Growth of Strain SES-3 with Arsenate and Other Diverse Electron Acceptors

The selenate-respiring bacterial strain SES-3 was able to use a variety of inorganic electron acceptors to sustain growth. SES-3 grew with the reduction of arsenate to arsenite, Fe(III) to Fe(II), or thiosulfate to sulfide. It also grew in medium in which elemental sulfur, Mn(IV), nitrite, trimethylamine N-oxide, or fumarate was provided as an electron acceptor. Growth on oxygen was microaerophilic. There was no growth with arsenite or chromate. Washed suspensions of cells grown on selenate or nitrate had a constitutive ability to reduce arsenate but were unable to reduce arsenite. These results suggest that strain SES-3 may occupy a niche as an environmental opportunist by being able to take advantage of a diversity of electron acceptors.

Provider-initiated HIV testing and counselling for TB patients and suspects in Nairobi, Kenya

SETTING

Integrated tuberculosis (TB) and human immunodeficiency virus (HIV) services in a resource-constrained setting.

OBJECTIVE

Pilot provider-initiated HIV testing and counselling (PITC) for TB patients and suspects.

DESIGN

Through partnerships, resources were mobilised to establish and support services. After community sensitisation and staff training, PITC was introduced to TB patients and then to TB suspects from December 2003 to December 2005.

RESULTS

Of 5457 TB suspects who received PITC, 89% underwent HIV testing. Although not statistically significant, TB suspects with TB disease had an HIV prevalence of 61% compared to 63% for those without. Of the 614 suspects who declined HIV testing, 402 (65%) had TB disease. Of 2283 patients referred for cotrimoxazole prophylaxis, 1951 (86%) were enrolled, and of 1727 patients assessed for antiretroviral treatment (ART), 1618 (94%) were eligible and 1441 (83%) started treatment.

CONCLUSIONS

PITC represents a paradigm shift and is feasible and acceptable to TB patients and TB suspects. Clear directives are nevertheless required to change practice. When offered to TB suspects, PITC identifies large numbers of persons requiring HIV care. Community sensitisation, staff training, multitasking and access to HIV care contributed to a high acceptance of HIV testing. Kenya is using this experience to inform national response and advocate wide PITC implementation in settings faced with the TB-HIV epidemic.

Prevalence of vitamin D depletion among subjects seeking advice on osteoporosis: a five-year cross-sectional study with public health implications

We assessed vitamin D nutritional status in unselected consecutive patients seeking advice on osteoporosis. The prevalence of vitamin D depletion ranged from 15-72% depending upon the cut-off levels used for serum 25-hydroxyvitamin D, and the prevalence did not change over the 5 years of the study.

INTRODUCTION

Vitamin D depletion is a significant public health problem and has been studied in different populations using different cut-off levels, but the optimal level is yet to be established.

METHODS

In a cross-sectional study of 2,924 patients seen for osteoporosis advice we determined the prevalence of vitamin D depletion, as assessed by 25-hydroxyvitamin D (25-OHD), using three different cut-off levels stratified by gender, race and the year of the study over 5 years.

RESULTS

Mean age was 68.3 +/- 10.0 years; 90% women and 88% white. Mean 25-OHD level was 24.6 +/- 10 ng/ml and mean PTH was 48.4 +/- 32 pg/ml. The prevalence of vitamin D depletion was 15% with a cut-off level of <15 ng/ml, and rose to 32% and 72% with cut-off levels <20 ng/ml and <30 ng/ml, respectively. The prevalence was higher in men and blacks and remained constant over 5 years, regardless of the cut-off level. The expected inverse relationship between 25-OHD and PTH was observed irrespective of gender or ethnicity.

CONCLUSIONS

The prevalence of vitamin D depletion in patients seeking advice for osteoporosis is high and did not change over the 5 years of the study.

Determinants of influenza vaccination in hard-to-reach urban populations

OBJECTIVE

Influenza vaccination rates among disadvantaged minority and hard-to-reach populations are lower than in other groups. We assessed the barriers to influenza vaccination in disadvantaged urban areas.

METHODS

We conducted a cross-sectional study, using venue-based sampling, collecting data on residents of eight neighborhoods throughout East Harlem and the Bronx, New York City.

