Recurrent asthma exacerbations: co-existing asthma and common variable immunodeficiency

Common variable immunodeficiency is characterized by impaired B-cell differentiation and defective immunoglobulin production manifesting as recurrent respiratory tract infections. While the condition can masquerade as asthma, late diagnosis of CVID in known asthmatic is rarely reported.

We present the case of a 43-year-old lady with recurrent episodes of wheeze, cough, sinusitis and multiple lower respiratory tract infections. Transiently responsive to antibiotics and steroids. These episodes had been occurring for many years and she had a longstanding clinical diagnosis of asthma.

As part of her work up for recurrent respiratory tract infections a CT thorax was performed and demonstrated bronchiectasis. Further tests including Immunoglobulin levels revealed critically low IgG, IgM, and IgA levels. Immunoglobulin replacement therapy was commenced with a reduction in exacerbation frequency and severity, and objective improvement of asthma control. Subsequent lung function tests demonstrated reversible airflow limitation (obstructive lung function with 13% reversibility in FEV₁ post-bronchodilator) consistent with asthma.

Our case illustrates the importance of searching for alternate and co-existent diagnoses in patients diagnosed with asthma who are unresponsive to conventional therapy. We believe that serum immunoglobulin measurement should form a component of such a workup.

O64: GENOMIC PROFILING USING CIRCULATING NUCLEIC ACIDS IN STAGE IV MELANOMA PATIENTS RECEIVING IMMUNOTHERAPY REVEALS A NOVEL GENE AMPLIFICATION LANDSCAPE AND ALLOWS FOR DETECTION OF ACTIONABLE GENE MUTATIONS

Introduction

Serial monitoring for disease progression and therapeutic efficacy at the molecular level in metastatic melanoma is hampered by a lack of reliable blood borne biomarkers. Molecular profiling of melanoma tumours is almost impractical in metastatic disease due to risks of procedure related morbidity and sampling inefficiency in representing tumour heterogeneity. Cell free DNA allows monitoring of molecular changes in melanoma over the course of immunotherapy. We investigated the utility of somatic mutation and gene amplification analyses in melanoma patients receiving immunotherapy.

Method

Cell free DNA was extracted from plasma using a QIAamp Circulating Nucleic Acid Kit (Qiagen). Pathway focused profiling of somatic mutation status was performed by ARMs PCR using QBiomarker Somatic Mutation PCR Arrays (Qiagen). Gene amplification analysis was performed by Real Time Quantitative PCR (Roche) using RT2 Profiler PCR Arrays (Qiagen).

Result

A total of twenty patients with stage IV melanoma receiving immunotherapy were enrolled in this study. The BRAF p.V600E mutation was detected in the cfDNA of 80% of BRAF positive patients. Cell free DNA was also profiled for a total of 84 genes of the cancer inflammation and immunity pathway. There was a significant difference in the copy numbers of several genes (CTLA-4, CXCL12, CXCL5, IDO1, TGFB, IFNG, IL4, PTGS2, AICDA, HLA-A, CCL4, ACKR3, TP53, MYC) between patients with progressive disease and therapeutic response (n=20, p < 0.05).

Conclusion

We postulate that cell free DNA pathway focused somatic mutation and gene amplification analyses may be useful in evaluating disease progression and therapeutic response.

Take-home message

Genomic analysis of circulating nucleic acids may be useful in evaluating disease progression and therapeutic response in metastatic melanoma.

Abstract P6-06-01: Analyzing the physical and functional protein interaction landscape of breast cancer

A key unanswered question in cancer genetics is how different mutations, dispersed across a multitude of genes, elicit similar pathology and patient outcomes. The answer may lie in understanding the molecular networks and protein complexes (i.e. signaling pathways, chromatin architecture, etc) in cancer and mapping mutated genes into the complexes and pathways in which they function. Determining how systematic interaction networks are wired in cancer cells and how different mutations perturb these networks will guide the search for new cancer genes and provide a platform for integrating patient data to make biological and clinical predictions more accurate. The goal of this study is to uncover the comprehensive protein-protein interaction networks and pathways in various breast cancer subtypes to better understand how mutated cancer genes and genomes hijack and re-wire pathways and complexes during the course of breast tumorigenesis.

Here we catalog protein-protein interactions for 40 genes recurrently mutated in breast cancer, using affinity purification and mass spectrometry. To identify co-associated proteins, cDNA clones expressing each protein were tagged with 3xFLAG at either N or C-terminus and introduced into MCF10A (non-tumorigenic “healthy” control), MCF7 (luminal A subtype), and MDA-MB-231 (claudin-low) cells using doxycycline-inducible lentiviral vectors. For proteins with prevalent pathogenic mutations (e.g. PIK3CA-H1047R, BRCA1-C61G), mutant cDNA clones were also analyzed in parallel. Our interaction network reveals subtype and mutation-specific protein-protein interactions, many of which are not previously reported. Given that genes encoding components of a protein complex or a biological pathway often share similar phenotype upon genetic perturbation, we genetically knocked out genes interacting with DNA damage response (DDR) proteins using CRISPR/Cas9, and found multiple novel interacting genes whose knockout results in significant PARPi (olaparib) and/or cisplatin sensitivity. This result not only functionally validates the physical protein interactions, but also demonstrates that our interactome mapping approach can helps identify newdruggable vulnerabilities in cancer cells.

