Referral patterns and genetic testing outcomes in a contemporary hereditary renal cancer clinic

OBJECTIVES

Multidisciplinary hereditary tumor clinics are a collaborative format to identify and treat patients with genetic cancer predispositions. The hereditary renal cancer clinic at Indiana University is comprised of a urologic oncologist, medical oncologist, clinical geneticist, and genetic counselor. The clinic holds regular tumor board meetings, where patient histories, pedigrees, imaging, pathology, and management plans are collectively reviewed and discussed. Here we report the contemporary experience for our hereditary renal cancer clinic, with description and analysis of referral patterns, patient profiles, and genetic testing outcomes.

MATERIALS AND METHODS

A retrospective review of an IRB-approved, prospectively maintained database of patients seen in the hereditary renal cancer clinic was performed. Patient characteristics, genetic testing results, and disease characteristics were reported and analyzed.

RESULTS

A total of 142 patients seen in clinics from January 2018 to June 2023 were included. Patient's median age was between 40 and 49 years old, and 88.7% were Caucasian. The most common reasons for referral were early-onset renal tumors (40%), known hereditary renal cancer syndrome (29%), and hereditary renal cancer syndrome screening (13%). Of those with a tissue diagnosis of renal cell carcinoma, 46.2% were clear cell subtype. The presence of nonrenal syndromic features concerning for hereditary renal tumor syndrome was predictive of pathogenic mutation identification (OR 13.45, P < 0.0001). Patient race and presence of multifocal tumors were not predictive of pathogenic mutation identification. When restricting analysis to patients with an established renal malignancy, high-grade tumor histology was predictive of a pathogenic mutation (OR 8.17, P = 0.012), though higher pathologic stage and nonclear cell histology were not. Referral for early-onset renal tumor (age < 45 years) predicted lower likelihood of pathogenic mutations (OR 0.10, P = 0.0002). FH gene mutations were the most commonly identified pathogenic mutations. Genetic testing of family members (cascade testing) was recommended to 9 patients seen in clinic; a pathogenic mutation was subsequently identified in all but one of these families.

CONCLUSIONS

These findings are useful for referring physicians and patients in determining patient referral to hereditary cancer clinics, and for counseling patients undergoing genetic testing. Data from non-Caucasian patients and evolving implications of variants of unclear significance (VUS) may represent future research directions for hereditary renal cancer clinics.

Impact of variant histology on upstaging and survival in patients with nonmuscle invasive bladder cancer undergoing radical cystectomy

INTRODUCTION

Variant histology (VH) of urothelial carcinoma is uncommon and frequently presents at the muscle-invasive stage. VH is considering a significant risk factor for progression among patients with nonmuscle invasive bladder cancer (NMIBC). While there is some debate, expert opinion is generally that upfront radical cystectomy (RC) should be consider for these patients. Limited data exists to support this position. In this study, we sought to examine the rate of upstaging and overall survival for patients with VH NMIBC against patients with pure urothelial NMIBC who underwent RC, to help clarify the optimal treatment strategy for these patients.

METHODS

The institutional REDCap database was utilized to identify all patients with T1 and Ta bladder cancer that underwent RC over the study period (2004-2022). Matched-pair analysis was performed between patients with VH and pure urothelial NMIBC; 42 pairs were matched on prior intravesical therapy, presence of muscularis propria on transurethral resection of bladder tumor (TURBT), any carcinoma in situ presence on prior TURBTs, and final tumor staging on TURBT. The primary outcomes of interest were pathologic tumor upstaging rate at RC and overall survival. Secondary outcomes of interest included association of demographic or pretreatment variables with upstaging, and upstaging rates for specific variant histologies.

RESULTS

Patients with VH NMIBC undergoing RC were upstaged at a significantly higher rate than a matched cohort of patients with pure urothelial NMIBC (73.8% vs. 52.4%, P = 0.0244) and among those upstaged, had significantly higher rates of pT3 to pT4 (54.7% vs. 23.8%, P = 0.0088). Rate of node positivity at RC for VH NMIBC was also higher compared to pure urothelial NMIBC (40.5% vs. 21.4%, P = 0.0389). Among histologic variants, patients with plasmacytoid and sarcomatoid subtypes demonstrated the highest rates of upstaging; differences were not statistically significant. The overall median survival was 28.4 months for patients with VH after RC compared to 155.1 months for patients with pure urothelial NMIBC (P = 0.009).

CONCLUSION

Patients with VH NMIBC undergoing RC are at significantly higher risk of upstaging at RC when compared to patients with pure urothelial NMIBC and have worse overall survival. While this study supports the concept of an aggressive treatment approach for patients with VH NMIBC, improvements in understanding of the disease are necessary to improve outcomes.

Phenotypic heterogeneity in persisters: a novel 'hunker' theory of persistence

Persistence has been linked to treatment failure since its discovery over 70 years ago and understanding formation, nature and survival of this key antibiotic refractory subpopulation is crucial to enhancing treatment success and combatting the threat of antimicrobial resistance (AMR). The term 'persistence' is often used interchangeably with other terms such as tolerance or dormancy. In this review we focus on 'antibiotic persistence' which we broadly define as a feature of a subpopulation of bacterial cells that possesses the non-heritable character of surviving exposure to one or more antibiotics; and persisters as cells that possess this characteristic. We discuss novel molecular mechanisms involved in persister cell formation, as well as environmental factors which can contribute to increased antibiotic persistence in vivo, highlighting recent developments advanced by single-cell studies. We also aim to provide a comprehensive model of persistence, the 'hunker' theory which is grounded in intrinsic heterogeneity of bacterial populations and a myriad of 'hunkering down' mechanisms which can contribute to antibiotic survival of the persister subpopulation. Finally, we discuss antibiotic persistence as a 'stepping-stone' to AMR and stress the urgent need to develop effective anti-persister treatment regimes to treat this highly clinically relevant bacterial sub-population.