RESULTS

Of 760 total respondents, 461 (61.6%) had received influenza vaccination at some point in their life. In multivariable models, having access to routine medical care, receipt of health or social services, having tested positive for HIV, and current interest in receiving influenza vaccination were significantly associated with having received influenza vaccination in the previous year. Of participants surveyed, 79.6% were interested in receiving an influenza vaccination at the time of survey. Among participants who had never previously received influenza vaccination in the past, 73.4% were interested in being vaccinated; factors significantly associated with an interest in being vaccinated were minority race, lower annual income, history of being homeless, being uninsured/underinsured, and not having access to routine medical care.

CONCLUSIONS

Participants who are unconnected to health or social services or government health insurance are less likely to have been vaccinated in the past although these persons are willing to receive vaccine if it were available.

Oxidant regulation of the bivalent cation transporter Nramp1

Nramp1 (murine natural resistance-associated macrophage protein 1 gene)/Slc11a1 (solute carrier family 11 member a1 gene) encodes a bivalent-metal/iron transporter that is expressed within late endosomes/lysosomes of macrophages. A functionally null Nramp1 allele that exhibits impaired bivalent cation transport enables excessive growth of intracellular pathogens. Iron is important for many cellular activities, including defence against pathogens; however, redox-active/free iron can participate in Fenton chemistry that generates reactive oxygen species. Using Raw264.7 cells, non-functional for Nramp1, and stable Nramp1 transfectants, we have examined the effects of impaired bivalent cation transport on macrophage function using glutathione depletion as OS (oxidant stress). Our results demonstrate that OS itself is a signal for increasing Nramp1 transcription and that Nramp1 expression protects against OS. We suggest that OS-mediated protection by Nramp1 function may arise from direct removal of redox-active bivalent cations from a cytosolic pool. We show that OS transcriptional responses are probably mediated by the Sp1 transcription factor.

Influence of dietary factors on the clinical course of ulcerative colitis: a prospective cohort study

BACKGROUND AND AIMS

The causes of relapses of ulcerative colitis (UC) are unknown. Dietary factors have been implicated in the pathogenesis of UC. The aim of this study was to determine which dietary factors are associated with an increased risk of relapse of UC.

METHODS

A prospective cohort study was performed with UC patients in remission, recruited from two district general hospitals, who were followed for one year to determine the effect of habitual diet on relapse. Relapse was defined using a validated disease activity index. Nutrient intake was assessed using a food frequency questionnaire and categorised into tertiles. Adjusted odds ratios for relapse were determined using multivariate logistic regression, controlling for non-dietary factors.

RESULTS

A total of 191 patients were recruited and 96% completed the study. Fifty two per cent of patients relapsed. Consumption of meat (odds ratio (OR) 3.2 (95% confidence intervals (CI) 1.3-7.8)), particularly red and processed meat (OR 5.19 (95% CI 2.1-12.9)), protein (OR 3.00 (95% CI 1.25-7.19)), and alcohol (OR 2.71 (95% CI 1.1-6.67)) in the top tertile of intake increased the likelihood of relapse compared with the bottom tertile of intake. High sulphur (OR 2.76 (95% CI 1.19-6.4)) or sulphate (OR 2.6 (95% CI 1.08-6.3)) intakes were also associated with relapse and may offer an explanation for the observed increased likelihood of relapse.

CONCLUSIONS

Potentially modifiable dietary factors, such as a high meat or alcoholic beverage intake, have been identified that are associated with an increased likelihood of relapse for UC patients. Further studies are needed to determine if it is the sulphur compounds within these foods that mediates the likelihood of relapse and if reducing their intake would reduce relapse frequency.

A randomized control trial of an Ultra-Short zidovudine regimen in the prevention of perinatal HIV transmission in rural Zimbabwe

OBJECTIVE

To assess the practicality and effectiveness of an Ultra-Short zidovudine regimen for prevention of perinatal HIV transmission in rural Zimbabwe.

DESIGN

Double-blinded placebo-controlled randomized clinical trial.

SETTING

The Salvation Army Howard Hospital, a district hospital in rural Zimbabwe.