We anticipate the breast cancer interactome study will uncover aberrant pathways and protein complexes uniquely operating in breast cancer cells, and thus pinpoint proteins that may potentially serve as distinct biomarkers or therapeutic targets for tumors having the same or similar subtypes and/or genomic mutations.

Citation Format: Kim M, Kim K, Tutuncuoglu B, Soucheray M, Swaney D, Zheng F, Park J, O'Leary P, Coppé J-P, van 't Veer L, Ashworth A, Ideker T, Krogan N. Analyzing the physical and functional protein interaction landscape of breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-06-01.

A new approach for the automatic evaluation of the solidification structure in steel using orientational entropy filtering

We present a new method for the automatic evaluation of the dendritic solidification structure in metallurgical micrographs of solidified steel. The evaluation of the microstructural parameters such as the primary dendrite arm spacing and the primary grain size are of high importance due to their direct relationship with the internal quality and mechanical properties of the cast product. Given the repeated geometric features in the micrographs and the regular pattern in colour intensity, we applied a filter mask to determine the local entropies within the masks in order to detect the centre coordinates of each individual dendrite. The orientation of the dendrites was determined by rotating the filter mask over each pixel to find the orientation which corresponds to the lowest entropy value. The segmentation of the microstructure was then performed via Delaunay tessellation and subsequent transformation of the triangular mesh into a rectangular grid, enabling the determination of the desired microstructural parameters.

Mesenteric vasculitis in adults with Henoch-Schonlein purpura: a not-so-benign condition

INTRODUCTION

The gastrointestinal manifestations of Henoch-Schonlein purpura (HSP) are well characterised, but their recognition can be difficult when they occur in isolation. Furthermore, HSP can run a more serious course in adults, compared to children, in whom the disease usually occurs.

MATERIALS AND METHODS

We describe two cases that illustrate the challenges of HSP with mesenteric vasculitis and the outcome in adults.

CONCLUSION

Although self-limiting in most patients, the outcome of HSP in adults can be far from benign and even fatal.

Australian study on public knowledge of human genetics and health

AIMS

This study was designed to obtain data on public understanding of genetic concepts in the adult population of Western Australia. It explored knowledge of genetic risk of disease, inheritance, biology, determinism, and factors that predict relatively higher genetic knowledge within the general population.

METHOD

A cross-sectional telephone survey of 1,009 respondents.

RESULTS

Most members of the Western Australian community are aware of basic genetic concepts and the link between genes, inheritance, and risk of disease. Significantly fewer understand the biological mechanisms underlying these concepts and there was some misconception around the meaning of 'increased genetic risk'. The odds of higher genetic knowledge (>19 out of 24 questions correct) were greater among those with 12 years or more education (OR = 3.0), those aged 18-44 years (OR = 2.3), women (OR = 2.0), those with annual household income of AUD 80,000 or more (OR = 1.8), and those who had talked with someone (OR = 1.7) or searched the internet (OR = 1.6) for information on genes and health.

CONCLUSIONS

This study provides evidence of an association between social location and public knowledge of human genetic concepts related to health and disease. This is consistent with previous findings and raises questions about the acquisition of textbook genetics knowledge within socio-cultural contexts. The impact of misconceptions about genetic concepts on the uptake of preventive health behaviors requires further investigation, as does the level of genetics knowledge that is required to empower informed participation in individual and societal decisions about genetics and health.

Economic evaluation of the familial cancer programme in Western Australia: predictive genetic testing for familial adenomatous polyposis and hereditary non-polyposis colorectal carcinoma

AIM

To evaluate costs and outcomes of genetic testing for familial colorectal cancer through services provided by Genetic Services of Western Australia (GSWA).

METHODS

Costs and outcomes of predictive DNA-based testing for inherited colorectal cancers (CRC) were assessed, specifically for familial adenomatous polyposis (FAP) and hereditary non-polyposis CRC (HNPCC) using a decision-analysis model. Costs were assigned according to standards of care in Western Australia (WA). Cancer risks and the efficacy of surveillance on long-term outcomes were derived from the published literature.

RESULTS

The cost-effectiveness of genetic testing was compared in first-degree relatives of known mutation carriers who have a 50% risk of carrying the mutated gene (intervention group) to individuals with the same risk but who do not undergo a genetic test (control subjects). Compared with control subjects undergoing the same high-level surveillance and surgery, the FAP and HNPCC intervention groups provided total savings of 13,390 US dollars and 14,783-15,460 per person (males-females), respectively. HPNCC mutation carriers also gained 1 CRC-free year. Compared to control subjects having only population surveillance, individuals in the FAP intervention group delayed the onset of CRC by 40 years for a net cost of 9,042 US dollars. Individuals in the HNPCC intervention group delayed the onset of CRC by 8 years at a net cost of 12,141 US dollars for males and 12,596 US dollars for females.

CONCLUSIONS

Genetic testing for familial CRC in WA allows targeted surveillance for mutation carriers, which ensures the efficient use of resources and reduces cancer-related morbidity, if clinical recommendations for intervention are adopted.

Subcutaneous glucose sensor values closely parallel blood glucose during insulin-induced hypoglycaemia

AIMS

To assess the accuracy of the Minimed continuous glucose monitoring system (CGMS) in estimating blood glucose concentration during a controlled reduction in blood glucose.