Shigella sonnei Outbreak Investigation During a Municipal Water Crisis-Genesee and Saginaw Counties, Michigan, 2016

Objectives. To investigate a shigellosis outbreak in Genesee County, Michigan (including the City of Flint), and Saginaw County, Michigan, in 2016 and address community concerns about the role of the Flint water system.Methods. We met frequently with community members to understand concerns and develop the investigation. We surveyed households affected by the outbreak, analyzed Shigella isolate data, examined the geospatial distribution of cases, and reviewed available water quality data.Results. We surveyed 83 households containing 158 cases; median age was 10 years. Index case-patients from 55 of 83 households (66%) reported contact with a person outside their household who wore diapers or who had diarrhea in the week before becoming ill; results were similar regardless of household drinking water source. Genomic diversity was not consistent with a point source. In Flint, no space-time clustering was identified, and average free chlorine residual values remained above recommended levels throughout the outbreak period.Conclusions. The outbreak was most likely caused by person-to-person contact and not by the Flint water system. Consistent community engagement was essential to the design and implementation of the investigation.

The epidemic of methylisothiazolinone contact allergy in Europe: follow-up on changing exposures

BACKGROUND

Methylisothiazolinone (MI) has caused an unprecedented epidemic of contact allergy in Europe and elsewhere. Subsequently, regulatory action has been taken, at least in Europe, aiming at reducing risk of MI sensitization.

OBJECTIVE

To follow-up on the prevalence of contact allergy to MI in consecutively patch tested patients and assess the spectrum of products containing MI or methylchloroisothiazolinone (MCI)/MI in patients positive to MI which elicited current allergic contact dermatitis.

METHODS

A cross-sectional survey was performed in 2016 and 2017, including all adult patients patch tested with the baseline series (including MI 0.2% aq.) between 1 May and 31 October at 14 centres in 11 European countries. Patients with positive reactions (+ to +++) to MI were further examined regarding history, clinical characteristics and eliciting products, which were categorized into 34 types and 4 classes (leave-on, rinse-off, household, occupational). The results were compared with the reference year 2015.

RESULTS

A total of 317 patients, n = 202 of 4278 tested in 2016 (4.72%) and n = 115 of 3879 tested in 2017 (2.96%), had positive reactions to MI; the previous result from 2015 was 5.97% (P < 0.0001). The share of currently relevant contact allergy among all positive reactions declined significantly as well (P = 0.0032). Concerning product classes, a relative decline of leave-on and a relative increase of rinse-off and household products was noted.

CONCLUSION

The prevalence of MI contact allergy decreased by 50% from 2015 to 2017. As a consequence of regulation, the share of cosmetics products (leave-on in particular) eliciting allergic contact dermatitis is decreasing. The chosen method of analysing causative products in sensitized patients has proven useful to monitor effects of intervention.

Maternal and perinatal outcomes in pregnant women with suspected Ebola virus disease in Sierra Leone, 2014

OBJECTIVE

To describe maternal and perinatal outcomes among pregnant women with suspected Ebola virus disease (EVD) in Sierra Leone.

METHODS

Observational investigation of maternal and perinatal outcomes among pregnant women with suspected EVD from five districts in Sierra Leone from June to December 2014. Suspected cases were ill pregnant women with symptoms suggestive of EVD or relevant exposures who were tested for EVD. Case frequencies and odds ratios were calculated to compare patient characteristics and outcomes by EVD status.

RESULTS

There were 192 suspected cases: 67 (34.9%) EVD-positive, 118 (61.5%) EVD-negative, and 7 (3.6%) EVD status unknown. Women with EVD had increased odds of death (OR 10.22; 95% CI, 4.87-21.46) and spontaneous abortion (OR 4.93; 95% CI, 1.79-13.55) compared with those without EVD. Women without EVD had a high frequency of death (30.2%) and stillbirths (65.9%). One of 14 neonates born following EVD-negative and five of six neonates born following EVD-positive pregnancies died.

CONCLUSION

EVD-positive and EVD-negative women with suspected EVD had poor outcomes, highlighting the need for increased attention and resources focused on maternal and perinatal health during an urgent public health response. Capturing pregnancy status in nationwide surveillance of EVD can help improve understanding of disease burden and design effective interventions.

Vaccine shot-limiting: Estimating the prevalence, indicators, and impact on vaccination status - Michigan, 2012

BACKGROUND

Concerns regarding vaccine safety and pain have prompted certain parents to limit the number of shots their child receives per visit. We estimated the prevalence of shot-limited children in Michigan, described their characteristics, assessed whether shot-limited children were up-to-date on recommended vaccinations, and investigated possible intervention points for vaccination education.

METHODS

We analyzed vaccination registry and birth record data of children born in Michigan during 2012 who had ⩾2 vaccination visits, with ⩾1 visits after age 5months. Shot-limited was defined as receiving ⩽2 shots at all visits through age 24months. Nonlimited children received >2 shots at ⩾1 visits. Up-to-date vaccination was based on receipt of a seven-vaccine series and was determined at ages 24months and 35months. Risk ratios (RR) were calculated using risk regression.

