Use of the QuantiFERON-TB Gold test to confirm latent tuberculosis infection in a Canadian tuberculosis clinic

SETTING

Capital Health Tuberculosis (TB) Clinic, Edmonton, Alberta, Canada.

OBJECTIVE

To analyze the QuantiFERON-TB Gold In-Tube test (QFT) results after implementation as a routine test for tuberculin skin test (TST) positive patients.

DESIGN

From November 2004 until January 2007, patients who were TST-positive and were eligible for preventive treatment based on Canadian guidelines, were offered a QFT.

RESULTS

Of 1446 TST-positive patients, only 566 (39.6%) were QFT-positive. Categorized by reason for TST testing, 43.1% of 304 contacts, 32.8% of 348 employment screens and 24.2% of 298 post secondary school screens were QFT-positive. In contrast, 59.7% of 290 immigration screens were QFT-positive. A multivariate analysis found that QFT positivity was associated with older age, larger TST size, high-incidence TB region of birth, history of TB and chest X-ray findings suggestive of previous TB.

CONCLUSION

Implementation of the QFT as a secondary test for latent TB infection (LTBI) can significantly reduce the number of patients given LTBI treatment in a low-incidence country such as Canada.

A comparative study on urinary purine derivative excretion of yak (Bos grunniens), cattle (Bos taurus), and crossbred (Bos taurus x Bos grunniens) in the Qinghai-Tibetan plateau, China

Two experiments were conducted to determine the urinary purine derivative (PD) excretion rates and to analyze potential variations in PD excretions between yak, Tibetan indigenous cattle, and their crossbreds under similar ecological environment, and to develop prediction equations based on PD excretion for estimating rumen microbial protein supply. Three Tibetan castrated male yaks, and similar numbers of indigenous cattle and their crossbreds, were used in a fasting trial followed by a feeding trial, using three 3 x 3 Latin squares (1 for each breedtype), to measure responses of PD excretion to different feeding levels. The results showed that i) daily endogenous PD excretion for yak, indigenous cattle, and their crossbreds was 134, 163, and 138 micromol/kg of BW(0.75) (P = 0.38), respectively; and ii) crossbreds have greater PD excretion rate per unit digestible OM intake than indigenous cattle (P = 0.03). However, there were no significant differences between yaks and the crossbreds (P = 0.24) or between yaks and the indigenous cattle (P = 0.25). The proportion of allantoin to total PD in urine ranged from 0.83 to 0.88, with the crossbreds having greater values compared with the 2 parents (P = 0.03). Daily glomerular filtration rate, calculated using endogenous creatinine as an internal marker, for the above animals was 3.85, 4.23, and 3.61 L/kg of BW(0.75), respectively, in fasting trial (P = 0.59). The alpine animals may develop special regulating mechanisms in the kidney in terms of glomerular filtration rate and PD excretion, which would help the animals in adapting to the harsh environment of the Qinghai-Tibetan plateau.

Multiple frequency modulation for low-light atom measurements in an optical cavity

We present a frequency modulation scheme to detect atoms dispersively in a high-finesse optical cavity at low-light levels with immunity to cavity length fluctuations. We use multiple cavity resonances to provide common mode noise rejection, keeping the high intensity carrier off-resonant from all cavity modes. The method has applications in atomic squeezed state generation and quantum metrology.

Habit reversal training for the itch-scratch cycle associated with pruritic skin conditions

Habit reversal therapy was originally developed by Azrin and Nunn in 1977 as a multicomponent treatment for nervous tics and habits. Their premise for clinical intervention was that an old habit can be broken by replacing it with a new, more desirable habit. Dermatology nurses trained in habit reversal therapy can enhance system management and quality of life for patients. Recommendations for the evaluation of habit reversal in patients with eczema and prurigo nodularis are made.

