 is summarized in this review.

Self-medication patterns among medical students in South India

BACKGROUND

Self-medication results in wastage of resources, increases resistance of pathogens and generally causes serious health hazards such as adverse drug reactions, prolonged suffering and drug dependence. This study was undertaken to determine the reasons for self-medication and the pattern of self-medication among medical students.

METHOD

This cross-sectional descriptive study was conducted at the K.S. Hegde Medical Academy, Mangalore. The participants were medical students from first to final year. Medical students were selected through convenience sampling. The data was collected using a pre-tested semi-structured questionnaire. The data was analysed using SPSS version 16 and the results expressed as proportions.

RESULTS

A total of 200 students, 121 (60.5%) female and 79 (39.5%) male, were included in the study. Of the medical students surveyed, self-medication was reported among 92%. The respondents who used self-medication found it to be time- saving in providing relief from minor ailments. The most common ailments for which self-medication were used were: the common cold (69%), fever (63%) and headache (60%). The students consulted their textbooks (39%) and seniors or classmates (38%) for the medications. Antipyretics (71%), analgesics (65%), antihistamines (37%) and antibiotics (34%) were the most common self- medicated drugs. Of the respondents, 33% were unaware of the adverse effects of the medication and 5% had experienced adverse reactions. The majority (64%) of students advised medications to others, more often to family and friends.

CONCLUSION

The prevalence of self-medication among medical students is high, facilitated by the easy availability of drugs and information from textbooks or seniors. A significant number of students are unaware of the adverse effects of the medication that they themselves take and suggest to others. Therefore, potential problems of self-medication should be emphasised to the students.

Female Epispadiasis: A Case report

Isolated female epispadias without exstrophy is rare to see. It is often overlooked cause of incontinence in a female child. A case of isolated female epispadias without exstrophy in an 11-year-old girl who presented with primary urinary incontinence since birth is reported. She had never had a genitalia examination done by any treating clinician. On examination, she had a bifid clitoris and ill developed labia minora. Voiding cystourethrogram showed small sized bladder with no reflux. Bladder neck reconstruction was done transvesically, with tubularisation of urethra. The case report reflects the importance of physical examination in primary incontinence which can make an early diagnosis and treatment and prevent stigmata of incontinence. DOI: http://dx.doi.org/10.3126/jnps.v31i3.4415 J Nep Paedtr Soc 2011;31(3): 244-246

Barriers to the utilization of dental services in udaipur, India

OBJECTIVE

Regular home care and yearly dental check-ups are the best means of dental care. In spite of the information on dental care, many people fail to take these precautions. The objective of this study was to determine the barriers in regular dental care and home care and to assess their association with age, sex, education and income.

MATERIALS AND METHODS

A cross-sectional survey was conducted among 427 randomly selected individuals, 248 males and 179 females. Data were collected by a pre-tested, self-administered 14 question questionnaire. The answer "very much" was scored as one, "to some degree" as two and "not at all" as three. The data was described and analyzed by frequency distribution and chi square test with P<0.05 level of significance. Logistic regression was used to investigate the association between dental visits with age, sex and education. Correlation between income and dental visits was determined by Spearman's correlation coefficient.

RESULTS

The male group had more dental visits (P>0.05), but females experienced higher dental fear (P<0.001). The younger age group had more visits within one year in comparison to the older. Increase in education, decreases the barriers for regular dental care. Income had a significantly negative correlation with dental visit (P=0.02).

CONCLUSION

Our findings suggest that males believed in having regular dental care. Cost of the treatment also affected the dental visits, but the distance they had to travel to get the dental treatment was not much significant. Above all, felt need had a major impact on the dental visits.

Effect of annealing ambient on performance and reliability of low pressure chemical vapor deposited oxides for thin film transistors

The performance and reliability of low pressure chemical vapor deposited (LPCVD) oxides subjected to oxidizing, inert and nitriding annealing ambients is characterized both at low temperature (600°C) and high temperature (950°C). The oxidizing ambient results in worse initial interface state density and charge to break down. We attribute this to the interfacial stress developed during the oxidation, due to the volume mismatch between Si and SiO2. The C-V measurements on poly-Si substrate capacitors and the charge pumping measurements on poly-Si thin film transistors (TFTs) indicate lower trap density for inert and nitriding ambients. The TFTs with inert anneal exhibit lower bias temperature instability compared to oxidizing ambient.

