Gradient vector flow based active shape model for lung field segmentation in chest radiographs

Accurate lung field segmentation is crucial to computer-aided diagnosis (CAD) of lung diseases such as lung cancer and tuberculosis (TB). In this paper, we propose a modified gradient vector flow based active shape model (GVF-ASM) for lung field extraction from chest radiographs. Experimental results show that the proposed technique provides around 3-5% improvement over the ASM techniques.

Morphological adaptations of yak (Bos grunniens) tongue to the foraging environment of the Qinghai-Tibetan Plateau

Using light and scanning electron microscopy, the morphological adaptations of the yak (Bos grunniens) tongue to its foraging environment in the Qinghai-Tibetan Plateau were studied. The tongue of the yak was compared with that of cattle (Bos taurus). Compared with cattle, yak tongues are on average 4 cm shorter (P < 0.001), and yak consume forages using the labia oris, rather than by extending the tongue into the harsh environment. The lingual prominence of yak is greater (P < 0.001) and more developed than in cattle. The conical papillae on the prominence surface of yak are slightly larger (diameter: P = 0.068 and height: P = 0.761) and more numerous (P < 0.001) than in cattle. The lenticular papillae on the prominence surface of yak are larger (diameter: P = 0.002 and height: P = 0.115) and more numerous (P = 0.007) than in cattle. Such characteristics may improve the digestibility of forage by the grinding of food between the tongue and the upper palate. Filiform, conical, lenticular, fungiform, and vallate papillae were observed on the dorsal surface of the tongues studied; no foliate papillae were observed. The papillae were covered by keratinized epithelium, which was thicker (P < 0.001) in the yak than in cattle. It is suggested that the development of characteristic filiform papillae, and more numerous lingual gland ducts and mucus-secreting pores in the lenticular, fungiform and vallate papillae, fungiform papillae, probably having mechanical functions, are all morphological adaptations by yak to diets with greater fiber and DM content as provided by the plants within the Qinghai-Tibetan Plateau environment. On average, yak has 26 vallate papillae and cattle have 28. In the vallate papillae of the yak, the taste buds are arranged in a monolayer within the epithelium, whereas they are multilayered (2 to 4) in those papillae in cattle. The number of taste buds in each vallate papillae was less (P < 0.001) in the yak than in cattle. Therefore, the gustatory function of the yak was weaker than in cattle. Yaks graze throughout the year on diverse natural grasslands and have evolved morphological characteristics enabling them to consume a wide variety of plant species, thereby better adapting them to the typically harsh characteristics of their pastures.

Pneumococcal pneumonia: potential for diagnosis through a urinary metabolic profile

Pneumonia, an infection of the lower respiratory tract, is caused by any of a number of different microbial organisms including bacteria, viruses, fungi, and parasites. Community-acquired pneumonia (CAP) causes a significant number of deaths worldwide, and is the sixth leading cause of death in the United States. However, the pathogen(s) responsible for CAP can be difficult to identify, often leading to delays in appropriate antimicrobial therapies. In the present study, we use nuclear magnetic resonance spectroscopy to quantitatively measure the profile of metabolites excreted in the urine of patients with pneumonia caused by Streptococcus pneumoniae and other microbes. We found that the urinary metabolomic profile for pneumococcal pneumonia was significantly different from the profiles for viral and other bacterial forms of pneumonia. These data demonstrate that urinary metabolomic profiles may be useful for the effective diagnosis of CAP.

Fluoroquinolone resistance in renal isolates of Mycobacterium tuberculosis

SETTING

Alberta, Canada, 1990-2003.

OBJECTIVE

Monotherapy of active tuberculosis (TB) promotes drug resistance. Given the common practice of empiric fluoroquinolone (FQ) therapy for urinary tract infections (UTI) and frequent delayed diagnosis of renal TB, we assessed urine Mycobacterium tuberculosis isolates for FQ resistance.

DESIGN

Retrospective study. Urine M. tuberculosis isolates underwent FQ susceptibility testing. Records were reviewed for evidence of FQ exposure and diagnostic delay.