RESEARCH DESIGN AND METHODS

We studied nine adolescent diabetics (age 14 +/- 1.5 years) wearing the CGMS during hyperinsulinaemic hypoglycaemic clamp studies. The glucose values obtained by the CGMS were compared with the venous blood samples taken during the studies and measured at the bedside using a glucose oxidase technique.

RESULTS

Blood glucose was lowered from euglycaemia to a mean of 2.8 mmol/l over 120 min and maintained at that level for a further 40 min. A total of 429 paired glucose measurements were available for analysis. Analysis using weighted Deming regression and t-tests revealed small differences between the methods, with blood glucose levels slightly higher than interstitial fluid levels. The mean difference across all values was 0.13 mmol/l. The observed difference was greatest at blood glucose values < 3.3 mmol/l.

CONCLUSIONS

This study suggests that during a fall in systemic glucose the subcutaneous glucose sensor provides an accurate reflection of blood glucose. However, a small difference is apparent at blood glucose values < 3.3 mmol/l.

Modeling SSI financial eligibility and simulating the effect of policy options

This article simulates eligibility for Supplemental Security Income (SSI) among the elderly, analyzes factors affecting participation, and looks at the potential effects of various options to modify financial eligibility standards for the federal SSI program. We find that in the estimated noninstitutional elderly population of 30.2 million in the United States in 1991, approximately 2 million individuals aged 65 or older were eligible for SSI (a 6.6 percent rate of eligibility). Our overall estimate of the rate of participation among eligible elderly is approximately 63 percent, suggesting that more than a third of those who are eligible do not participate in the program. The results of our analysis of factors affecting participation among the eligible elderly show that expected SSI benefits and a number of demographic and socioeconomic variables are associated with the probability of participation. We also simulate the effects of various policy options on the poverty rate, poverty gap, annual program cost, the number of participants, and the average estimated benefits among participants. The simulations consider the potential effects of five policy alternatives: Increase the general income exclusion (GIE) from $20 to $80. Increase the earned income exclusion (EIE) from $65 to $260. Increase the federal benefit rate (FBR) by $50 for individuals and $75 for couples and eliminate the GIE. Increase the asset threshold to $3,000 for individuals and $4,500 for couples. Increase the asset threshold to $6,000 for individuals and $9,000 for couples. Using 1991 microdata from the Survey of Income and Program Participation (SIPP) matched to Social Security Administration administrative records and making adjustments reflecting aggregate program statistics, we present the results of our simulations for December 1999. The results show substantial variation in the simulated effects of the five policy alternatives along the various outcome dimensions considered. The simulated effects on the poverty gap of the elderly population range from a 7.9 percent reduction ("Increase the GIE from $20 to $80") to a 0.1 percent reduction ("Increase the EIE from $65 to $260"). All simulated interventions are expected to increase the rate of SSI participation among the elderly from a high of 20.3 percent ("Increase the GIE from $20 to $80") to a low of 0.5 percent ("Increase the EIE from $65 to $260"). We also find that the interventions that have greater estimated effects in terms of increased participation and reduced poverty tend to cost more. At the high end, we estimate that increasing the GIE from $20 to $80 could raise annual federal SSI cash benefit outlays by about 46 percent, compared with only 0.9 percent for increasing the EIE from $65 to $260. Similar to the EIE intervention, raising the resource thresholds by 50 percent would reduce the overall poverty gap of the elderly by only 0.2 percent, would increase SSI participation only modestly (by 1.3 percent), but would entail slightly higher program costs (by 1.4 percent). Increasing the asset threshold by 200 percent would have higher estimated effects on all three outcomes, but it would still be associated with relatively low increases in both costs and benefits. Finally, the simulated effects on the three key outcomes of increasing the FBR by $50 for individuals and $75 for couples, combined with eliminating the GIE, are relatively large but are clearly less substantial than increasing the GIE from $20 to $80. This work relies on data from the SIPP matched to administrative data on federal SSI benefits that provide a more accurate picture of SSI participation than has been feasible for previous studies. We simulate eligibility for federal SSI benefits by applying the program rules to detailed information on the characteristics of individuals and couples based on the rich array of demographic and socioeconomic data in the SIPP, particularly the comprehensive information SIPP provides on assets and monthly income. A probit model is estimated to analyze factors affecting participation among the eligible elderly. Finally, we conduct the policy simulations using altered program rules represented by the policy alternatives and predicted participation probabilities to estimate outcomes under simulated program rules. We compare those simulated outcomes to observed outcomes under current program rules. The results of our simulations are conditional on the characteristics of participants and eligibles in 1991, but they also reflect aggregate adjustments capturing substantial changes in overall participation and program benefit levels between 1991 and 1999.