Awareness of Consumer Protection Act among Doctors in Udaipur City, India

OBJECTIVE

To compare the awareness of provisions of consumer protection act among dental and medical professionals in Udaipur city, Rajasthan, India.

MATERIALS AND METHODS

In a cross sectional study, a total of 448 professionals (253 males, 195 females) belonging to dental (222) and medical (226) categories were surveyed using a self administered structured questionnaire. The questionnaire comprised of 22 questions about the awareness of consumer protection art (CPA) and whether these professionals were following the recommendations of CPA. The student's t-test, ANOVA test, and Scheffe's test were used as tests of significance.

RESULTS

The awareness scores were significantly higher for medical professionals compared with those of dental professionals. Similarly, postgraduates showed more awareness in both the professions and it was found that private practitioners significantly have more awareness than the academic sector.

CONCLUSION

Though medical professionals have more awareness of CPA compared to dental professionals, considering the present scenario, better knowledge of CPA is necessary for both professionals in order to be on the safer side.

Health status of siblings of hospitalized children

OBJECTIVE

To study health status of siblings of children hospitalized for various diseases.

METHODS

A total of 308 siblings of 200 hospitalized children were studied by detailed history, anthropometry, physical examination and relevant laboratory tests.

RESULTS

Only 43.83% siblings were fully immunized, 25.32% partially and 30.85% were totally unimmunized. Normal nutritional status was seen in 20.43% siblings; 26.95% had grade 1, 25.64% grade II, 24.02% grade III and 2.92% had grade IV malnutrition. Various morbid conditions were observed in siblings, the common ones were vit. A deficiency (22.40%), worm infestation (21.42%), anemia (19.15%), dental caries (13.63%), ARI (13.31%), diarrhoea (12.01%), malaria (7.46%) and scabies (7.14%).

CONCLUSION

The siblings of hospitalized children are in a high-risk group as they share same environment and nutrition. They have various ailments in various stages of severity. The health screening of such children will have a positive impact in promoting health and diagnosing diseases at an early stage.

Should patients with asymmetrical noise-induced hearing loss be screened for vestibular schwannomas?

The Peterborough ENT department receives many referrals for MoD personnel who have suffered hearing loss from occupational noise exposure. Those patients with asymmetrical sensorineural hearing loss are routinely screened for vestibular schwannomas by MRI scanning. Scan reports from the past 5 years have been reviewed and out of 152 scans, four revealed vestibular schwannomas giving a pick-up rate of 2.5%, which compares favourably with other published pick-up rates. Review of the audiograms in these cases suggests that they can be misleading in this context. The conclusion is that patients with noise-induced asymmetrical hearing loss should be screened for acoustic neuromas.

Bipolar scissors versus cold dissection for pediatric tonsillectomy--a prospective, randomized pilot study

OBJECTIVE

To evaluate bipolar scissors tonsillectomy by comparing it with traditional cold dissection tonsillectomy. The outcome measures used were: (1) intra-operative bleeding; (2) operative time; (3) post-operative pain; and (4) complication rates including reactionary and secondary hemorrhage.

METHOD

A prospective, randomized multiunit study involving three teaching hospitals in Belfast. Fifty consecutive children aged 10-16 years undergoing tonsillectomy for recurrent or chronic tonsillitis, between March 2000 and September 2000 were recruited as a subgroup of 200 patients selected for this study. These children were analysed separately from the adults, in a pilot study for the above parameters.

RESULTS

The mean age of the study population was 14.3 years. Sixty-eight percent of the children were girls. Median intra-operative blood loss was 6 ml for bipolar scissors tonsillectomy and 86 ml for cold dissection tonsillectomy (P<0.001). The median operative time was 10.5 min for bipolar scissors tonsillectomy compared to 14.5 min for the cold dissection method (P=0.001). There was no statistically significant difference in the pain scores between the two methods (P>0.05). The overall reactionary hemorrhage rate was 4% while the overall secondary hemorrhage rate was 14%. The hospital readmission rate was 4%. The reactionary and secondary hemorrhage rates were unaffected by the surgical method.