SUBJECTS

222 HIV positive pregnant women presenting for antenatal care prior to 36 weeks were randomized. Twenty nine women were lost to follow up.

INTERVENTION

In the Thai regimen, mothers received zidovudine (300 mg po bid) from 36 weeks gestation until labour, and zidovudine (300 mg po q3h) during labour, and the neonates received a placebo. In the Ultra-Short regimen, the mothers received a placebo from 36 weeks to labour, then zidovudine (300 mg po q3h) in labour. The neonates received zidovudine (2 mg/kg po qid) for the first three days of life.

MAIN OUTCOME MEASURE

Infant HIV RNA status at six weeks of life.

RESULTS

Results were available for 90 infants from the Thai group and 89 infants from the Ultra-Short group. Infant HIV seroconversion rates at six weeks of life were 18.9% (95%CI 10.8 to 27.0) with the Thai regimen, and 15.7% [95% Confidence Interval (CI) 8.1 to 23.4] with the Ultra-Short regimen. The upper bound of seroconversion in the Ultra-Short group was lower than the 25% seroconversion boundary that was specified to show equivalence.

CONCLUSIONS

Although the Ultra-Short regimen has equivalent efficacy to the Thai regimen, it also has many practical advantages. Ultra-Short is thus a preferable protocol.

Current status of an antireflux procedure in laparoscopic Heller myotomy

BACKGROUND

Persistent dysphagia and postoperative gastroesophageal reflux (GER) are the most cited reasons for surgical failure of laparoscopic Heller myotomy. Adding an antireflux procedure to Heller myotomy has been proposed to prevent reflux. We hypothesized that an antireflux procedure added to laparoscopic Heller myotomy has little effect on preventing the symptoms or long-term sequelae of GER in achalasia patients.

METHODS

We performed a meta-analysis of studies on human subjects reported in the English language literature from 1991 to 2001 years.

RESULTS

An antireflux procedure accompanied laparoscopic myotomy in 15 studies with 532 patients. In 6 studies of 69 patients, no antireflux procedure was added to laparoscopic myotomy. Follow-up was available on 489 patients (92%) with partial fundoplication. The rate of GER diagnosed in pH studies was 7.9% (18 of 228 patients studied), whereas only 5.9% of patients experienced symptoms of GER (29 of 489 patients followed). Of the 69 patients without fundoplication, 47 (68%) were available for follow-up. Forty patients (85%) were studied with pH monitoring postoperatively, with 4 (10%) demonstrating reflux. Six (13%) of 47 patients had symptoms of GER. The difference in the rate of GER diagnosed in postmyotomy pH studies in wrapped and nonwrapped patients was not significant (7.9 vs 10%, respectively; p = 0.75). There was also no significant difference in the incidence of postmyotomy GER symptoms in wrapped and nonwrapped patients (5.9 vs 13% respectively; p = 0.12).

CONCLUSIONS

Reflux is not necessarily eliminated with the addition of a partial fundoplication. Based on the published data, recommendations cannot be made regarding the efficacy of adding an antireflux procedure to laparoscopic Heller myotomy. Prospective randomized study is needed to clarify the role of an antireflux procedure after laparoscopic Heller myotomy.

Defining relapse of ulcerative colitis using a symptom-based activity index

BACKGROUND

Several tools exist to assess disease activity in patients with ulcerative colitis (UC), but a definition of relapse does not exist. The aim of the study was to determine the score in the Simple Clinical Colitis Activity Index (SCCAI) that defined relapse. The reliability and validity of the SCCAI when self-administered was also examined.

METHODS

Patients with UC routinely attending hospital completed the SCCAI questionnaire, which was later administered by their clinician blinded to the scoring process. In the absence of a gold standard definition of relapse, a subjective global assessment of disease status was made by the clinician. The SCCAI was evaluated in a separate cohort of patients.

RESULTS

Seventy-one presentations were analysed; mean age 48 years, 49% male, 37% relapse rate. The mean patient score was 4.2 (range 0-14) and mean physician score 3.8 (0-14). A score of 5 or more defined relapse with 92% sensitivity, 93% specificity, 88% positive predictive value and 95% negative predictive value. The difference between the scores obtained by the patient and clinician (0.35, 95% CI 0.09-0.62) was small. Correlation with a more complex symptom and laboratory-based activity index was very high (r = 0.79, P < 0.01). The index was quick to use and comparative results for sensitivity and specificity were recorded in the second cohort of patients.