Neuregulin 1 (8p12) and childhood-onset schizophrenia: susceptibility haplotypes for diagnosis and brain developmental trajectories

Childhood-onset schizophrenia (COS), defined as onset of psychosis by the age of 12, is a rare and malignant form of the illness, which may have more salient genetic influence. Since the initial report of association between neuregulin 1 (NRG1) and schizophrenia in 2002, numerous independent replications have been reported. In the current study, we genotyped 56 markers (54 single-nucleotide polymorphisms (SNPs) and two microsatellites) spanning the NRG1 locus on 78 COS patients and their parents. We used family-based association analysis for both diagnostic (extended transmission disequilibrium test) and quantitative phenotypes (quantitative transmission disequilibrium test) and mixed-model regression. Most subjects had prospective anatomic brain magnetic resonance imaging (MRI) scans at 2-year intervals. Further, we genotyped a sample of 165 healthy controls in the MRI study to examine genetic risk effects on normal brain development. Individual markers showed overtransmission of alleles to affecteds (P=0.009-0.05). Further, several novel four-marker haplotypes demonstrated significant transmission distortion. There was no evidence of epistasis with SNPs in erbB4. The risk allele (0) at 420M9-1395 was associated with poorer premorbid social functioning. Further, possession of the risk allele was associated with different trajectories of change in lobar volumes. In the COS group, risk allele carriers had greater total gray and white matter volume in childhood and a steeper rate of subsequent decline in volume into adolescence. By contrast, in healthy children, possession of the risk allele was associated with different trajectories in gray matter only and was confined to frontotemporal regions, reflecting epistatic or other illness-specific effects mediating NRG1 influence on brain development in COS. This replication further documents the role of NRG1 in the abnormal brain development in schizophrenia. This is the first demonstration of a disease-specific pattern of gene action in schizophrenia.

Rapid sonic characterisation of sewer change and obstructions

This paper reports on the development of a low-cost, rapidly deployable sensor for surveying live sewers for blockages and structural failures. The anticipated cost is an order of magnitude lower than current techniques. The technology is based on acoustic normal model decomposition, The instrument emits short coded acoustic signals which are reflected from any sewer wall defect. The acoustic signals can be short Gaussian pulses or longer sinusoidal sweeps and pseudo-random noise. The processing algorithms used on the reflected signal can predict the extent and geometry of the pipe deformation, and the locations and approximate size of common blockages. The effect of the water level on the frequency of the fundamental mode has also been investigated. It is shown that the technique can be adapted to work reliably in relatively large 600 mm diameter sewer pipes.

First Report of Phytophthora europaea in Oak Forests in the Eastern and North-Central United States

In 2003 and 2004, soils in oak forest ecosystems in nine central and eastern states of the United States were surveyed for Phytophthora spp. Soil samples were collected around healthy and symptomatic trees. Symptoms included dieback of branches, gaps in lateral branch systems, yellowing of foliage, wilting and clustering of leaves, and the presence of epicormic shoots. Soil subsamples were collected in each of the four cardinal directions and at a distance of 1 to 2 m from the base of a tree. The four subsamples were bulked to produce a sample of approximately 2,000 ml. In the laboratory, each sample was mixed thoroughly and a single 250-g subsample was flooded with 500 ml of distilled water and baited with Quercus robur leaflets for 3 to 5 days at 17 to 20°C. Discolored leaflets were examined microscopically (×200) and those with sporangia typical of Phytophthora spp. were plated on PARPNH selective medium (1). Phytophthora europaea was recovered from soil samples collected from Q. alba in West Virginia, Q. rubra in Minnesota, West Virginia, and Wisconsin, Q. phellos in Ohio, and Q. velutina in Pennsylvania. Cultures were identified as P. europaea by their morphological, physiological, and molecular characteristics (4). Average dimensions of nine isolates were determined. Oogonia were 40 ± 3.9 μm in diameter and often had few bullet protuberances and tapered bases; oospores mostly filled the oogonia and averaged 36 ± 3.7 μm; sporangia dimensions averaged 42 ± 6.1 × 30 ± 4.1 μm with a length/width ratio of 1:4. Isolates produced larger oogonia and oospores but had similar sporangia length/width ratios comparable to the species description (4). Growth optimum (5.8 to 6.9 mm day^-1) on V8 juice agar (V8A) occurred at 25°C. On potato dextrose agar, colonies produced dense, felt-like mycelia, often with a central mound of aerial hyphae. DNA also was extracted from eight representative isolates and the internal transcribed spacer (ITS) region of rDNA from each isolate was amplified and sequenced. ITS sequences were identical to those of P. europaea in the NCBI GenBank database (Accession No. DQ313222). Pathogenicity of six isolates (one from each site) was confirmed by wounding stems of 2-year-old Q. alba, Q. rubra, and Q. velutina seedlings and inoculating wounds with V8A plugs (6 mm) containing mycelia; V8A plugs without mycelia were used for controls. Two months after inoculation, P. europaea was reisolated on PARPNH medium from advancing lesions on all inoculated seedlings but was not isolated from control plants. Mean lesion lengths on seedlings inoculated with P. europaea were significantly greater (P < 0.05) than those on control plants; lesions averaged 0.46 cm on Q. alba, 1.38 cm on Q. rubra, and 1.01 cm on Q. velutina. Previously, P. europaea only was reported from oak trees and soil in forests of Austria, France, and Germany (1-4). These findings extend the current distribution of P. europaea and raise questions about its origin and role in the health of oak forests in eastern and north-central United States. Q. alba, Q. phellos, Q. rubra, and Q. velutina are new host associations for P. europaea. References: (1) Y. Balci and E. Halmschlager. For. Pathol. 33:157, 2003. (2) E. Hansen and C. Delatour. Ann. Sci. For. 56:539, 1999. (3) G. Hartmann and R. Blank. Forst Holz. 57:539, 2002. (4) T. Jung et al. Mycol. Res. 106:397, 2002.