CONCLUSIONS

This pilot study has shown that bipolar scissors tonsillectomy is a relatively safe technique in children aged 10-16 years with a similar morbidity to the cold dissection method. Its use is associated with a significant decrease in surgical time and blood loss compared to the cold dissection method. These advantages make it a favourable instrument for pediatric tonsillectomy especially in this age group.

Chromobacterium violaceum infection: A rare but frequently fatal disease

The authors report a rare case of Chromobacterium violaceum infection in a 2-month-old child. She presented with an apparently localized abscess, which appeared to respond well to therapy. However, the infection recurred later with a fulminant course. The organism frequently is dismissed as a contaminant or not identified properly, and the fatality rates are high. A high degree of awareness about this infection needs to be created, especially among pediatricians and pediatric surgeons, because children appear to be infected more commonly than adults, and aggressive therapy is needed to save these patients.

Bipolar scissors versus cold dissection tonsillectomy: a prospective, randomized, multi-unit study

OBJECTIVE

To evaluate bipolar scissors tonsillectomy by comparing it with traditional cold dissection tonsillectomy.

STUDY DESIGN

A prospective, randomized, multi-unit study.

SETTINGS

Belfast City Hospital, Royal Victoria Hospital Belfast, and Ulster Hospital Dundonald.

PATIENTS

Two hundred consecutive patients undergoing tonsillectomy for recurrent or chronic tonsillitis between March 2000 and September 2000.

OUTCOME MEASURES

(1) Intraoperative bleeding, (2) operative time, (3) postoperative pain, and (4) complication rates, including primary and secondary hemorrhage.

RESULTS

Seventeen patients were excluded from the study for various reasons. The mean age of the study population was 22 years (range, 10-54 y). Seventy-two percent of patients were female. Twenty-seven percent of patients were children aged 16 years or under. Median intraoperative blood loss was 5 mL for bipolar scissors tonsillectomy and 115 mL for cold dissection tonsillectomy (P < .001). The mean operative time was 13 minutes for bipolar scissors tonsillectomy compared with 20 minutes for the cold dissection method (P < .001). There was no statistically significant difference in the pain scores between the two methods (independent samples t = 1.35; P > .05). The overall primary hemorrhage rate was 2.1%, whereas the overall secondary hemorrhage rate was 16.9%. The hospital readmission rate was 10.3%. The primary and secondary hemorrhage rates were unaffected by the surgical method.

CONCLUSIONS

Bipolar scissors tonsillectomy is a safe technique with a similar morbidity to the cold dissection method. Its use is associated with a significant decrease in both surgical time and blood loss compared with the cold dissection method.

Spontaneous biliary perforation presenting as gastric outlet obstruction

Spontaneous biliary perforation (SBP) is a rare, surgically correctable cause of jaundice in neonates. The presenting feature is usually biliary ascites, and in rare cases, biliary peritonitis. This article reports a case of SBP, which presented with features of gastric outlet obstruction, leading to an erroneous preoperative diagnosis. Most probably this is the first report of such an unusual presentation of SBP. The child underwent exploratory laparotomy and a bilio-enteric bypass with drainage of the right subhepatic space, which led to a prompt resolution of the symptoms.

Etiologic and early marker studies in the prostate, lung, colorectal and ovarian (PLCO) cancer screening trial

The Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial, which is randomizing 74,000 screening arm participants (37,000 men, 37,000 women; ages 55-74) and an equal number of nonscreened controls, is a unique setting for the investigation of the etiology of cancer and other diseases and for the evaluation of potential molecular markers of early disease. At entry, baseline information is collected by questionnaire on dietary intake, tobacco and alcohol use, reproductive history (for women), family history of cancer, use of selected drugs, and other selected risk factors. Blood samples collected at the baseline screening exam are aliquoted to serum, plasma, red blood cell, and buffy coat fractions. At the next two annual screening visits, serum samples are collected. At the third annual reexamination, cryopreserved whole blood is obtained, in addition to serum, plasma, red blood cell, and buffy coat fractions. At the fourth and fifth years, serum, plasma, and buffy coat are collected. All blood samples are shipped to a central repository for long-term storage at -70 degrees C. Dietary questionnaires and buccal cells for DNA analysis are obtained from nonscreened controls. Cancer cases are identified through annual follow-up questionnaires, and all deaths are identified through vital status tracing mechanisms. Procedures are being developed to obtain archival pathologic material for selected cases of cancer and related diseases. Initial investigations are focusing on the etiology of colorectal cancer and on the operative characteristics of tests for the early detection of colorectal and prostate cancer.