Origins of skeletal pain: sensory and sympathetic innervation of the mouse femur

Although skeletal pain plays a major role in reducing the quality of life in patients suffering from osteoarthritis, Paget's disease, sickle cell anemia and bone cancer, little is known about the mechanisms that generate and maintain this pain. To define the peripheral fibers involved in transmitting and modulating skeletal pain, we used immunohistochemistry with antigen retrieval, confocal microscopy and three-dimensional image reconstruction of the bone to examine the sensory and sympathetic innervation of mineralized bone, bone marrow and periosteum of the normal mouse femur. Thinly myelinated and unmyelinated peptidergic sensory fibers were labeled with antibodies raised against calcitonin gene-related peptide (CGRP) and the unmyelinated, non-peptidergic sensory fibers were labeled with the isolectin B4 (Bandeira simplicifolia). Myelinated sensory fibers were labeled with an antibody raised against 200-kDa neurofilament H (clone RT-97). Sympathetic fibers were labeled with an antibody raised against tyrosine hydroxylase. CGRP, RT-97, and tyrosine hydroxylase immunoreactive fibers, but not isolectin B4 positive fibers, were present throughout the bone marrow, mineralized bone and the periosteum. While the periosteum is the most densely innervated tissue, when the total volume of each tissue is considered, the bone marrow receives the greatest total number of sensory and sympathetic fibers followed by mineralized bone and then periosteum. Understanding the sensory and sympathetic innervation of bone should provide a better understanding of the mechanisms that drive bone pain and aid in developing therapeutic strategies for treating skeletal pain.

Dynamic equilibria in the products of intramolecular Buchner additions of diazoketones to aryl rings bearing methoxy substituents

Rhodium carboxylate catalyzed aromatic addition reactions of a range of diazoketones bearing methoxy-substituted aryl rings have been explored. While the existence of norcaradiene-cycloheptatriene equilibria in related compounds is well established, the aromatic addition products in this study display more complex dynamic equilibria due to conjugation with the methoxy group; the experimental evidence for this is discussed in detail. In the azulenone products 21-26 derived from p-methoxy-substituted diazoketones 14-16, the diastereomers interconvert via a spiro intermediate 39. A related mechanistic process in the azulenones 43-46 derived from the o-methoxy-substituted diazoketones 17, 18 interconverts regioisomers, explaining the conflicting reports for the regioselectivity of the cyclization of diazoketone 1. With the m-methoxy-substituted diazoketone 19, involvement of the methoxy group through a different pathway results in fragmentation of the azulenone to form the tetralone 47. With the azulenones 21-26 exclusive trapping of the norcaradiene associated with the less thermodynamically stable diastereomers in a cycloadduct with N-phenylmaleimide is observed. Due to the presence of the activating methoxy substituent on the aromatic ring, the aromatic addition reactions of the diazoketones studied were not very sensitive to the nature of the rhodium catalyst.

Salivary, but not serum or urinary levels of progesterone are elevated after topical application of progesterone cream to pre-and postmenopausal women

OBJECTIVE

The use of topically applied micronised ('natural') progesterone as a substitute for synthetic oestrogens and progestogen preparations is controversial. The aim of this study was to examine the changes in blood and salivary concentrations of progesterone following a single topical application of a progesterone cream.

PATIENTS AND MEASUREMENTS

We investigated six premenopausal women in the luteal phase and six postmenopausal women to determine the short-term changes in serum, urinary and salivary progesterone concentrations following a single 64 mg topical application of micronised progesterone.

RESULTS

Serum progesterone concentrations did not increase during the first 3 hours after application of progesterone cream, however, salivary values rose significantly in both premenopausal and postmenopausal women, consistent with the view that progesterone is absorbed and transported through the body. Salivary progesterone concentrations were significantly elevated above basal levels by 30-60 minutes and reached peak levels at 1-4 h, with mean levels approximately fivefold higher in premenopausal, than in menopausal women.

CONCLUSIONS

Salivary progesterone measurements confirm that topically applied progesterone is absorbed, despite the lack of change in serum progesterone concentrations. However, at the dose administered, serum progesterone levels do not reach those observed after oral or vaginally delivered progesterone preparations. Higher doses may be required to induce biological responses within the endometrium.

Dendritic cells associated with plasmablast survival

A subset of myeloid dendritic cells is described which is associated with the ability of splenic and lymph node plasmablasts to survive and differentiate into plasma cells. Plasmablast-associated dendritic cells (PDC) are CD11c(high), DEC-205(-) and unlike conventional dendritic cells do not associate with T cells. The following findings suggest a requirement for PDC if plasmablasts are to differentiate to plasma cells. First, when large numbers of B cells are recruited into antibody responses and plasmablasts outgrow the PDC stroma, only those associated with PDC survive and differentiate into plasma cells. Conversely, if the number of PDC is increased by ligating their CD40, more plasmablasts survive on the expanded PDC stroma and differentiate into plasma cells. Finally, in T cell-deficient mice, the plasma cells that develop atypically in the T zones in response to thymus-independent antigens are associated with ectopic PDC.

What is the future for nurse executives?

This article describes the future role of nurse executives as designers of health care rather than respondents to internal and external environmental forces. The successful executives will be proactive, dedicated, and politically astute. These individuals will engineer vertical organizations that are empowered, fluid, and flexible. These new organizational skills will be developed through innovative executive educational programs designed at the master's and doctoral levels. Well-established executives from business, education, public health, medicine, administration, health systems, and education will become the faculty preparing these individuals. These programs will integrate other health care disciplines through an integrated and flexible approach to learning. The development of these roles will influence policy and decision making at all levels within health care.