Multicolour FISH and quantitative PCR can detect submicroscopic deletions in holoprosencephaly patients with a normal karyotype

Holoprosencephaly (HPE) is the most common structural malformation of the developing forebrain. At birth, nearly 50% of children with HPE have cytogenetic anomalies. Approximately 20% of infants with normal chromosomes have sequence mutations in one of the four main HPE genes (SHH, ZIC2, SIX3, and TGIF). The other non-syndromic forms of HPE may be due to environmental factors or mutations in other genes, or potentially due to submicroscopic deletions of HPE genes. We used two complementary assays to test for HPE associated submicroscopic deletions. Firstly, we developed a multicolour fluorescent in situ hybridisation (FISH) assay using probes for the four major HPE genes and for two candidate genes (DISP1 and FOXA2). We analysed lymphoblastoid cell lines (LCL) from 103 patients who had CNS findings of HPE, normal karyotypes, and no point mutations, and found seven microdeletions. We subsequently applied quantitative PCR to 424 HPE DNA samples, including the 103 samples studied by FISH: 339 with CNS findings of HPE, and 85 with normal CNS and characteristic HPE facial findings. Microdeletions for either SHH, ZIC2, SIX3, or TGIF were found in 16 of the 339 severe HPE cases (that is, with CNS findings; 4.7%). In contrast, no microdeletion was found in the 85 patients at the mildest end of the HPE spectrum. Based on our data, microdeletion testing should be considered as part of an evaluation of holoprosencephaly, especially in severe HPE cases.

Transmission characteristics of tuberculosis in the foreign-born and the Canadian-born populations of Alberta, Canada

SETTING

All notified cases of tuberculosis in the province of Alberta, Canada, 1994-1998.

OBJECTIVE

To compare the transmission characteristics of tuberculosis among foreign-born and Canadian-born cases.

DESIGN

Retrospective analysis using DNA fingerprinting (IS6110 restriction fragment length polymorphism and spoligotyping) and patient information from the Alberta Tuberculosis Registry. Transmission indexes were determined by calculating the average number of culture-positive pulmonary cases generated by a single source case.

RESULTS

Of the 750 cases of active tuberculosis, 437 (58.3%) were in the foreign-born. DNA fingerprinting of Mycobacterium tuberculosis isolates from all 573 culture-positive cases over the 5 years from 1994 to 1998 showed that there was significantly less clustering among foreign-born isolates (9.8%) compared to Canadian-born non-Aboriginal (28.8%) and Aboriginal (44.7%) isolates. The transmission index was significantly higher for males, lower for those > or =65 years of age, and higher for Aboriginals.