CONCLUSIONS

The SCCAI is a simple tool that can be accurately and quickly self-administered, correlates well with a more complex disease activity index, and can be used to define relapse of UC with high specificity and sensitivity.

c-Myc represses the murine Nramp1 promoter

The Nramp1 (natural resistance-associated macrophage protein 1) gene modulates the growth of intracellular pathogens and encodes a divalent cation transporter within lysosomes/late endosomes of macrophages. Nramp1 modulates the cytoplasmic iron pool. Wu, Polack and Dalla-Favera [(1999) Science 283, 676-679] showed reciprocal control of H-ferritin and IRP2 by c-Myc, and suggest that c-Myc regulates genes to increase cytoplasmic iron. A role for c-Myc in Nramp1 regulation was evaluated. Co-transfection studies show that c-Myc represses Nramp1 promoter function. Five non-canonical Myc-max binding sites (E-box) identified within the Nramp1 5'-flanking sequence are not responsible for the inhibitory effects of c-Myc on Nramp1 expression. An initiator(s) adjacent to the transcription-initiation site is a candidate for the inhibition observed. Results are consistent with a role for Nramp1 removing iron from the cytosol and antagonizing c-Myc function.

Visual P3 findings in Mission Indian youth: relationship to family history of alcohol dependence and behavioral problems

Native Americans have some of the highest rates of alcohol abuse and dependence, yet risk factors for problem drinking remain relatively unknown. The amplitude of the P3 component of the event-related potential (ERP) has been suggested to be an index of 'vulnerability to alcoholism', especially when it is elicited by visual tasks in younger individuals. Visual P3 tasks, however, have not been previously investigated in Native American youth. One hundred and four Mission Indian youth between the ages of 7 and 13 years participated in the study. ERPs were collected using two visual target paradigms: a facial discrimination and an estimation of line orientation task. Analyses of covariance revealed that participants with a first degree family history of alcoholism had lower P3 component amplitudes in frontal leads to the facial discrimination task. Lower P3 amplitudes, in posterior areas, were found in the line discrimination task in children who scored above the 75th percentile in delinquent behaviors on the Achenbach Child Behavior Checklist. These findings are consistent with investigations in non-Indian populations demonstrating that the late positive component of the event related potential is sensitive to both familial history of alcohol dependence as well as personal history of externalizing behaviors.

Role of sample adequacy in fine needle aspiration biopsy of palpable breast lesions

BACKGROUND

The role of fine needle aspiration biopsy (FNAB) in breast lesions remains uncertain because its accuracy has been questioned. We hypothesized that this is related to failure to define standards for adequacy of sample preparation.

METHODS

We reviewed cytology and pathology reports from 351 patients undergoing FNAB at a 350-bed community, university-affiliated teaching hospital over a 2-year period. Patients were included if they had an open biopsy within 2 years of an FNAB of the same lesion. Cytology reports were reviewed by a cytopathologist unaware of the clinical setting or subsequent histology; surgeons unaware of the cytology reports reviewed histology reports. Cytological diagnoses were benign, likely benign, probable cancer, and definite cancer. Samples were characterized as satisfactory, less than optimal (few mammary epithelial clusters), or inadequate (no mammary epithelial clusters.) We assessed the proportion of inadequate samples, the accuracy of FNAB, and the influence of sample adequacy upon FNAB sensitivity.

RESULTS

Ninety-nine (28%) FNABs were inadequate, 77 (22%) less than optimal, and 175 (50%) satisfactory. Ninety-five patients (27%) had a final diagnosis of malignancy. FNABs classified as satisfactory or less than optimal and characterized as benign (n = 102) had a negative predictive value (NPV) of 0.91; those termed definite cancer (n = 43) had a positive predictive value (PPV) of 0.98. Only 10% of all cancers were identified in the 28% of FNABs that were classified as inadequate (P <0.01).