RESULTS

Of 101,443 children, a total of 2,967 (3%) children were shot-limited. Mothers of shot-limited children were more likely to be white (RR: 1.2; 95% confidence interval [CI]: 1.2-1.2), college graduate (RR: 1.9; 95% CI: 1.9-2.0), and married (RR: 1.5; 95% CI: 1.5-1.5). Compared with nonlimited children, shot-limited children were more likely to be born in a nonhospital setting (RR: 11.7; 95% CI: 9.4-14.6) and have a midwife attendant (RR: 1.9; 95% CI: 1.7-2.1). Shot-limited children were less likely to be up-to-date on recommended vaccinations (RR: 0.2; 95% CI: 0.2-0.3); this association was stronger for those with a midwife birth attendant (RR: 0.1; 95% CI: 0.1-0.2) rather than a medical doctor (RR: 0.3; 95% CI: 0.2-0.3).

CONCLUSIONS

Shot-limited children are less likely to be up-to-date on vaccinations, possibly leading to increased risk for vaccine-preventable diseases. This association was stronger for those with a midwife birth attendant. This analysis should prompt targeted education, such as to midwives, concerning risks associated with shot-limiting behavior.

Notes from the Field: Cluster of Lymphogranuloma Venereum Cases Among Men Who Have Sex with Men - Michigan, August 2015-April 2016

Lymphogranuloma venereum (LGV) is a sexually transmitted disease (STD) caused by infection with invasive Chlamydia trachomatis serovars L1-L3 (1). LGV is characterized by inguinal and/or femoral lymphadenopathy, typically following a transient, self-limited genital ulcer or papule that might go unnoticed. Rectal infection can result in proctocolitis that can present with mucoid and/or hemorrhagic rectal discharge, anal pain, constipation, fever, and tenesmus, and signs of granulomas and/or ulcerations on anoscopy (1,2). LGV can be an invasive, systemic infection, and if it is not treated early, LGV proctocolitis can lead to chronic colorectal fistulas and strictures (2). In Europe, outbreaks of LGV have been reported among men who have sex with men (MSM), often in association with human immunodeficiency virus (HIV) coinfection (3-5). The prevalence of LGV in the United States is unknown (1), because diagnostic tests to differentiate LGV from non-LGV Chlamydia trachomatis are not widely available (6), and providers might not know that they should report cases that are presumptively treated.

Nosocomial transmission of Ebola virus disease on pediatric and maternity wards: Bombali and Tonkolili, Sierra Leone, 2014

BACKGROUND

In the largest Ebola virus disease (EVD) outbreak in history, nosocomial transmission of EVD increased spread of the disease. We report on 2 instances in Sierra Leone where patients unknowingly infected with EVD were admitted to a general hospital ward (1 pediatric ward and 1 maternity ward), exposing health care workers, caregivers, and other patients to EVD. Both patients died on the general wards, and were later confirmed as being infected with EVD. We initiated contact tracing and assessed risk factors for secondary infections to guide containment recommendations.

METHODS

We reviewed medical records to establish the index patients' symptom onset. Health care workers, patients, and caregivers were interviewed to determine exposures and personal protective equipment (PPE) use. Contacts were monitored daily for EVD symptoms. Those who experienced EVD symptoms were isolated and tested.

RESULTS

Eighty-two contacts were identified: 64 health care workers, 7 caregivers, 4 patients, 4 newborns, and 3 children of patients. Seven contacts became symptomatic and tested positive for EVD: 2 health care workers (1 nurse and 1 hospital cleaner), 2 caregivers, 2 newborns, and 1 patient. The infected nurse placed an intravenous catheter in the pediatric index patient with only short gloves PPE and the hospital cleaner cleaned the operating room of the maternity ward index patient wearing short gloves PPE. The maternity ward index patient's caregiver and newborn were exposed to her body fluids. The infected patient and her newborn shared the ward and latrine with the maternity ward index patient. Hospital staff members did not use adequate PPE. Caregivers were not offered PPE.

CONCLUSIONS

Delayed recognition of EVD and inadequate PPE likely led to exposures and secondary infections. Earlier recognition of EVD and adequate PPE might have reduced direct contact with body fluids. Limiting nonhealth-care worker contact, improving access to PPE, and enhancing screening methods for pregnant women, children, and inpatients may help decrease EVD transmission in general health care settings.

MAVEN observations of the response of Mars to an interplanetary coronal mass ejection

Coupling between the lower and upper atmosphere, combined with loss of gas from the upper atmosphere to space, likely contributed to the thin, cold, dry atmosphere of modern Mars. To help understand ongoing ion loss to space, the Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft made comprehensive measurements of the Mars upper atmosphere, ionosphere, and interactions with the Sun and solar wind during an interplanetary coronal mass ejection impact in March 2015. Responses include changes in the bow shock and magnetosheath, formation of widespread diffuse aurora, and enhancement of pick-up ions. Observations and models both show an enhancement in escape rate of ions to space during the event. Ion loss during solar events early in Mars history may have been a major contributor to the long-term evolution of the Mars atmosphere.