CONCLUSION

Although cases of tuberculosis in the foreign-born constitute the majority in Alberta, there is little transmission to other foreign-born or to Canadian-born individuals. Transmission of tuberculosis among the Aboriginal population remains a significant problem in Alberta.

Prognostic markers in node-negative breast cancer: A prospective study

BACKGROUND

Despite years of research, it is still unclear which women with node-negative (N-) breast cancer will need adjuvant chemotherapy and which women are being treated unnecessarily. Our goal was to determine which factors best predicted disease free survival (DFS) or cancer-specific overall survival (OS) and, therefore, select the correct patients for treatment. A total of 11 parameters were measured: estrogen receptor (ER), progesterone receptor (PR), age, race, ploidy status, %G0/G1 (% non-DNA synthesis), %S (% S-phase), cathepsin D status, size, stage, and histologic grade.

RESULTS

In this prospective study, we followed 556 N- patients diagnosed between 1991 and 1996. The tumors were 56% ER+, 51% PR+, 30% diploid, with a mean %S of 8.9%. The level of cathepsin D ranged from 0.50 to 155 pmol/mg of protein with a mean of 42.9 pmol/mg of protein. There were 87 recurrences (16%) and 72 cancer deaths (13%), with a median follow-up of 7.8 years. Ploidy status (p = 0.01), S-phase activity (p = 0.003), G1 phase activity (p = 0.02) and age (p = 0.01) were able to significantly predict DFS in a univariate manner. All of the measurable factors were significant or borderline significant in predicting OS in a univariate manner except for age, race, and ER status. In multivariate analysis with S-phase included, it was the only remaining factor in DFS and OS; with S-phase excluded, age and ploidy status remained as factors for DFS in stepwise regression, while PR, size, and cathepsin D were the remaining factors that predicted cancer-specific OS. The effect of adjuvant treatment on prognosis was also analyzed.

CONCLUSIONS

Both biochemical and clinical parameters have the potential to predict prognosis for N- breast cancer. In this large prospective clinical trial, with a median follow-up of 7.8 years, no individual marker adequately predicted the prognosis for an individual patient. %S activity was the best independent marker, but only 77% of the tumors provided this value. Subset analysis provided improved prognostication, but there were limits to its utility. These data represents a definitive study starting in 1991 and ending in 2002.

Attenuation characteristics of the fundamental modes that propagate in buried iron water pipes

The attenuation of the fundamental non-torsional modes that propagate down buried iron water pipes has been studied. The mode shapes, mode attenuation due to leakage into the surrounding medium and the scattering of the modes as they interact with pipe joints and fittings have been investigated. In the low frequency region the mode predicted to dominate over significant propagation distances approximates a plane wave in the water within the pipe. The established acoustic technique used to locate leaks in buried iron water pipes assumes that leak noise propagates as a single non-dispersive mode at a velocity related to the low frequency asymptote of this water borne mode. Experiments have been conducted on buried water mains at test sites in the UK to verify the attenuation and velocity dispersion predictions.

The epidemiology of tuberculosis among foreign-born persons in Alberta, Canada, 1989-1998: identification of high risk groups

BACKGROUND

To date, there have been no comprehensive epidemiological studies in Canada of the incidence rates of tuberculosis among foreign-born persons. Accurate rate estimates are needed to develop cost-effective strategies for the prevention, control, and ultimate elimination of tuberculosis.

METHODS

Most new immigrants to Canada settle in one of four provinces: Ontario, British Columbia, Quebec and Alberta. Data from the provincial reporting system for tuberculosis, from Statistics Canada censuses and population estimates of Treaty Status Indians provided by the Department of Indian and Northern Affairs Canada, were used to estimate the rate of tuberculosis in Alberta's Canadian-born and foreign-born population between 1989 and 1998.