CONCLUSIONS

We concluded that too few FNABs are performed in a fashion that permits definitive cytological interpretation. Inadequate FNABs are less likely to detect malignancy. After excluding inadequate preparations, FNABs interpreted as definite cancer and as benign are highly accurate in identifying patients with and without cancer.

Auditory P3 findings in mission Indian youth

OBJECTIVE

Native Americans have some of the highest rates of alcohol abuse and dependence, yet potential biological risk factors associated with the problem drinking seen in many tribes remain relatively unknown. In this study, the amplitude of the P3 component of the event-related potential (ERP), a measure associated with risk for alcoholism in European-American youth, was investigated in Mission Indians.

METHOD

The study participants were Mission Indian children and adolescents (N = 68, 37 male) between the ages of 7 and 13 years. ERPs were collected using two auditory "oddball" paradigms: an easy and a difficult discrimination task. P3 amplitude and latency were statistically evaluated as a function of age, gender, degree of Native American heritage (NAH) and family history (FH) of alcohol dependence.

RESULTS

P3 latency was found to vary as a function of age and gender, with girls demonstrating greater decreases in latency with age than boys. suggesting a faster maturation time. Whereas there were no significant relationships between NAH and P3 latency, those participants with at least one alcoholic parent had longer P3 latencies elicited by the difficult auditory task. No significant relationships were found between P3 amplitude generated to the target tones and any of the variables (age, gender, FH, NAH).

CONCLUSIONS

Mean P3 amplitudes and latencies obtained from these Mission Indian youth were within the range of those values reported in the literature for samples of children and adolescents of other ethnicities. Although the amplitude of the P3 ERP measure has been associated with FH of alcoholism in studies of predominantly European-American individuals, P3 amplitudes generated in response to these auditory tasks did not robustly differentiate Mission Indian children and adolescents who may be at higher risk for alcoholism from those presumed to be at lower risk.

Laparoendoscopic approaches to occult gastrointestinal bleeding

Identification of sites of small bowel hemorrhage remains a difficult problem. Endoscopy performed in association with surgery often proves successful when other attempts have failed. In attempts to minimize morbidity and even increase accuracy, surgeons have explored combining laparoscopic techniques with endoscopy. Although published experiences remain few, expectations remain high.

EEG asymmetry: relationship to mood and risk for alcoholism in Mission Indian youth

BACKGROUND

Left frontal electroencephalogram (EEG) alpha dominance has been hypothesized to be related to depressed mood as well as aversive motivation and emotion. However, few studies have prospectively evaluated electroencephalogram asymmetry during development in high-risk adolescents and children.

METHODS

EEG alpha asymmetry was investigated in 134 Mission Indian children who were between 7 and 13 years of age. The relationships between electroencephalogram alpha asymmetry and age, gender, parental history of alcohol dependence, Native American heritage, and mood/ approach behaviors were explored.

RESULTS

No significant relationship was found between frontal alpha asymmetry and age, gender, or behavioral measures of depressed mood and/or approach behaviors. However, participants with > or = 50% Native American heritage were significantly more likely to have greater electroencephalogram alpha power in the left frontal cortex than in the right.

CONCLUSIONS

The present findings suggest that the hypothesized relationship between EEG alpha asymmetry and measures of depressed mood, aversive motivation, and emotion may not be universal in all age or ethnic groups. Additionally, though the relationship between greater degrees of Native American heritage and alpha asymmetry are not as yet clear, we suggest it may be more related to substance abuse than depression in this population of Mission Indians.

Profiling clonality and progression in multiple premalignant and malignant oral lesions identifies a subgroup of cases with a distinct presentation of squamous cell carcinoma

A cohort of head and neck cancer patients, without exposure to tobacco and alcohol, presented with multiple preneoplastic and neoplastic lesions, the natural history of which may span several decades. Examination of these cases provides an opportunity to study the relationship between genetic, morphological, and clonal progression in these fields and establish whether they represent a unique presentation of squamous cell carcinoma. The presence of a common novel microsatellite allele, a common breakpoint or concordant allelic imbalance at multiple loci, reveals that a high proportion of these serial lesions arise due to spread of a precursor. The tumors arising in these patients were typically nonaggressive, although metastases developed at a late stage, supporting the notion that the genotype results in a phenotype with a propensity for lateral spread, rather than invasion. Different genetic aberrations were detected in morphologically similar phenotypes such that no consistent early or late events were associated with development of premalignant lesions. Combining information about the clinicopathological features and histological examination of the margins with that derived from clonality analysis reveals that a subgroup of patients, without exposure to the traditional risk factors associated with this disease, developed multiple clonally related oral lesions and represents a unique presentation of head and neck squamous cell carcinoma. We suggest the term clonal cancerization to describe multiple premalignant and malignant lesions when there is conclusive evidence that they arise due to lateral spread from a common precursor.