Epidermoid cyst of the submandibular gland

Primary epidermoid cyst of the salivary gland is extremely rare and has only been reported once in the parotid gland A case of epidermoid cyst of the submandibular gland is presented, which required excisional biopsy for the diagnosis. Such excision is also curative.

Mediation of Cryptosporidium parvum infection in vitro by mucin-like glycoproteins defined by a neutralizing monoclonal antibody

The protozoan parasite Cryptosporidium parvum is a significant cause of diarrheal disease worldwide. Attachment to and invasion of host intestinal epithelial cells by C. parvum sporozoites are crucial steps in the pathogenesis of cryptosporidiosis. The molecular basis of these initial interactions is unknown. In order to identify putative C. parvum adhesion- and invasion-specific proteins, we raised monoclonal antibodies (MAbs) to sporozoites and evaluated them for inhibition of attachment and invasion in vitro. Using this approach, we identified two glycoproteins recognized by 4E9, a MAb which neutralized C. parvum infection and inhibited sporozoite attachment to intestinal epithelial cells in vitro. 4E9 recognized a 40-kDa glycoprotein named gp40 and a second, >220-kDa protein which was identified as GP900, a previously described mucin-like glycoprotein. Glycoproteins recognized by 4E9 are localized to the surface and apical region of invasive stages and are shed in trails from the parasite during gliding motility. The epitope recognized by 4E9 contains alpha-N-acetylgalactosamine residues, which are present in a mucin-type O-glycosidic linkage. Lectins specific for these glycans bind to the surface and apical region of sporozoites and block attachment to host cells. The surface and apical localization of these glycoproteins and the neutralizing effect of the MAb and alpha-N-acetylgalactosamine-specific lectins strongly implicate these proteins and their glycotopes as playing a role in C. parvum-host cell interactions.

Rapid activation of lymph nodes and mononuclear cell HIV expression upon interrupting highly active antiretroviral therapy in patients after prolonged viral suppression

OBJECTIVE

To compare the architecture and HIV-1 RNA and Gag p24 protein expression in lymph nodes (LN) excised from individuals during chronic highly active antiretroviral therapy (HAART) with LN removed from the same patient after plasma virus rebound following the interruption of HAART.

MATERIALS AND METHODS

Six HIV-1-infected patients on HAART, with CD4 cell counts greater than 350 cells/microl, and plasma HIV-1 RNA less than 50 copies/ml, underwent inguinal LN excision upon discontinuation of HAART, and again after rebound of plasma virus. Lymph nodes were evaluated by immunohistochemical staining for Gag p24 antigen and Ki67, in-situ hybridization for HIV-1 RNA and H3-histone, and transmission electron microscopy (TEM).

RESULTS

LN at baseline were quiescent to mildly hyperplastic and generally contained more primary than secondary follicles. Only one LN had detectable follicular dendritic cell (FDC)-associated p24 antigen, none had HIV RNA. Few mononuclear cells (MNC) expressed RNA or p24 antigen. Plasma virus at the second biopsy ranged from 329 to 3.2 x 10(6) copies/ml. CD4 cell count decline ranged from 5 to 51% during drug hiatus, and was greatest in patients with highest viral rebound. Four of six of the second LN were more hyperplastic than the initial LN, two showed paracortical hyperplasia. MNC expression of HIV RNA in the second LN paralleled the level of plasma viremia. Increased Ki67 and H3-histone signal occurred in the second LN.

CONCLUSION

Quiescent LN from individuals on HAART rapidly become hyperplastic and activated within 1-2 months after treatment interruption. As in acute HIV infection, virus expression by LN MNC parallels the rebound in plasma viremia and fall in CD4 cell count.

Paediatric airway endoscopy

OBJECTIVES

To review all paediatric endoscopies performed in a tertiary referral unit over a three-year period.

METHODS OF STUDY

Retrospective analysis of case-notes of all paediatric endoscopies performed between May 1993 and June 1996.