A partnership for community-based nursing experience: Head Start/Harper College

In an effort to provide a meaningful community-based nursing experience for the students of William Rainey Harper College, a project was developed with the Community Economic Development Association of Cook County, Illinois to link second-year nursing students and clients in a Head Start program. The goals were designed to meet the needs of both the students and the Head Start clients. The students provided a portion of the health service plan for the Head Start families, and at the same time they received a comprehensive community/family learning experience. Throughout the second year of the nursing program the students followed their assigned family utilizing a unique integration of pediatric and psychiatric nursing concepts. The article will outline the project from development to completion of the first year of student involvement. It will address successes, failures, and changes made in the second year of the program.

T-independent type 2 antigens induce B cell proliferation in multiple splenic sites, but exponential growth is confined to extrafollicular foci

During the primary splenic response to the T-independent type 2 (TI-2) antigen (4-hydroxy-3-nitrophenyl) acetyl (NP)-Ficoll, small numbers of antigen-specific B cells have entered S phase of the cell cycle 24 h after intraperitoneal immunization. These are distributed in all splenic compartments (T zones, marginal zones, follicles, and red pulp), indicating early proliferation induced by NP-Ficoll does not require accessory signals delivered in a particular splenic microenvironment. Subsequently B blasts accumulate selectively in the outer T zone areas, but exponential growth leading to plasma cell production occurs only in extrafollicular foci. This growth peaks after 5 days, but 20% of peak numbers of antibody-containing cells are still present 3 months after immunization and 9% of these cells are proliferating. It is unclear if these late plasmablasts are sustained by self-renewal or continued recruitment of virgin cells into the response. Unlike TD and TI-1 responses NP-specific memory cells do not accumulate in the splenic marginal zones. The level of Cgamma3 switch transcripts increases during the first 24 h of the response, but does not increase further during exponential plasmablast growth.

Sleep, respiratory rate, and growth hormone in chronic neonatal lung disease

This study assessed whether respiratory rates (RRs) correlate with urinary growth hormone (U-GH) excretion and sleep architecture in infants with chronic neonatal lung disease (CNLD) in early (1 month), middle (6 months), and late (10 months) infancy. Twenty-three preterm infants (CNLD=16, controls=7) were studied on 51 occasions. CNLD infants were stratified according to mean non-REM sleep respiratory rate (NREM RR) in early infancy into "High RR CNLD" infants (mean NREM RR >2 SD higher than controls) and "Normal RR CNLD" infants (mean NREM RR within 2 SD of controls' mean). "High RR CNLD" infants (RR >45) had a lower mean birthweight (P=0.015), current weight (P=0.042), current length (P=0.02), and growth velocity in early infancy (grams/week gained: P=0.042) than "Normal RR CNLD" and control infants. Mean (95% CI) U-GH excretion (ng U-GH/g urinary creatinine) was higher in "High RR CNLD" infants in air or their usual O2 (1,932 [459, 3,406]) than "Normal RR CNLD" (394 [147, 642]) and controls (320 [147, 492]) (P=0.024). With resolution of tachypnea by mid-infancy, hemoglobin oxygen saturation (SaO2) >93%, mean growth parameters and U-GH excretion for the "High RR CNLD" group were not significantly different from "Normal RR CNLD" and control groups. CNLD infants demonstrated increased sleep efficiency (P=0.016), whereas controls had similar sleep efficiency between early and middle infancy (P=0.452). Mean percent time in REM sleep (REM%) and slow wave sleep (SWS%) were not significantly different between early and middle infancy and did not vary in relation to respiratory rate. We conclude that tachypneic infants with CNLD have slower growth and elevated U-GH excretion in early infancy. With resolution of tachypnea, growth improved, U-GH excretion decreased, and sleep consolidation occurred. An elevated U-GH in tachypneic CNLD infants may reflect stress, compromised nutrition (GH resistance), or a feedback loop involving a direct effect of GH on lung growth and repair.

Decreased epinephrine responses to hypoglycemia during sleep

BACKGROUND

In patients with type I diabetes mellitus, hypoglycemia occurs commonly during sleep and is frequently asymptomatic. This raises the question of whether sleep is associated with reduced counterregulatory-hormone responses to hypoglycemia.

METHODS

We studied the counterregulatory-hormone responses to insulin-induced hypoglycemia in eight adolescent patients with type I diabetes and six age-matched normal subjects when they were awake during the day, asleep at night, and awake at night. In each study, the plasma glucose concentration was stabilized for 60 minutes at approximately 100 mg per deciliter (5.6 mmol per liter) and then reduced to 50 mg per deciliter (2.8 mmol per liter) and maintained at that concentration for 40 minutes. Plasma free insulin, epinephrine, norepinephrine, cortisol, and growth hormone were measured frequently during each study. Sleep was monitored by polysomnography.

RESULTS

The plasma glucose and free insulin concentrations were similar in both groups during all studies. During the studies when the subjects were asleep, no one was awakened during the hypoglycemic phase, but during the final 30 minutes of the studies when the subjects were awake both the patients with diabetes and the normal subjects had symptoms of hypoglycemia. In the patients with diabetes, plasma epinephrine responses to hypoglycemia were blunted when they were asleep (mean [+/-SE] peak plasma epinephrine concentration, 70+/-14 pg per milliliter [382+/-76 pmol per liter]; P=0.3 for the comparison with base line), as compared with when they were awake during the day or night (238+/-39 pg per milliliter [1299+/-213 pmol per liter] P=0.004 for the comparison with base line, and 296+/-60 pg per milliliter [1616+/-327 pmol per liter], P=0.004, respectively). The patients' plasma norepinephrine responses were also reduced during sleep, whereas their plasma cortisol concentrations did not increase and their plasma growth hormone concentrations increased slightly. The patterns of counterregulatory-hormone responses in the normal subjects were similar.