Early MAVEN Deep Dip campaign reveals thermosphere and ionosphere variability

The Mars Atmosphere and Volatile Evolution (MAVEN) mission, during the second of its Deep Dip campaigns, made comprehensive measurements of martian thermosphere and ionosphere composition, structure, and variability at altitudes down to ~130 kilometers in the subsolar region. This altitude range contains the diffusively separated upper atmosphere just above the well-mixed atmosphere, the layer of peak extreme ultraviolet heating and primary reservoir for atmospheric escape. In situ measurements of the upper atmosphere reveal previously unmeasured populations of neutral and charged particles, the homopause altitude at approximately 130 kilometers, and an unexpected level of variability both on an orbit-to-orbit basis and within individual orbits. These observations help constrain volatile escape processes controlled by thermosphere and ionosphere structure and variability.

Vaccination with tetanus, diphtheria, and acellular pertussis vaccine of pregnant women enrolled in Medicaid--Michigan, 2011-2013

In October 2011, the Advisory Committee on Immunization Practices (ACIP) first recommended the routine administration of a tetanus, diphtheria, and acellular pertussis vaccine (Tdap) during pregnancy as a strategy to protect infants from pertussis (also known as whooping cough). This recommendation applied to women previously unvaccinated with Tdap and specified the optimal vaccination time as late second or third trimester (after 20 weeks' gestation). By vaccinating pregnant women, infants, who are at highest risk for mortality and morbidity from pertussis, gain passive immunity from maternal antibodies transferred to them in utero. Since this recommendation was made, little has been published on the percentage of women receiving Tdap during pregnancy. In Michigan, Medicaid pays for costs of pregnancy for approximately 40% of births. Infants enrolled in Medicaid are a particularly vulnerable population; in Michigan, their all-cause mortality is higher than that of privately insured infants. To assess vaccination coverage among pregnant women enrolled in a publicly funded insurance program in Michigan, Medicaid administrative claims data and statewide immunization information system data for mothers of infants born during November 2011-February 2013 were analyzed. This report describes the results of that analysis, which indicated that only 14.3% of these women received Tdap during pregnancy, with rates highest (17.6%) among non-Hispanic, non-Arab whites and lowest (6.8%) among Arab women. Vaccination was related to maternal age and gestational age at birth, but not to adequacy of prenatal care. In 2013, recognizing the importance of Tdap for every pregnancy, ACIP revised its guidelines to include a Tdap dose during every pregnancy. Ensuring that all infants receive the protection against pertussis afforded by maternal vaccination will require enhanced efforts to vaccinate pregnant women.

Clinical findings for fungal infections caused by methylprednisolone injections

BACKGROUND

Since September 18, 2012, public health officials have been investigating a large outbreak of fungal meningitis and other infections in patients who received epidural, paraspinal, or joint injections with contaminated lots of methylprednisolone acetate. Little is known about infections caused by Exserohilum rostratum, the predominant outbreak-associated pathogen. We describe the early clinical course of outbreak-associated infections.

METHODS

We reviewed medical records for outbreak cases reported to the Centers for Disease Control and Prevention before November 19, 2012, from the six states with the most reported cases (Florida, Indiana, Michigan, New Jersey, Tennessee, and Virginia). Polymerase-chain-reaction assays and immunohistochemical testing were performed on clinical isolates and tissue specimens for pathogen identification.

RESULTS

Of 328 patients without peripheral-joint infection who were included in this investigation, 265 (81%) had central nervous system (CNS) infection and 63 (19%) had non-CNS infections only. Laboratory evidence of E. rostratum was found in 96 of 268 patients (36%) for whom samples were available. Among patients with CNS infections, strokes were associated with an increased severity of abnormalities in cerebrospinal fluid (P<0.001). Non-CNS infections were more frequent later in the course of the outbreak (median interval from last injection to diagnosis, 39 days for epidural abscess and 21 days for stroke; P<0.001), and such infections developed in patients with and in those without meningitis.

CONCLUSIONS

The initial clinical findings from this outbreak suggest that fungal infections caused by epidural and paraspinal injection of a contaminated glucocorticoid product can result in a broad spectrum of clinical disease, reflecting possible variations in the pathogenic mechanism and in host and exposure risk factors. (Funded by the Centers for Disease Control and Prevention.).

Design of double-walled carbon nanotubes for biomedical applications

Double-walled carbon nanotubes (DWNTs) prepared by catalytic chemical vapour deposition were functionalized in such a way that they were optimally designed as a nano-vector for the delivery of small interfering RNA (siRNA), which is of great interest for biomedical research and drug development. DWNTs were initially oxidized and coated with a polypeptide (Poly(Lys:Phe)), which was then conjugated to thiol-modified siRNA using a heterobifunctional cross-linker. The obtained oxDWNT-siRNA was characterized by Raman spectroscopy inside and outside a biological environment (mammalian cells). Uptake of the custom-designed nanotubes was not associated with detectable biochemical perturbations in cultured cells, but transfection of cells with DWNTs loaded with siRNA targeting the green fluorescent protein (GFP) gene, serving as a model system, as well as with therapeutic siRNA targeting the survivin gene, led to a significant gene silencing effect, and in the latter case a resulting apoptotic effect in cancer cells.