RESULTS

333 paediatric airway endoscopies were performed on 146 children, of which 52% were GP referrals and the remainder secondary referrals. 70% were diagnostic endoscopies, 30% therapeutic procedures, with the commonest indication being stridor and respiratory distress (82%). Routine chest radiographs, lateral neck X-rays, and barium swallows were unhelpful in the management of the commoner upper-airway conditions. The commonest findings were laryngomalacia (44%) and subglottic stenosis (22%) and 17% of all cases had multiple airway abnormalities. Tracheotomy was performed on 18.4%, laryngotracheoplasty on 7.5%, and laryngotracheal reconstruction on 2.5%. There were no major complications in this series.

CONCLUSIONS

All children with airway symptoms should have a thorough rigid-endoscopic evaluation of their upper and lower airways. Radiology has a limited role in the diagnosis of the more common airway pathologies. These patients need to be assessed and managed in regional centres.

A risk-benefit assessment of interleukin-2 as an adjunct to antiviral therapy in HIV infection

Immunomodulation has become a major focus of HIV research in an effort to augment, boost or restore the patient's damaged immune system. Recombinant interleukin-2 is currently being studied in phase II/III trials in HIV-infected patients. Several clinical studies have demonstrated that intermittent regimens are associated with marked rises in CD4+ cell counts without an increase in viral load. Most of these studies employ 5 consecutive days of interleukin-2 therapy by continuous intravenous infusion or subcutaneous injection, repeated every 8 weeks. An alternative strategy is the daily administration of low doses of interleukin-2, but clinical experience with this regimen is limited. Interleukin-2 administration can adversely affect virtually every organ system, requiring aggressive supportive care. A variety of administration strategies and interventions are being evaluated to minimise toxicity. Currently, no clinical end-point data are available for interleukin-2 in HIV-infected patients. Until phase III studies are completed, interleukin-2 can be used in the research setting as an immunomodulator and adjunct to antiretroviral therapy. Its potential to activate latently infected cells and promote HIV eradication from reservoir sites is also an important area for further study. If clinical benefit can be demonstrated, interleukin-2 could be useful as an adjunct to antiretroviral therapy if adverse effects can be minimised and therapy can be given infrequently on an outpatient basis.

HIV-1 and T cell dynamics after interruption of highly active antiretroviral therapy (HAART) in patients with a history of sustained viral suppression

Identifying the immunologic and virologic consequences of discontinuing antiretroviral therapy in HIV-infected patients is of major importance in developing long-term treatment strategies for patients with HIV-1 infection. We designed a trial to characterize these parameters after interruption of highly active antiretroviral therapy (HAART) in patients who had maintained prolonged viral suppression on antiretroviral drugs. Eighteen patients with CD4(+) T cell counts >/= 350 cells/microliter and viral load below the limits of detection for >/=1 year while on HAART were enrolled prospectively in a trial in which HAART was discontinued. Twelve of these patients had received prior IL-2 therapy and had low frequencies of resting, latently infected CD4 cells. Viral load relapse to >50 copies/ml occurred in all 18 patients independent of prior IL-2 treatment, beginning most commonly during weeks 2-3 after cessation of HAART. The mean relapse rate constant was 0.45 (0.20 log(10) copies) day(-1), which was very similar to the mean viral clearance rate constant after drug resumption of 0.35 (0.15 log(10) copies) day(-1) (P = 0.28). One patient experienced a relapse delay to week 7. All patients except one experienced a relapse burden to >5,000 RNA copies/ml. Ex vivo labeling with BrdUrd showed that CD4 and CD8 cell turnover increased after withdrawal of HAART and correlated with viral load whereas lymphocyte turnover decreased after reinitiation of drug treatment. Virologic relapse occurs rapidly in patients who discontinue suppressive drug therapy, even in patients with a markedly diminished pool of resting, latently infected CD4(+) T cells.

Generation of a polyclonal Fab phage display library to the protozoan parasite Cryptosporidium parvum

We had developed a technology for creation of recombinant polyclonal antibody libraries, standardized perpetual mixtures of polyclonal whole antibodies for which the genes are available and can be altered as desired. We report here the first phase of generating a polyclonal antibody library to Cryptosporidium parvum, a protozoan parasite that causes severe disease in AIDS patients, for which there is no effective treatment. BALB/c mice, immunized by neonatal oral infection with oocysts followed by intraperitoneal immunization with a sporozoite/oocyst preparation of C. parvum, were used for construction of a Fab phage display library in a specially-designed bidirectional vector. This library was selected for reactivity to an oocyst/sporozoite preparation, and was shown to be antigen-specific and diverse. Following mass transfer of the selected variable region gene pairs to appropriate mammalian expression vectors, such anti-C. parvum Fab phage display libraries could be used to develop chimeric polyclonal antibody libraries, with mouse variable regions and human constant regions, for passive immunotherapy of C. parvum infection.