CONCLUSIONS

Sleep impairs counterregulatory-hormone responses to hypoglycemia in patients with diabetes and normal subjects.

What makes a coronary myocardial bridge symptomatic?

The clinical significance of coronary myocardial bridging has been debated and different interventional strategies proposed. We discuss the case of a patient who presented with the recent onset of symptoms of exertional chest pain, diaphoresis, and electrocardiographic signs of acute anterior myocardial wall ischemia. Cardiac catheterization demonstrated a segmental high-grade narrowing of the mid left anterior descending coronary artery during systole consistent with bridging. Intravenous fluid resuscitation and calcium channel blockade resulted in normalization of his electrocardiogram and complete resolution of his anginal symptoms and coronary angiographic systolic narrowing.

Optical oxygen sensor instrumentation based on the detection of luminescence lifetime

Optical oxygen sensors are mainly based on the principle of luminescence quenching. In contrast to arready existing intensity-based systems, the measurement of the luminescence lifetime provides certain advantages, such as insensitivity to photobleaching or leaching of the dye, or changes in the intensity of excitation light. This facilitates the use of simple optical systems or optical fibres. A new family of oxygen-sensitive dyes, the porphyrin-ketones, has been introduced, which exhibits favorable spectral properties and decay times in the order of tens and hundreds of microseconds. This allows the use of simple optoelectronic circuitry and low-cost processing electronics. An optical oxygen sensor module has been developed with the dimensions of only 120 x 60 x 30 mm. The prototype is based on the measurement of the decay time of the luminophore by measuring the phase shift between the square-wave excitation and the detected square-wave of the emission coming from the sensor. The instrument is based on semiconductor devices (light-emitting diodes, photodiodes) and may be used for the detection of oxygen in gaseous or liquid samples. The measurement range of the device is from 0 to 200 hPa oxygen partial pressure with a resolution of < 1 hPa over the whole measurement range. The overall measurement accuracy of < +/- 1 hPa has been obtained for periods of 24 h of continuous measurement in a thermostatted environment. The sensor response times t90 are typically < 1 s for gases and 0.5 to 5 min for liquid samples.

Thyroid function in a population of children with attention deficit hyperactivity disorder

OBJECTIVE

To determine the prevalence of thyroid hormone abnormalities and generalized resistance to thyroid hormone in a population of children with attention deficit hyperactivity disorder (ADHD) as compared to reference ranges determined from a control population and hence to determine if routine thyroid hormone screening in children with non-familial ADHD is indicated.

METHOD

Children attending the State Child Development Centre in Perth, Western Australia with ADHD, as defined by the Diagnostic and Statistical Manual of Mental Disorders (fourth edition) provided the study population. The control population consisted of 353 normal children with a history of allergy in whom radioallergosorbent (RAST) testing was being performed.

RESULTS

The prevalence of thyroid hormone abnormalities in the study population was 2.3% (95% CI 0.6%, 5.7%). There were no cases of generalized resistance to thyroid hormone. The prevalence of thyroid hormone abnormalities in the general population of children and adolescents has been reported to vary between 1 and 3.7%.

CONCLUSION

Routine thyroid hormone screening is not indicated in children with non-familial ADHD.

'Saturday flit, short sit'--a strong influence of a superstition on the timing of hospital discharges?

'Saturday Flit, Short Sit' is a phrase recognised by 58% of our patient population. The superstition implies that leaving hospital on a Saturday is bad luck and will mean early re-admission to hospital. 13.7% of all patients interviewed would refuse to go home on a Saturday and 40% of doctors would allow postponement of discharge because of the patients superstition.

The impact of antenatal screening for Down syndrome in Western Australia: 1980-1994

Since the early 1970s, women in Western Australia have been screened for fetal Down syndrome risk on the basis of maternal age. Women 35 years of age or more at delivery, were offered fetal karyotyping with genetic diagnostic testing via amniocentesis or chorionic villus sampling. An increase in the prevalence of Down syndrome of 3.9% per year (95% confidence interval: 1.8-6.0%) was observed between 1980 and 1994, almost all of which was accounted for by increased maternal age. In 1991, a maternal serum screening (MSS) programme for Down syndrome was first implemented in Western Australia and has since evolved in 6 separate laboratories providing Down risk assessment in 1994. The gradual introduction of MSS programmes had little discernible impact until 1994, when 38% of Down syndrome fetuses were ascertained as a result of increased-risk MSS tests and the birth prevalence of Down syndrome decreased significantly. In this report, we review antenatal screening programmes and their impact on the birth prevalence of Down syndrome in Western Australia.