RESULTS

Among 78 culture-positive renal TB patients between 1990 and 2003, initial isolates of M. tuberculosis were available from 74 (94.9%). Three (4.1%) were FQ-resistant. Previous FQ use was confirmed in nine cases (12.2%). FQ-exposed isolates were more likely than non-exposed isolates to be FQ-resistant (2/9, 22.2% vs. 1/65, 1.5%, P = 0.037). Among 41 cases (55.4%) with signs or symptoms of UTI, eight (19.5%) had previous FQ exposure, of which seven (87.5%) had delayed diagnosis. Only 15/33 (45.5%) UTI symptomatic cases without prior FQ exposure had delayed diagnosis (P = 0.050). In 2/8 (25%) UTI symptomatic cases with prior FQ exposure, the M. tuberculosis isolate was FQ-resistant.

CONCLUSION

FQ monotherapy of unsuspected renal TB may delay diagnosis and lead to FQ resistance.

Bronchial anthracofibrosis and tuberculosis in immigrants to Canada from the Indian subcontinent

BACKGROUND

Bronchial anthracofibrosis is a condition of proximal airway narrowing or obliteration and hyperpigmentation in persons with or without a history of occupational dust exposure. It is a bronchoscopic finding that is not uncommonly associated with pulmonary tuberculosis (PTB) in residents of South Korea, Iran and India. It is largely unrecognized in the Western world.

METHODS

We report the frequency of anthracofibrosis in foreign-born PTB patients who underwent bronchoscopy in two cities of Canada. We describe the composition of the pigment in the lungs of patients and speculate on the pathogenesis of anthracofibrosis-associated PTB.

RESULTS

Anthracofibrosis was present in 10/60 (16.7%) foreign-born patients who underwent bronchoscopy and had PTB between 2002 and 2006. Compared to patients from other Asian countries, patients from the Indian subcontinent were more likely to have anthracofibrosis (9/18, 50.0% vs. 1/26, 3.7%, P < 0.001). Carbonaceous particles, silica and silicates predominated in tissue specimens. Proximal airway narrowing appeared to be secondary to mixed dust- and smoke-related anthracofibrosis, PTB, or both.

CONCLUSIONS

Anthracofibrosis is not uncommon in immigrants to Canada from the Indian subcontinent with PTB. PTB may be a responsible or complicating condition in patients with anthracofibrosis.

The art and science of interprofessional education

Interprofessional education (IPE) is increasingly accepted as a core element of health professions education. Its primary function is to prepare health professions students to engage in and deliver interprofessional, team-based healthcare, with the ultimate goal of improving the health and well-being of patients and clients. This paper summarizes findings from 10 interviews with institutional leaders in the field. The goal was to discover core themes than contribute to the art and science of IPE. Thematic challenges and successes are reviewed, and recommendations are provided for further research and for those interested in developing or improving IPE in their own institutions.

Lupus vulgaris occurring in a locus minoris resistentiae

BACKGROUND

The pathogenesis of lupus vulgaris, a form of cutaneous tuberculosis, is not always clear, especially in patients who do not have coexistent extracutaneous tuberculosis and in patients with single lesions.

OBJECTIVES

To report a case of lupus vulgaris in a locus minoris resistentiae (a site of reduced resistance) and to use a unique set of clinical circumstances and laboratory tests to reconstruct the pathogenesis of the lesion and the response to treatment.

CONCLUSION

Lupus vulgaris can occur in a locus minoris resistentiae; local trauma and possibly other factors, such as increased temperature, topical corticosteroids, and the virulence of the infecting strain, may facilitate the growth of Mycobacterium tuberculosis present at a locus minoris resistentiae as a result of a silent bacillemia.

The feasibility of using an 'opt-out' approach to achieve universal HIV testing of tuberculosis patients in Alberta

OBJECTIVE

Universal HIV testing of tuberculosis (TB) patients, defined as testing greater than 80% of incident cases, has been recommended but not achieved in Canada. The objectives of this study were: i) to assess the success of an 'opt-out' approach, whereby HIV testing is routine unless the patient specifically chooses otherwise, and ii) to determine the risk factors for HIV in patients tested before and after this approach was implemented.