Effects of age and parental history of alcoholism on EEG findings in mission Indian children and adolescents

BACKGROUND

Many, but not all, Native American tribes have some of the highest rates of alcohol abuse and dependence. Yet, risk factors for the development of problem drinking in these high risk groups remain largely unknown. In primarily Euroamerican populations, electrophysiological variables have been associated with risk for alcoholism. The EEG has a specific developmental time course that has been described in a diverse set of ethnic groups, but it has not been described in Native American youth. In addition, the relationship between EEG development and risk for alcoholism in Indian youth has not been previously studied.

METHODS

Clinical ratings and spectral characteristics of the resting EEG were investigated in 140 Native American Mission Indian children and adolescents between the ages of 7 and 13 years. The specific aims of the study were to (1) investigate the relationship of age and gender with EEG spectral variables to determine if this population conforms to similar trends from previously published data in other ethnic groups and (2) to determine whether children with a parental history of alcoholism differ from those without alcoholic parents on EEG spectral parameters.

RESULTS

No excess of abnormal EEG activity was found in this sample of Native American youth. Age, but not gender, was found to have a significant effect on EEG spectral characteristics with younger children (7-11 years old), having significantly more power in slow activity (0.5-7.5 Hz) and in alpha power (8-12 Hz) as well as slower alpha frequencies than older children (12-13 years old). Consistent with other studies of Native American youth, 66% of the children and adolescents participating in this study had at least one parent who had a lifetime diagnosis of alcohol dependence. However, an ANCOVA that covaried for age and gender revealed no significant differences in power or frequency characteristics of the EEG on the basis of parental history of alcoholism.

CONCLUSIONS

These studies suggest that this sample of Mission Indian children, despite high levels of parental alcohol dependence and low socioeconomic status, show normal EEG development. As yet, no relationship has been found between any specific EEG phenotype and parental history of alcoholism in this population, however, further EEG maturation may be necessary before any relationships can be fully delineated.

Suppression of the radiation-sensitive phenotype of hamster irs1 and irs2 strains selected for resistance to 3-aminobenzamide

PURPOSE

The radiosensitive hamster cell lines irs1 and irs2 have phenotypic similarities to cells defective in the early response to DNA-damaging agents as a result of mutations of the genes encoding poly(ADP-ribose)polymerase (PARP) or ataxia-telangiectasia mutated (ATM). Whether modification of PARP activity through selection of strains resistant to 3-aminobenzamide (3-AB) would affect the radiosensitive phenotype of irs1 and irs2 was examined.

MATERIALS AND METHODS

3-AB-resistant strains of irs1, irs2 and their parent line V79 were established and their sensitivity to DNA-damaging agents was measured. In some 3-AB-resistant strains, the radiation resistance of DNA synthesis and the induction of apoptosis were also assayed. Additionally, a number of aspects of PARP function were measured.

RESULTS

Independently selected 3-AB-resistant strains of irs2 showed nearly complete suppression of radiation sensitivity, sensitivity to topoisomerase inhibitors, and radioresistant DNA synthesis. 3-AB-resistant strains of irs1 showed partial suppression of phenotype while 3-AB-resistant strains of V79 had no sensitivity changes. The induction of apoptosis in 3-AB-resistant strains of irs2 required substantially higher radiation doses than for irs2 itself. 3-AB-resistant strains had no detectable alteration of PARP level or cleavage following ionizing irradiation and there were no mutations in the PARP gene.

CONCLUSIONS

Suppression of radiosensitivity associated with 3-AB resistance has important implications for mechanisms of tolerance to damage because it is able to override responses associated with specific genetic defects.