Serum progesterone and human chorionic gonadotrophin measurements in the evaluation of ectopic pregnancy

We evaluated the clinical usefulness of measuring the serum concentrations of human chorionic gonadotrophin (HCG) and progesterone to distinguish between early viable and nonviable pregnancies. We investigated 110 women with clinical symptoms of abnormal pregnancy. A single HCG measurement did not clearly distinguish between ectopic and failing intrauterine pregnancies; an HCG value below 3,000 IU/L, together with a serum progesterone below 40 nmol/L, predicted abnormal pregnancy outcome in 97% of women (positive predictive value: 91%; negative predictive value: 95%). Serum HCG value above 3,000 IU/L or progesterones above 40 nmol/L, discriminated between an ongoing pregnancy and an abnormal pregnancy in 87% women (positive predictive value: 95%; negative predictive value: 91%) and provided reassurance of an ongoing pregnancy. Our results suggest that a combination of serum progesterone and HCG measurements provide clinically useful biochemical information which enhances the prediction of pregnancy outcome.

New instrumentation for optical measuring of oxygen in gas or dissolved in liquids

The optical oxygen sensor is a novel device for the determination of oxygen in gases or dissolved in liquids. It is based on the measurement principle of fluorescence quenching, which is completely different from that of polarographic oxygen sensors (today the most widespread devices of oxygen detection). The new instrument offers features and advantages, which render it not only a realistic alternative, but, for specific applications, make it superior to existing electrochemical methods. The system is based on low-cost semiconductor devices (light-emitting diodes, photodiodes, low-cost analogue and digital components) and new LED-compatible oxygen-sensitive membranes. The flow cell of the instrument may be thermostatted and the sensor can be calibrated by a simple two-point calibration procedure. The optical oxygen sensor is particularly suitable for measuring dissolved oxygen in respirometry, since no oxygen is consumed by the device and the signal is independent of sample flowrate or stirring speed. Typical fields of application are monitoring of oxygen in ground and drinking water, in process control in bioreactors and in breath gas and blood gas analysis.

Ambulatory paediatric surgery. The development of a day-care surgical centre

Ambulatory surgery has become an important component in the provision of surgical care. In 1987 a day-case surgical unit was established at Red Cross War Memorial Children's Hospital, Cape Town. Experience over a 6-year period (1987-1992) is reviewed in relation to the nature and total number of surgical procedures, pre-operative preparation, daily utilisation of the facility, postoperative care and complications. During this period 16,538 patients (mean age 3 years) were operated on in the unit. Nine surgical disciplines participated. Pre-operative assessment and preparation reduced the rate of cancellations on the day of surgery to less than 6%, with a 90% effective use of schedules operating time. Scarce nursing resources were also maximally utilised. Most procedures took less than 30 minutes and only 0.8% exceeded 1 hour. The average ward stay was 6 hours. No major complications were encountered and acceptance by patients and parents was excellent. Only 16 children who were not scheduled to do so needed to stay in hospital overnight. Recommendations to establish and improve day-stay surgical services are presented. It is concluded that a practical, efficient service can be established and that the authorities should be encouraged to expand appropriate facilities.

Optical triple sensor for measuring pH, oxygen and carbon dioxide

A triple sensor unit consisting of opto-chemical sensors for measurement of pH, oxygen and carbon dioxide in bioreactors is presented. The pH and the CO2 sensor are based on the color change of a pH-sensitive dye immobilized on a polymeric support. The resulting changes in absorption are monitored through optical fibers. The oxygen sensor is based on the quenching of the fluorescence of a metal-organic dye. All three sensors are fully LED compatible. The sensitive membranes consist of plastic films and can be stored and replaced conveniently. The sensors are sterilizable with hydrogen peroxide and ethanol. In addition, the pH sensor is steam sterilizable. Accuracy, resolution and reproducibility fulfill the requirements for use in biotechnological applications. Calibration procedures for each sensor are presented. The working principle and the performance of all three sensors are described, with particular emphasis given to their application in bioreactors.

Community activation and health promotion: identification of key organizations

PURPOSE

The purpose of this study is to identify the kinds of community organizations community leaders consider important for community health promotion efforts.

DESIGN

Key informants were identified by reputational sampling of organizations relevant to community health promotion. Key informants were asked to list organizations they considered important for community health promotion. Differences in identified organizations were compared across informants from seven urban, five suburban, seven rural, and three Native American communities, with significance evaluated by chi-square tests.

SETTING

This survey was conducted in 22 Western U.S. communities comprising the intervention and control communities of the Community Health Promotion Grants Program of the Henry J. Kaiser Family Foundation.

SUBJECTS

Key informants (N = 184) from community organizations, identified using a reputational sampling technique beginning with the health department, were interviewed by telephone.

MEASURES

Key informants listed organizations considered important for community health promotion in five areas: adolescent pregnancy, substance abuse, tobacco use, cancer, and cardiovascular disease.

RESULTS

Informants frequently identified the health department (mentioned by 78% of informants overall), schools (72%), governmental agencies (55%), hospitals (47%), health clinics (42%), churches (33%), and newspapers (32%) as important. Organizations more prominent in urban and suburban areas than in rural and Native American areas included television stations, health-related private nonprofit organizations, substance abuse treatment centers, and colleges. Private physicians were frequently identified in rural areas (44% of informants).(ABSTRACT TRUNCATED AT 250 WORDS)

Longitudinal assessment of changes in reproductive hormones during normal pregnancy