METHODS

TB and HIV databases in the province of Alberta were cross-matched before HAART (highly active anti-retroviral therapy) was available (1991-1997), after HAART but before 'opt-out' testing was implemented (1998-2002), and after 'opt-out' testing was implemented (2003-2006), and the HIV status of TB patients in each time period was described. The demographic and clinical characteristics of HIV-positive and -negative TB patients aged 15-64 years were compared.

RESULTS

HIV testing of TB patients increased from 11.5% before HAART, to 44.9% after HAART but before 'opt-out' testing, to 81.9% after 'opt-out' testing was implemented. Between 1991 and 2006, 50 TB patients were diagnosed with HIV co-infection, all in the age group 15-64 years. Among TB patients aged 15-64 years who were HIV tested, those testing positive were significantly less likely to be female and to have respiratory TB and significantly more likely to have both respiratory and non-respiratory TB. The prevalence of HIV positivity in HIV-tested TB patients aged 15-64 years was 7.4% in 2003-2006.

CONCLUSION

Universal HIV testing of TB patients is achievable through 'opt-out' HIV testing.

Clinical spectrum of SIX3-associated mutations in holoprosencephaly: correlation between genotype, phenotype and function

BACKGROUND

Holoprosencephaly (HPE) is the most common structural malformation of the human forebrain. There are several important HPE mutational target genes, including the transcription factor SIX3, which encodes an early regulator of Shh, Wnt, Bmp and Nodal signalling expressed in the developing forebrain and eyes of all vertebrates.

OBJECTIVE

To characterise genetic and clinical findings in patients with SIX3 mutations.

METHODS

Patients with HPE and their family members were tested for mutations in HPE-associated genes and the genetic and clinical findings, including those for additional cases found in the literature, were analysed. The results were correlated with a mutation-specific functional assay in zebrafish.

RESULTS

In a cohort of patients (n = 800) with HPE, SIX3 mutations were found in 4.7% of probands and additional cases were found through testing of relatives. In total, 138 cases of HPE were identified, 59 of whom had not previously been clinically presented. Mutations in SIX3 result in more severe HPE than in other cases of non-chromosomal, non-syndromic HPE. An over-representation of severe HPE was found in patients whose mutations confer greater loss of function, as measured by the functional zebrafish assay. The gender ratio in this combined set of patients was 1.5:1 (F:M) and maternal inheritance was almost twice as common as paternal. About 14% of SIX3 mutations in probands occur de novo. There is a wide intrafamilial clinical range of features and classical penetrance is estimated to be at least 62%.

CONCLUSIONS

Our data suggest that SIX3 mutations result in relatively severe HPE and that there is a genotype-phenotype correlation, as shown by functional studies using animal models.

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.

Empirical treatment of community-acquired pneumonia and the development of fluoroquinolone-resistant tuberculosis

BACKGROUND" Fluoroquinolone (FLQ) antibiotics are not uncommonly prescribed for community-acquired pneumonia that is later proven to be pulmonary tuberculosis (TB). Such FLQ monotherapy may result in FLQ-resistant pulmonary TB.

METHODS

To assess outpatient FLQ use by patients with culture-proven pulmonary TB before diagnosis, TB registries in Alberta and Saskatchewan, Canada, were linked with provincial and federal drug benefit plans. To assess FLQ resistance, a case-control study was performed.

RESULTS

Of 428 patients with pulmonary TB who were covered by a drug benefit plan, 74 (17.3%) had received > or = 1 FLQ prescription during the 6 months immediately before receipt of the diagnosis. Older patients (age, >64 years) were more likely than younger patients (age, 15-64 years) to be prescribed an FLQ (P < .05). Patients who were prescribed an FLQ received a total of 103 prescriptions. Most (54 [73.0%] of 74) patients who were prescribed an FLQ received a single prescription. Most (69 [67.0%] of 103) FLQ prescriptions were written within 90 days before the diagnosis of pulmonary TB. Patients who were prescribed an FLQ were not statistically significantly more likely than matched patients who were not prescribed an FLQ (control subjects) to be infected with FLQ-resistant Mycobacterium tuberculosis. Of 148 isolates of M. tuberculosis from patients and control subjects, 3 were FLQ resistant; all of these isolates were from patients who had received multiple FLQ prescriptions. Patients who had received multiple FLQ prescriptions were more likely than patients who had received a single FLQ prescription to be infected with FLQ-resistant M. tuberculosis (15.0% vs. 0.0%; odds ratio, 11.4; P = .04).