Use of a photoactivatable taxol analogue to identify unique cellular targets in murine macrophages: identification of murine CD18 as a major taxol-binding protein and a role for Mac-1 in taxol-induced gene expression

Taxol, a potent antitumor agent that binds beta-tubulin and promotes microtubule assembly, results in mitotic arrest at the G2/M phase of the cell cycle. More recently, Taxol was shown to be a potent LPS mimetic in murine, but not in human macrophages, stimulating signaling pathways and gene expression indistinguishably from LPS. Although structurally unrelated to LPS, Taxol's LPS-mimetic activities are blocked by inactive structural analogues of LPS, indicating that despite the species-restricted effects of Taxol, LPS and Taxol share a common receptor/signaling complex that might be important in LPS-induced human diseases. To identify components of the putatively shared Taxol/LPS receptor, a novel, photoactivatable Taxol analogue was employed to identify unique Taxol-binding proteins in murine macrophage membranes. Seven major Taxol-binding proteins, ranging from approximately 50 to 200 kDa, were detected. Although photoactivatable Taxol analogue failed to bind to CD14, the prominent Taxol-binding protein was identified as CD18, the approximately 96-kDa common component of the beta2 integrin family. This finding was supported by the concomitant failure of macrophage membranes from Mac-1 knockout mice to express immunoreactive CD18 and the major Taxol-binding protein. In addition, Taxol-induced IL-12 p40 mRNA was markedly reduced in Mac-1 knockout macrophages and anti-Mac-1 Ab blocked secretion of IL-12 p70 in Taxol- and LPS-stimulated macrophages. Since CD18 has been described as a participant in LPS-induced binding and signal transduction, these data support the hypothesis that the interaction of murine CD18 with Taxol is involved in its proinflammatory activity.

Antifungal activity of voriconazole (UK-109,496), fluconazole and amphotericin B against hematogenous Candida krusei infection in neutropenic guinea pig model

Voriconazole (UK-109,496) is a new triazole with in vitro activity against a wide spectrum of fungi including yeasts intrinsically resistant to fluconazole such as Candida krusei. In this study the efficacy of voriconazole was compared to amphotericin B and fluconazole in a neutropenic guinea pig model of hematogenously disseminated C. krusei infection. In guinea pigs, neutropenia was established by using cyclophosphamide (intraperitoneally, i.p., 100 mg/kg on day 1 and 4), and dexamethasone (orally, 2 mg/kg/day, for 8 days). Neutropenic guinea pigs were infected with 0.5 ml of yeast cell suspension (1 x 10(8) CFU) intravenously. Challenged animals were treated with antifungals starting 1 h postinfection for 7 days. The animals were divided into five groups: untreated control, amphotericin B (1 mg/kg i.p. on alternate days), fluconazole (20 mg/kg orally twice daily), and voriconazole (two groups: 5 and 10 mg/kg orally twice daily) groups. Guinea pigs were sacrificed 1 day after the last treatment. Brain, liver, and kidneys were removed and weighed, tissues were homogenized and fungal burden determined by serial quantitative counts. Voriconazole at dosages of 5 or 10 mg/kg b.i.d. was shown to be significantly more efficacious than either amphotericin B or fluconazole in eradicating C. krusei from brain, liver and kidney tissue. These data indicate that voriconazole could be efficacious for the treatment of infections caused by fluconazole-resistant Candida, such as C. krusei.

Epignathus: a germ-cell tumour presenting as neonatal respiratory distress

A full-term neonate developed acute upper airway obstruction immediately after birth secondary to a polypoidal mass in the oropharynx. After the child's airway had been secured, the mass was excised and found to be a nasopharyngeal teratoma, a rare congenital germ cell tumour which is frequently associated with other congenital malformations. It is sometimes possible to diagnose these tumours in utero, thereby enabling appropriate precautions to be taken during the delivery, otherwise if the diagnosis is unknown, then it is essential for any attending clinician to urgently secure the airway by means of either intubation or tracheostomy. Such a case is presented with a review of the possible management options. This case emphasises the fact that although many conditions are uncommon, the total incidence of rare conditions is surprisingly high, and that care needs to be taken at all times in the management of patients, in order not to overlook such life-threatening diagnoses.