Behavior of poly(glycerol sebacate) plugs in chronic tympanic membrane perforations

The tympanic membrane (TM), separating the external and middle ear, consists of fibrous connective tissue sandwiched between epithelial layers. To treat chronic ear infections, tympanostomy drainage tubes are placed in surgically created holes in TMs which can become chronic perforations upon extrusion. Perforations are repaired using a variety of techniques, but are limited by morbidity, unsatisfactory closure rates, or minimal regeneration of the connective tissue. A more effective, minimally-invasive therapy is necessary to enhance the perforation closure rate. Current research utilizing decellularized or alignate materials moderately enhance closure but the native TM architecture is not restored. Poly(glycerol sebacate) (PGS) is a biocompatible elastomer which supports cell migration and enzymatically degrades in contact with vascularized tissue. PGS spool-shaped plugs were manufactured using a novel process. Using minimally invasive procedures, these elastomeric plugs were inserted into chronic chinchilla TM perforations. As previously reported, effective perforation closure occurred as both flange surfaces were covered by confluent cell layers; >90% of perforations were closed at 6-week postimplantation. This unique in vivo environment has little vascularized tissue. Consequently, PGS degradation was minimal over 16-week implantation, hindering regeneration of the TM fibrous connective tissue. PGS degradation must be enhanced to promote complete TM regeneration.

AFM imaging of functionalized carbon nanotubes on biological membranes

Multifunctional carbon nanotubes are promising for biomedical applications as their nano-size, together with their physical stability, gives access into the cell and various cellular compartments including the nucleus. However, the direct and label-free detection of carbon nanotube uptake into cells is a challenging task. The atomic force microscope (AFM) is capable of resolving details of cellular surfaces at the nanometer scale and thus allows following of the docking of carbon nanotubes to biological membranes. Here we present topographical AFM images of non-covalently functionalized single walled (SWNT) and double walled carbon nanotubes (DWNT) immobilized on different biological membranes, such as plasma membranes and nuclear envelopes, as well as on a monolayer of avidin molecules. We were able to visualize DWNT on the nuclear membrane while at the same time resolving individual nuclear pore complexes. Furthermore, we succeeded in localizing individual SWNT at the border of incubated cells and in identifying bundles of DWNT on cell surfaces by AFM imaging.

Mycobacterium bovis BCG as a delivery system for the RAP-1 antigen from Babesia bovis

Babesia bovis is the causative agent of babesiosis, a tick-borne disease that is a major cause of loss to livestock production in Latin America. Vaccination against Babesia species represents a major challenge against cattle morbidity and mortality in enzootic areas. The aim of this study was to evaluate the capacity of Bacille Calmette-Guerin (BCG) to deliver the rhoptry associated protein (RAP-1) antigen of B. bovis and to stimulate specific cellular and humoral immune responses in mice. Two of five mycobacterial expression vectors efficiently expressed the antigen. These constructs were subsequently studied in vivo following three immunization protocols. The construct with the greatest in vivo stability proved to be the one that induced the strongest immune responses. Our data support the hypothesis that specific T lymphocyte priming by rBCG can be employed as a component of a combined vaccine strategy to induce long-lasting humoral and cellular immune responsiveness towards B. bovis and encourage further work on the application of rBCG to the development of Babesia vaccines.

An interdisciplinary view of medical pluralism among Mexican-Americans

This article highlights the relationship between traditional, complementary, and alternative medicine (TCAM) and biomedicine, and the challenges this relationship poses to patients. Medical professionals tend to represent these systems dualistically - as mutually exclusive and in competition with one another. Patients, on the other hand, tend to make truly pluralistic health care decisions - moving freely between TCAM and biomedicine based on what they can access, what they can relate to, and what they believe works. Using their experience with Mexican immigrant and Mexican-American populations in Southwestern United States, the authors discuss strengths and weaknesses in both healthcare systems, and how medical dualism can be a significant barrier to effective healthcare. Recent literature on medical pluralism is discussed from the public health (i.e., community) and medical (i.e., provider) perspectives. These two disciplines are brought together in an attempt to deconstruct the notion that TCAM and biomedicine are diametrically opposed healthcare systems. Biomedically trained health care providers must understand, appreciate, and integrate into their practice how their patients make use of other healing practices and beliefs. Such integration is particularly essential when serving immigrant or minority populations as these groups are more likely to use a pluralistic approach in meeting their health needs.

Photopatch testing of 1155 patients: results of the U.K. multicentre photopatch study group

BACKGROUND

Photoallergic contact dermatitis can be difficult to diagnose if not appropriately investigated. Currently, the most common U.K. photoallergens appear to be sunscreen chemicals. The investigation of choice is photopatch testing (PPT), which is probably underused. In part, this is due to differences in methodology and results interpretation.

OBJECTIVES

To conduct PPT using a group of sunscreen chemicals, defined indications and a standardized methodology including interpretation and relevance of reactions in patients attending for investigation at 17 centres across the U.K., Ireland and the Netherlands.

METHODS

Patients (n = 1155) who fulfilled the inclusion criteria were investigated with PPT using sunscreen chemicals in addition to suspected topical products. Readings were taken at 24, 48 and 72 h following standardized ultraviolet A irradiation (5 J cm(-2)). The clinical relevance of any reaction was recorded.

RESULTS

Of the 1155, 130 had allergic reactions (11.3%). Of these, 51 had photoallergy (PA) (4.4%), 64 had contact allergy (CA) (5.5%), and 15 patients had combined PA and CA (1.3%). Multiple PA was seen in some. The most common photoallergen was benzophenone-3 (27 reactions; 21%). Most reactions (60%) were clinically relevant. The most common indication for testing in patients found to have PA was a history of reacting to a sunscreen (41%). The other 59% had an exposed-site dermatitis/skin problem or a photodermatosis. Some centres (n = 8) performed readings after the standard 48-h reading, and an extra 32 PA and 22 CA reactions were detected, which were not evident at 48 h. A new photoallergen (octyl triazone) was detected in two patients.