CONCLUSIONS

Outpatient FLQ use, ostensibly for community-acquired pneumonia, is not uncommon among patients with pulmonary TB, especially older patients. Single FLQ prescriptions were not associated with FLQ-resistant M. tuberculosis, whereas multiple FLQ prescriptions were associated with FLQ resistance.

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.

The clinical content of preconception care: nutrition and dietary supplements

Women of child-bearing age should achieve and maintain good nutritional status prior to conception to help minimize health risks to both mothers and infants. Many women may not be aware of the importance of preconception nutrition and supplementation or have access to nutrition information. Health care providers should be knowledgeable about preconception/pregnancy-related nutrition and take the initiative to discuss this information during preconception counseling. Women of reproductive age should be counseled to consume a well-balanced diet including fruits and vegetables, iron and calcium-rich foods, and protein-containing foods as well as 400 microg of folic acid daily. More research is critically needed on the efficacy and safety of dietary supplements and the role of obesity in birth outcomes. Preconception counseling is the perfect opportunity for the health care provider to discuss a healthy eating guideline, dietary supplement intake, and maintaining a healthy weight status.

The clinical content of preconception care: immunizations as part of preconception care

Many vaccine-preventable diseases have serious consequences for the pregnant mother, the fetus, and the neonate. This article reviews the rationale and impact of including vaccinations as part of preconception care and provides recommendations for clinical care. Vaccinations that are recommended highly in preconception care include the hepatitis B and the measles, mumps, and rubella vaccines. The role of human papillomavirus, varicella, diphtheria, tetanus, and pertussis vaccinations as part of preconception care is also discussed.

Adverse events with 4 months of rifampin therapy or 9 months of isoniazid therapy for latent tuberculosis infection: a randomized trial

BACKGROUND

Treatment of latent tuberculosis infection with isoniazid for 9 months is complicated by poor patient adherence and the need for close follow-up of side effects, especially hepatotoxicity. Shorter and safer regimens are needed.

OBJECTIVE

To compare the frequency of adverse events and treatment completion in 2 treatment regimens for latent tuberculosis infection.

DESIGN

Multicenter, randomized, open-label trial.

SETTING

Tuberculosis clinics located in university hospitals in Canada, Brazil, and Saudi Arabia.

PATIENTS

847 patients without a contraindication for rifampin and requiring treatment for latent tuberculosis infection.

INTERVENTION

Four months of daily rifampin therapy or 9 months of daily isoniazid therapy.

MEASUREMENTS

Grade 3 to 4 drug-related adverse events resulting in drug discontinuation (primary outcome), and on-time treatment completion, grade 1 to 2 drug-related adverse events, and changes in liver enzymes and hematologic variables (secondary outcomes).

RESULTS

Seventeen of 422 participants who started isoniazid therapy developed grade 3 to 4 adverse events compared with 7 of 418 who started rifampin therapy (risk difference [rifampin minus isoniazid], -2.3% [95% CI, -5% to -0.1%]; P = 0.040). Grade 3 or 4 hepatitis occurred in 16 of 422 isoniazid recipients compared with 3 of 418 rifampin recipients (risk difference, -3.1% [CI, -5% to -1%]; P = 0.003). Grade 1 or 2 adverse events attributed to study drugs occurred with similar frequency. Asymptomatic reduction in platelet and leukocyte counts were more frequent in rifampin recipients. More patients completed rifampin treatment (78%) than isoniazid treatment (60%) (difference, 18% [CI, 12% to 24%]; P < 0.001]).

LIMITATION

The study did not measure efficacy, and the open-label design may increase the chance of bias in ascertainment of adverse events.

CONCLUSION

Treatment of latent tuberculosis with 4 months of rifampin leads to fewer serious adverse events and better adherence than 9 months of isoniazid. These findings justify a large-scale trial to compare the efficacy of rifampin with that of isoniazid.