The concentrations of hormones measured in serum from maternal blood change dramatically during pregnancy. While the relative contributions of sex steroids shift from maternal ovaries and adrenals to the fetoplacental unit, other maternal tissues such as pituitary and liver respond to increasing concentrations of estrogen and secrete increasing amounts of prolactin and sex-hormone-binding globulin. To determine longitudinal changes in circulating maternal hormones, we collected blood from 60 women on three occasions during their pregnancies. We observed a 1.7-fold increase in testosterone concentration in serum; concentrations of sex-hormone-binding globulin in serum rose 5.6-fold. The major increase (6.8-fold) in estradiol in serum occurred within the first 16 weeks, followed by a further 4.8-fold increase by term. Mean concentrations of progesterone, 17-hydroxyprogesterone, and androstenedione in serum increased 11.9-, 3-, and 1.3-fold, respectively, whereas concentrations of dehydroepiandrosterone sulfate (DHEAS) fell by 50%. Mean serum prolactin concentrations increased 3.8-fold during the first trimester and by a similar amount during the final 24 weeks of pregnancy. We used these data, obtained from a cohort of women with uncomplicated pregnancies, to construct reference intervals for hormones in maternal serum.

Severe oxprenolol poisoning: the importance of glucagon infusion

We describe a case of severe oxprenolol poisoning (8 g overdose) where restoration of normal blood pressure depended critically on high-dose glucagon infusion after several bolus injections of glucagon had failed. We stress the importance of infusion delivery of glucagon in severe beta-blocker poisoning.

Experimentally induced ileal ulcers in rats. A model to study non-specific inflammatory bowel disease

A surgical technique was used to establish chronic intestinal ulcers in Sprague-Dawley rats. A 2-cm-long segment of the distal ileum was excised and left attached on the mesentery. The ileum was reanastomosed. The excluded ileal segment formed a 'cyst' of various sizes. Initially, the anastomoses healed well, but after 6-8 weeks para-anastomotic ulcers developed in more than 50% of the rats. Histopathology showed a chronic inflammatory reaction with a predominance of mononuclear cells and increased numbers of eosinophilic granulocytes. The surface of the ulcers was covered with bacteria. Penetrating ulcers with fistula formation occurred. It is concluded that this experimental model may be useful for time sequential studies of the development of chronic and ulcerative ileitis. It may also be used to study the effect of medical and surgical regimens for the treatment of non-specific chronic inflammatory bowel disease.

Delayed neck infection following anterior spine surgery

Pharyngoesophageal perforation and neck abscess formation is a rare complication of anterior cervical spine surgery. This complication usually manifests itself within the early postoperative period and is associated with soft tissue trauma at the time of surgery. We describe two cases of retropharyngeal abscesses and persistent pharyngocutaneous fistulae which occurred in a delayed fashion several months after cervical spine surgery. The etiology, diagnosis, and treatment of this problem is discussed with a review of the current literature.

The effects of ethane dimethane sulphonate (EDS) on bilaterally cryptorchid rat testes

A single dose of ethane dimethane sulphonate (EDS) given to adult male rats has a specific destructive effects on Leydig cells, which are removed from the intertubular area by macrophages. This is associated with a decrease in testosterone (T) and a rise in serum FSH and LH for 21-28 days after EDS. Recovery of Leydig cells occurs from connective tissue precursors. This study uses the bilaterally cryptorchid rat to investigate the influence of local factors from the seminiferous tubules on the restoration of Leydig cell morphology and function. Morphometric data of intertubular tissue, hCG binding, serum T, FSH and LH levels all indicate that the Leydig cell population in cryptorchid testes is more rapidly restored from connective tissue cells when compared to the normal situation. The precise mechanism for this faster recovery will require further study.

Localization of nucleolar phosphoproteins B23 and C23 during mitosis

Nucleolar phosphoproteins B23 and C23 were simultaneously localized in unsynchronized male rat-kangaroo PtK2 cells during mitosis using a mouse monoclonal antibody against protein B23 and a rabbit antibody against protein C23. The distribution of proteins B23 and C23 during mitosis was compared with the distribution of the silver staining protein. During interphase, proteins B23 and C23 were both localized to the nucleolus. As the nucleolus disappeared in prophase, the distribution of protein B23 became nucleoplasmic, whereas most of protein C23 remained associated with the disappearing nucleolus. Throughout metaphase and anaphase protein B23 was found associated with the chromosomes, whereas protein C23 seemed to disappear. When the nucleolus reformed during telophase, protein C23 appeared first in 'prenucleolar bodies' and then in the nucleolus, whereas protein B23 did not appear in the nucleolus until late telophase or early G1 phase. Silver staining during mitosis closely paralleled the distribution of protein C23, supporting previous conclusions that protein C23 is a silver staining nucleolus organizer region (NOR) protein [19, 20].

Effects of 12-O-tetradecanoylphorbol-13-acetate and mezerein on gamma radiation-induced DNA repair in resting bovine lymphocytes

The present study was undertaken to determine the effect of the potent tumor promoter, 12-O-tetradecanoylphorbol-13-acetate (TPA) on gamma radiation-induced DNA repair in resting (Go) lymphocytes. Mezerein, a non-promoter but a co-mitogen in lymphocytes, was used as a control agent. It was previously proposed that a possible mechanism for the action of tumor promoters was through the inhibition of DNA repair processes. Our results indicate that TPA does not inhibit DNA repair following gamma irradiation of Go lymphocytes. These data support the hypothesis that the tumor promoting ability of TPA is not a result of impaired repair of potentially mutagenic lesions in DNA.