CONCLUSIONS

Sunscreen PA and CA are probably equally uncommon. Most reactions, of both reaction types, were relevant clinically. A large proportion of patients (59%) found to have PA was unaware of reacting to a sunscreen chemical, suggesting that PA should be considered as an explanation in any exposed-site dermatitis. Although this study focused on reactions at 48 h postirradiation, readings performed up to 96 h, while inconvenient, add value by detecting additional relevant responses. A previously unknown photoallergen was found, highlighting the need for awareness of novel photoallergens in the marketplace. A standardized PPT method not only encourages more use of this investigation, but also facilitates comparison of results between centres and so will improve our understanding of PA.

Compiling a molecular inventory for Mycobacterium bovis BCG at two growth rates: evidence for growth rate-mediated regulation of ribosome biosynthesis and lipid metabolism

An experimental system of Mycobacterium tuberculosis growth in a carbon-limited chemostat has been established by the use of Mycobacterium bovis BCG as a model organism. For this model, carbon-limited chemostats with low concentrations of glycerol were used to simulate possible growth rates during different stages of tuberculosis. A doubling time of 23 h (D = 0.03 h(-1)) was adopted to represent cells during the acute phase of infection, whereas a lower dilution rate equivalent to a doubling time of 69 h (D = 0.01 h(-1)) was used to model mycobacterial persistence. This chemostat model allowed the specific response of the mycobacterial cell to carbon limitation at different growth rates to be elucidated. The macromolecular (RNA, DNA, carbohydrate, and lipid) and elemental (C, H, and N) compositions of the biomass were determined for steady-state cultures, revealing that carbohydrates and lipids comprised more than half of the dry mass of the BCG cell, with only a quarter of the dry weight consisting of protein and RNA. Consistent with studies of other bacteria, the specific growth rate impacts on the macromolecular content of BCG and the proportions of lipid, RNA, and protein increased significantly with the growth rate. The correlation of RNA content with the growth rate indicates that ribosome production in carbon-limited M. bovis BCG cells is subject to growth rate-dependent control. The results also clearly show that the proportion of lipids in the mycobacterial cell is very sensitive to changes in the growth rate, probably reflecting changes in the amounts of storage lipids. Finally, this study demonstrates the utility of the chemostat model of mycobacterial growth for functional genomic, physiology, and systems biology studies.

Expression of the B-cell and T-cell epitopes of the rabies virus nucleoprotein in Mycobacterium bovis BCG and induction of an humoral response in mice

Expression vectors containing rabies virus nucleoprotein B-cell and T-cell epitopes in Mycobacterium bovis BCG were constructed. The epitopes were subcloned into the M. leprae 18-kDa gene to ensure correct presentation to the host immune system. Expression of the 18-kDa::B+T epitope fusion protein was driven by either the hsp60 promoter, which is constitutively activated at a high level in M. bovis BCG, or the 18-kDa promoter, which is strongly induced in vivo. Mice were immunised intra-peritoneally with the recombinant BCG cultures and compared to a control group vaccinated with the commercial rabies vaccine Rai-SAD. Both of the expression vectors elicited a higher antibody titre than that of the rabies vaccine, with the highest response shown by M. bovis BCG (pUP203), expression controlled by the 18-kDa promoter. Immunisation with M. bovis BCG (pUP202), expression controlled by the hsp60 promoter, resulted in a continuously increasing antibody titre up to 60 days post immunisation. The mice antibodies were also capable of recognising the whole rabies virus and not only the synthetic peptide epitopes.

Deletion of the putative antioxidant noxR1 does not alter the virulence of Mycobacterium tuberculosis H37Rv

SETTING

The cloned M. tuberculosis noxR1 gene has been shown to confer resistance to reactive nitrogen intermediates (RNI) and reactive oxygen intermediates (ROI) upon Escherichia coli and Mycobacterium smegmatis.

OBJECTIVE

To investigate the role of noxR1 in resistance to RNI and virulence of M. tuberculosis.

DESIGN

The noxR1 gene was deleted from M. bovis BCG and M. tuberculosis H37Rv by allelic exchange. The mutants were compared to wild type strains with respect to resistance to chemically generated RNI. The virulence of the M. tuberculosis mutant was investigated in a murine model of infection.

RESULTS

The NoxR1 mutants grew normally in Sautons and 7H9 broths. The BCG mutant demonstrated decreased resistance to in vitro generated RNI compared to the wild type. Resistance to RNI could be restored to the mutant by reintroduction of the noxR1 locus on a replicating plasmid. However, deletion of noxR1 from M. tuberculosis H37Rv did not result in decreased resistance to RNI nor a difference in growth and survival of the bacterium during murine infection.

CONCLUSION

The noxR1 gene locus in M. bovis BCG bestows ability to resist RNI generated in vitro. In M. tuberculosis H37Rv, however, noxR1 is either not involved in RNI resistance and virulence or is better compensated for by other mechanisms.

Antigen 43, the major phase-variable protein of the Escherichia coli outer membrane, can exist as a family of proteins encoded by multiple alleles

agn43 encodes a major phase-variable outer-membrane protein, antigen 43 (Ag43), involved in autoaggregation of Escherichia coli cells. The gene is present in single copy on the chromosome of E. coli K-12. In contrast, Southern hybridization and gene inactivation studies demonstrate that control producer strain E. coli ML308-225 possesses duplicate copies of agn43 (agn43A and agn43B). Construction and analyses of single and double knockout mutants clearly show that both alleles are capable of expressing antigen in a phase-variable manner, with observed differences in the ON<-->OFF switch frequencies appearing to favour expression of Ag43B under conditions of normal laboratory growth. Comparative analysis of agn43A and agn43B gene sequences revealed 98% identity at the nucleotide and predicted protein levels, with differences in the protein sequence of the surface-expressed alpha(43) subunit altering the surface probability of one of the predicted epitopes. Analysis of a panel of enteropathogenic E. coli strains by Southern hybridization using agn43-specific gene probes provided strong evidence for the presence of varying numbers of agn43 alleles within clinical isolates. Taken together, the results indicate the presence of a family of distinct Ag43 proteins encoded by multiple chromosomal alleles.