Vancomycin-resistant enterococcal colonization in nonhospitalized HIV-infected patients

We studied fecal colonization with vancomycin-resistant enterococci (VRE) in 89 HIV-infected nonhospitalized patients ages 24 to 62 years, including 70 (79%) men (including 41 homosexual and 5 bisexual men) and 19 (21%) women. Of the 89 patients, 61 (69%) were black, 25 (28%) Hispanic, and 3 (3%) white; 53 (60%) had history of ongoing or recent antibacterial therapy with trimethoprim/sulfamethoxazole (29), clarithromycin (18), amoxicillin (7), ofloxacin (3), and metronidazole, doxycycline, dicloxacillin, and cephalexin (1 each). VRE were not isolated from any of the patients studied.

Country-specific constancy by age in cagA+ proportion of Helicobacter pylori infections

Helicobacter pylori strains may be either cagA+ or cagA-, and in logitudinal studies, infection with a cagA+ strain has been associated with increased risk for the development of atrophic gastritis and cancer of the distal stomach. We sought to determine the relative proportion of strains producing CagA in different geographic locales, and the extent to which CagA seroprevalence varied in countries with different gastric and esophageal cancer rates. Using an enzyme-linked immunosorbent assay (ELISA) to detect serum IgG to CagA, we examined sera from 468 asymptomatic H. pylori-infected adults from Canada, Peru, China, Thailand, The Netherlands and 3 different ethnic groups in New Zealand. The CagA seroprevalence in Peru and Thailand (82.2% and 78.8%, respectively) were each substantially higher than for the Chinese (37.9%), Canadian (41.9%), Dutch (39.0%) and New Zealand (28.2%) subjects, but within each population, rates were relatively constant across gender and age groups. Reported gastric but not esophageal cancer rates for the 8 studied populations were significantly associated with H. pylori seroprevalence. Variation in CagA positivity rates was not significantly associated with variation in either gastric or esophageal cancer rates. Our data suggest that CagA seroprevalence is not the major factor influencing gastric cancer rates.

Country-specific constancy by age in cagA+ proportion of Helicobacter pylori infections

Helicobacter pylori strains may be either cagA+ or cagA-, and in logitudinal studies, infection with a cagA+ strain has been associated with increased risk for the development of atrophic gastritis and cancer of the distal stomach. We sought to determine the relative proportion of strains producing CagA in different geographic locales, and the extent to which CagA seroprevalence varied in countries with different gastric and esophageal cancer rates. Using an enzyme-linked immunosorbent assay (ELISA) to detect serum IgG to CagA, we examined sera from 468 asymptomatic H. pylori-infected adults from Canada, Peru, China, Thailand, The Netherlands and 3 different ethnic groups in New Zealand. The CagA seroprevalence in Peru and Thailand (82.2% and 78.8%, respectively) were each substantially higher than for the Chinese (37.9%), Canadian (41.9%), Dutch (39.0%) and New Zealand (28.2%) subjects, but within each population, rates were relatively constant across gender and age groups. Reported gastric but not esophageal cancer rates for the 8 studied populations were significantly associated with H. pylori seroprevalence. Variation in CagA positivity rates was not significantly associated with variation in either gastric or esophageal cancer rates. Our data suggest that CagA seroprevalence is not the major factor influencing gastric cancer rates.

Expression of ets family of genes in systemic lupus erythematosus and Sjogren's syndrome

We have examined the expression of three members of the ets family of genes, ETS1, ETS2 and ERGB/Fli-1, in lymphocytes from patients with systemic lupus erythematosus and in two murine autoimmune model systems. The ERGB/Fli-1 gene is expressed at a higher level in lymphocytes from autoimmune disease patients than healthy individuals. In addition, we found that the ERGB/Fli-1 gene expression is higher in splenic T-cells from lupus prone mice and in infiltrating lymphocytes in the salivary glands of HTLV-I tax transgenic mice. Taken together, these results suggest that the elevated expression of the ERGB/Fli-1 gene in lymphocytes may be a prelude to the development of autoimmune diseases.