Pediatric tuberculosis in Alberta: epidemiology and case characteristics (1990-2004)

BACKGROUND

Pediatric tuberculosis (TB) is important medically and indicative of a public health problem. An understanding of the epidemiology and case characteristics of pediatric TB, in a province that accepts large numbers of immigrants, can inform TB elimination strategy.

METHODS

All cases of pediatric TB notified in Alberta between 1990 and 2004 were identified in the TB Registry. Individual diagnostic criteria were reviewed and case patients were related to a population grid derived from Statistics Canada censuses and population estimates of Status Indians from the Department of Indian and Northern Affairs, Canada. Incidence rates were determined by ethnic group and gender. Clinical/mycobacteriologic case characteristics were compared by ethnic group and birth country.

RESULTS

Among 124 notified cases, 95 (96 episodes) met strict diagnostic criteria: 45 Status Indians, 30 Canadian-born 'other' and 21 foreign-born. Incidence rates were much higher in Status Indians and the foreign-born compared to the Canadian-born 'other'; 10.7, 5.4, and 0.4 per 100,000 person-years, respectively. Among Canadian-born 'other' cases, 12 were Métis and 11 were Canadian-born children of foreign-born parents. Compared to foreign-born cases, Canadian-born cases were more likely to have a source case in Alberta, to be detected through contact tracing, to have primary pulmonary TB, and to have a rural address.

CONCLUSION

Pediatric TB in Alberta is mainly the result of ongoing transmission in Aboriginal peoples and immigration to Canada of persons with latent TB infection. The elimination of pediatric TB will require interruption of transmission in Aboriginal peoples and prevention of disease in immigrants.

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.

Pediatric tuberculosis in Alberta: epidemiology and case characteristics (1990-2004)

BACKGROUND

Pediatric tuberculosis (TB) is important medically and indicative of a public health problem. An understanding of the epidemiology and case characteristics of pediatric TB, in a province that accepts large numbers of immigrants, can inform TB elimination strategy.

METHODS

All cases of pediatric TB notified in Alberta between 1990 and 2004 were identified in the TB Registry. Individual diagnostic criteria were reviewed and case patients were related to a population grid derived from Statistics Canada censuses and population estimates of Status Indians from the Department of Indian and Northern Affairs, Canada. Incidence rates were determined by ethnic group and gender. Clinical/mycobacteriologic case characteristics were compared by ethnic group and birth country.

RESULTS

Among 124 notified cases, 95 (96 episodes) met strict diagnostic criteria: 45 Status Indians, 30 Canadian-born 'other' and 21 foreign-born. Incidence rates were much higher in Status Indians and the foreign-born compared to the Canadian-born 'other'; 10.7, 5.4, and 0.4 per 100,000 person-years, respectively. Among Canadian-born 'other' cases, 12 were Métis and 11 were Canadian-born children of foreign-born parents. Compared to foreign-born cases, Canadian-born cases were more likely to have a source case in Alberta, to be detected through contact tracing, to have primary pulmonary TB, and to have a rural address.

CONCLUSION

Pediatric TB in Alberta is mainly the result of ongoing transmission in Aboriginal peoples and immigration to Canada of persons with latent TB infection. The elimination of pediatric TB will require interruption of transmission in Aboriginal peoples and prevention of disease in immigrants.

Antibiotic from the marine environment with antimicrobial fouling activity

The degradation in performance of submerged marine structures through their colonization by micro- and macrobiota is well known. Historically, toxic surface coatings have been used to control both types of fouling. Legislative requirements worldwide now require alternative non- or minimally toxic coatings to be used. Here we report on the potential for synthetic 2-pentyl-4-quinolinol (PQ), an antibiotic from an Alteromonas sp., as a candidate antifoulant. Hundred micromolar PQ reduces the growth of four marine diatoms that usually grow as biofilms. Furthermore, PQ inhibits the initial adhesive process in Amphora coffeaeformis in a logarithmic dose-dependent manner, but not the adhesion of a Navicula sp., indicating differing adhesive processes in these two diatoms. Treatment of established biofilms with PQ causes a rapid and complete loss of motility in both Amphora and Navicula and eventually, as seen by Sytox Green staining, cell death, and lysis. We conclude that PQ, or one of its chemical analogues, holds promise as an antifoulant molecule for inclusion in marine surface coating.