RESULTS

Age-adjusted tuberculosis case rates per 100,000 person-years were 19.4 and 61.9 in the foreign-born and Canadian-born Treaty Indians-approximately 10 times and 30 times, respectively, higher than the rate in the remainder of the Canadian-born population (2.1/100,000 person-years). Age-specific rates in male and female foreign-born persons were highest at ages 15-34 and > or = 65 years, whereas rates in Canadian-born non-Treaty and Treaty males and females increased incrementally, with a single peak at > or = 65 years. Tuberculosis case rates in the foreign-born varied significantly according to World Bank region and country of birth. By far the highest rates were seen in immigrants to Canada from Asia, in particular Vietnam, the Philippines, China, Hong Kong and India. Most (90%) tuberculosis patients from these countries had not been identified as requiring medical surveillance in Canada after arrival.

CONCLUSION

Immigrants to Alberta from Asia and Treaty Status Indians are at high risk for tuberculosis. Physicians in Alberta who care for foreign-born persons should be aware that their patients are at increased risk for tuberculosis, even if they have been medically cleared during the legal immigration process.

The emergency department is a determinant point of contact of tuberculosis patients prior to diagnosis

SETTING

Metropolitan Edmonton, Canada.

OBJECTIVES

To determine 1) the pre-diagnosis emergency department utilization history of urban tuberculosis patients, and 2) the resource and outcome implications of emergency department utilization by tuberculosis patients pre-diagnosis.

DESIGN

Nested case (emergency department attendee) control (non-emergency department attendee) study of a retrospective cohort of tuberculosis patients.

PATIENTS

All tuberculosis notifications, 1994 through 1998.

MAIN OUTCOME MEASURES

Emergency department utilization during the 6 months antedating the diagnosis and emergency department attendee characteristics; for those notified in 1997 and 1998, hospitalizations, nosocomial infectiousness time, and health care costs.

RESULTS

Of 250 cases of tuberculosis, 117 (47%) made a total of 258 pre-diagnosis emergency department visits. Emergency department use increased the nearer the patient was to diagnosis. Emergency department attendees were more likely to be older, to have smear and/or culture positive respiratory disease, to have a risk factor for progression of infection to disease, and to have a fatal outcome. In 1997 and 1998, emergency department throughput accounted for 70% of all hospitalization days, 95% of all source case nosocomial infectiousness time, and most health care costs of tuberculosis patients pre-diagnosis.

CONCLUSIONS

The emergency department is heavily utilized by urban tuberculosis patients pre-diagnosis. Emergency department throughput of tuberculosis patients pre-diagnosis has major resource and outcome implications. The emergency department may present an opportunity for earlier diagnosis.

Treatment of sperm with subnormal host scores with chymotrypsin/viable pregnancy after IUI

Men with low hypoosmotic swelling test (HOST) scores (<50%) rarely achieve a pregnancy with intercourse or conventional intrauterine insemination (IUI) or even IVF. The defect seems to be related to a toxic factor attached to the sperm that can be transferred to the zona pellucida, which ultimately interferes with implantation. A small case series showed optimistic pregnancy outcome with treatment of the sperm with low HOST scores with chymotrypsin. However, the live pregnancy rate in 90 subsequent IUI cycles in men whose low HOST scores were improved by chymotrypsin was only 3.3%. IVF with ICSI remains the only highly effective treatment of this disorder.

Non-Invasive monitoring of a bioartificial pancreas in vitro and in vivo

Monitoring biochemical processes relevant to the function, survival, and longevity of tissue-engineered pancreatic constructs is important for the development of an optimum construct design as well as patient care management after implantation. In this report we demonstrate the ability of nuclear magnetic resonance (NMR) techniques to monitor aspects of intracellular metabolism, overall morphology, and distribution of a microencapsulation based bioartificial pancreas in vitro and in vivo.

Medical versus surgical treatment of a primary tuberculous pleural peel

The role and timing of surgical decortication in the management of a primary tuberculous pleural peel remains controversial. The present report describes the case of a young man with an extensive primary tuberculous pleural peel that responded dramatically to medical therapy. A serious attempt at surgical decortication three weeks into antituberculous drug therapy may have removed some compressive aspects of the peel, facilitating lung expansion. However, it had almost no measurable impact on the size of peel and was technically very difficult. Response to treatment was measured anatomically (computed tomography scans) and physiologically (pulmonary function tests).