Intercellular IgA dermatosis (IgA pemphigus)--two cases illustrating the clinical heterogeneity of this disorder

IgA pemphigus is rare but may be underdiagnosed. We describe two cases, a 50-year-old female with a pustular eruption resembling subcorneal pustular dermatosis and a 55-year-old male with a pruritic vesiculopustular eruption simulating dermatitis herpetiformis. They illustrate the clinical heterogeneity of IgA pemphigus which is likely to reflect differences in autoantigens, analogous to pemphigus vulgaris and pemphigus foliaceus. There is now evidence that IgA pemphigus encompasses at least two subgroups: a subcorneal pustular dermatosis (SPD)-type, (see case 1) characterized by subcorneal pustules and autoantibodies to desmocollin 1; and intra-epidermal neutrophilic dermatosis (IEN)-type cases (see case 2) which show intra-epidermal pustules and in whom the autoantigen may be desmoglein 3, the pemphigus vulgaris antigen.

Stimulation of transposition of the Mycobacterium tuberculosis insertion sequence IS6110 by exposure to a microaerobic environment

The Mycobacterium tuberculosis-specific insertion sequence IS6110/986 has been widely used as a probe because of the multiple polymorphism observed among different strains. To investigate transposition of IS6110, a series of artificially constructed composite transposons containing IS6110 and a kanamycin resistance marker were constructed. The composite transposons were inserted into a conditionally replicating, thermosensitive, Escherichia coli-mycobacterial shuttle vector and introduced into M. smegmatis mc2155. Lawns of transformants were grown at the permissive temperature on kanamycin-supplemented agar and subsequently prevented from further growth by shifting to the non-permissive temperature. Under normal atmospheric conditions, kanamycin-resistant papillae appeared after only about 5-6 weeks of incubation. However, these events were not associated with transposon mobilization. In contrast, lawns that were exposed to a 48 h microaerobic shock generated kanamycin-resistant papillae after only 6-14 days. These events were generated by conservative transposition of the IS6110 composite transposon into the M. smegmatis chromosome, with loss of the shuttle vector. In common with other IS3 family elements, transposition of IS6110 is thought to be controlled by translational frameshifting. However, we were unable to detect any significant frameshifting within the putative frameshifting site of IS6110, and the level of frameshifting was not affected by microaerobic incubation. The finding that transposition of IS6110 is stimulated by incubation at reduced oxygen tensions may be relevant to transposition of IS6110 in M. tuberculosis harboured within TB lesions.

Lichenoid tissue reaction in porphyria cutanea tarda

We report a patient presenting with lichenoid plaques on exposed skin who had the metabolic features of porphyria cutanea tarda (PCT). Histology of lesional skin demonstrated a lichenoid inflammatory cell infiltrate in the upper dermis, while direct immunofluorescence revealed immunoreactive colloid bodies. Monochromator irradiation testing demonstrated photosensitivity in the visible spectrum consistent with porphyria. Solar-simulated irradiation induced a papular reaction with lichenoid histological changes. We propose that this atypical presentation of PCT may reflect a lichenoid tissue response to a porphyrin-mediated photochemical reaction.

A quantum mechanical model of adaptive mutation

The principle that mutations occur randomly with respect to the direction of evolutionary change has been challenged by the phenomenon of adaptive mutations. There is currently no entirely satisfactory theory to account for how a cell can selectively mutate certain genes in response to environmental signals. However, spontaneous mutations are initiated by quantum events such as the shift of a single proton (hydrogen atom) from one site to an adjacent one. We consider here the wave function describing the quantum state of the genome as being in a coherent linear superposition of states describing both the shifted and unshifted protons. Quantum coherence will be destroyed by the process of decoherence in which the quantum state of the genome becomes correlated (entangled) with its surroundings. Using a very simple model we estimate the decoherence times for protons within DNA and demonstrate that quantum coherence may be maintained for biological time-scales. Interaction of the coherent genome wave function with environments containing utilisable substrate will induce rapid decoherence and thereby destroy the superposition of mutant and non-mutant states. We show that this accelerated rate of decoherence may significantly increase the rate of production of the mutated state.

Global distribution of crustal magnetization discovered by the mars global surveyor MAG/ER experiment

Vector magnetic field observations of the martian crust were acquired by the Mars Global Surveyor (MGS) magnetic field experiment/electron reflectometer (MAG/ER) during the aerobraking and science phasing orbits, at altitudes between approximately 100 and 200 kilometers. Magnetic field sources of multiple scales, strength, and geometry were observed. There is a correlation between the location of the sources and the ancient cratered terrain of the martian highlands. The absence of crustal magnetism near large impact basins such as Hellas and Argyre implies cessation of internal dynamo action during the early Naochian epoch ( approximately 4 billion years ago). Sources with equivalent magnetic moments as large as 1.3 x 10(17) ampere-meter2 in the Terra Sirenum region contribute to the development of an asymmetrical, time-variable obstacle to solar wind flow around Mars.

Lunar surface magnetic fields and their interaction with the solar wind: results from lunar prospector

The magnetometer and electron reflectometer experiment on the Lunar Prospector spacecraft has obtained maps of lunar crustal magnetic fields and observed the interaction between the solar wind and regions of strong crustal magnetic fields at high selenographic latitude (30 degreesS to 80 degreesS) and low ( approximately 100 kilometers) altitude. Electron reflection maps of the regions antipodal to the Imbrium and Serenitatis impact basins, extending to 80 degreesS latitude, show that crustal magnetic fields fill most of the antipodal zones of those basins. This finding provides further evidence for the hypothesis that basin-forming impacts result in magnetization of the lunar crust at their antipodes. The crustal magnetic fields of the Imbrium antipode region are strong enough to deflect the solar wind and form a miniature (100 to several hundred kilometers across) magnetosphere, magnetosheath, and bow shock system.

DNA fingerprinting as an indicator of active transmission of multidrug-resistant tuberculosis in Poland

OBJECTIVES

To use genetic fingerprinting to investigate the epidemiology of tuberculosis (TB) caused by Mycobacterium tuberculosis in Poland, a country with a relatively high incidence of tuberculosis, to improve TB control.

DESIGN

One hundred M. tuberculosis isolates from 98 patients in the Institute of Tuberculosis and Lung Diseases in Warsaw from 1993 to 1995 and 85 isolates obtained from 50 patients in the Hospital of Lung Diseases in Lodz in 1996 were subjected to DNA restriction fragment length polymorphism (RFLP) analysis, using the insertion sequence IS6110 as a probe.

RESULTS

IS6110-associated banding patterns of the M. tuberculosis isolates originating from different localities varied considerably, but isolates from Lodz had a higher degree of similarity. Strains with identical RFLP types were identified in patients of the same family or patients living in the same area, indicating active transmission. Of strains isolated in Warsaw, 45% were resistant to at least one drug, and 35% were resistant to two or more drugs and were classified as multidrug-resistant (MDR). Some drug-resistant isolates were found to have identical banding patterns and originated from epidemiologically linked cases.

CONCLUSIONS

Active transmission of TB, including MDR TB, is occurring in Poland. Active measures must be taken to prevent the spread of drug-resistant TB in Poland and potentially, the rest of Europe.

Magnetic Field and Plasma Observations at Mars: Initial Results of the Mars Global Surveyor Mission

The magnetometer and electron reflectometer investigation (MAG/ER) on the Mars Global Surveyor spacecraft has obtained magnetic field and plasma observations throughout the near-Mars environment, from beyond the influence of Mars to just above the surface (at an altitude of approximately 100 kilometers). The solar wind interaction with Mars is in many ways similar to that at Venus and at an active comet, that is, primarily an ionospheric-atmospheric interaction. No significant planetary magnetic field of global scale has been detected to date (<2 x 10(21) Gauss-cubic centimeter), but here the discovery of multiple magnetic anomalies of small spatial scale in the crust of Mars is reported.

Magnetic Field and Plasma Observations at Mars: Initial Results of the Mars Global Surveyor Mission

The magnetometer and electron reflectometer investigation (MAG/ER) on the Mars Global Surveyor spacecraft has obtained magnetic field and plasma observations throughout the near-Mars environment, from beyond the influence of Mars to just above the surface (at an altitude of approximately 100 kilometers). The solar wind interaction with Mars is in many ways similar to that at Venus and at an active comet, that is, primarily an ionospheric-atmospheric interaction. No significant planetary magnetic field of global scale has been detected to date (<2 x 10(21) Gauss-cubic centimeter), but here the discovery of multiple magnetic anomalies of small spatial scale in the crust of Mars is reported.

Mycobacterial DNA not detected in liver sections from patients with primary biliary cirrhosis

BACKGROUND/AIMS

Recent studies in primary biliary cirrhosis have reported the detection of serum antibodies against Mycobacterium gordonae and of mycobacterial DNA in liver sections. The aim of this study was to investigate whether mycobacterial DNA is present in liver biopsy material in primary biliary cirrhosis.

METHODS

Archival liver biopsy specimens from 11 patients with primary biliary cirrhosis (10 female, mean age 52 years) and 11 patients with autoimmune hepatitis (10 female, mean age 53 years) were identified. Positive control tissue comprised five archival lymph node specimens from patients with tuberculous lymphadenopathy, three of which had stained positive on ZN staining, and also a liver biopsy specimen from a patient with tuberculous hepatitis (ZN positive). Fixed sections were deparaffinised and DNA was extracted by mechanical disruption with glass beads. DNA was purified by use of diatoms and lysis in guanidinium thiocyanate in a technique previously validated for archival DNA. Primers were directed to amplify a partial 16S ribosomal RNA gene yielding the species-specific character for mycobacteria, and also to amplify the constitutively-expressed human gene GAPDH.

RESULTS

The polymerase chain reaction was shown to be capable of detecting 1 fg of M. gordonae DNA in 'spiked' samples, equivalent to 1-5 bacterial cells. No mycobacterial DNA was detected in liver biopsy samples from either the primary biliary cirrhosis or autoimmune hepatitis groups. Of the tuberculous control sections, mycobacterial DNA was detected in four of five lymph nodes and the liver biopsy specimen. GAPDH amplification was detected in all tested samples from liver disease and tuberculous control samples.

CONCLUSION

These data do not support a role for mycobacteria in the aetiology of primary biliary cirrhosis.