The bleach microscopy method and case detection for tuberculosis control

The World Health Organization (WHO) and the International Union Against Tuberculosis and Lung Disease (The Union) recommend direct sputum smear microscopy for tuberculosis (TB) case finding in resource-poor settings. This method is associated with poor sensitivity. Digestion of sputum with bleach prior to smear preparation has been reported to increase sensitivity. Some workers, having reviewed the relevant literature, have called for the WHO and The Union to advocate for a shift to this methodology for TB case finding. This article highlights deficiencies in the scope and detail of available evidence, and cautions against the premature, and possibly counter-productive, adoption of so-called 'bleach microscopy'. Further well-guided research is required to answer policy-relevant gaps in our knowledge about this promising technology.

Nitric oxide release is induced by dopamine during illumination of the carp retina: serial neurochemical control of light adaptation

Several lines of indirect evidence have suggested that nitric oxide may play an important role during light adaptation of the vertebrate retina. We aimed to verify directly the effect of light on nitric oxide release in the isolated carp retina and to investigate the relationship between nitric oxide and dopamine, an established neuromodulator of retinal light adaptation. Using a biochemical nitric oxide assay, we found that steady or flicker light stimulation enhanced retinal nitric oxide production from a basal level. The metabotropic glutamate receptor agonist L-amino-4-phosphonobutyric acid, inhibited the light adaptation-induced nitric oxide production suggesting that the underlying cellular pathway involved centre-depolarizing bipolar cell activity. Application of exogenous dopamine to retinas in the dark significantly enhanced the basal production of nitric oxide and importantly, inhibition of endogenous dopaminergic activity completely suppressed the light-evoked nitric oxide release. The effect of dopamine was mediated through the D1 receptor subtype. Imaging of the nitric oxide-sensitive fluorescent indicator 4,5-diaminofluorescein di-acetate in retinal slices revealed that activation of D1 receptors resulted in nitric oxide production from two main spatial sources corresponding to the photoreceptor inner segment region and the inner nuclear layer. The results taken together would suggest that during the progression of retinal light adaptation there is a switch from dopaminergic to nitrergic control, probably to induce further neuromodulatory effects at higher levels of illumination and to enable more efficient spreading of the light adaptive signal.

Always look beyond the stones: hyperoxaluria overlooked

We report a case which demonstrates the disastrous consequences of late diagnosis of hyperoxaluria in a 24-year-old woman with nephrocalcinosis, a staghorn calculus and recurrent urinary tract infections. Her initial management at another hospital included multiple percutaneous nephrostomies and lithropsies. Metabolic screening was not undertaken. Hyperoxaluria was finally diagnosed by elevated urine oxalate (1.235 mmol/24 h) and renal biopsy, by which time there was already significant reduction of renal function. A diagnosis of hyperoxaluria type I was confirmed by liver biopsy. Despite starting pyridoxine and crystallization inhibitors, her renal function deteriorated, requiring hemodialysis and she was referred for combined liver-renal transplantation. Clinical clues of primary hyperoxaluria type I are a positive family history or presentation with severe renal stones at an unusually early age. Irrespective of the above, all patients with first presentation of renal calculi should undergo metabolic screening, including urine oxalate.

Renal-related deaths in Australia 1997−1999

BACKGROUND

Despite marked increases in cases of treated end-stage renal disease in Australia, little is known about renal disease mortality.

AIMS

To quantify the contribution of renal diseases to mortality in Australia and to explore the relationship between renal disease and other common diseases as causes of death.

METHODS

Data from the Australian Bureau of Statistics on underlying and associated causes of death (based on death certificates) were examined for deaths occurring in 1997-1999 and registered by the end of 1999. Causes of death were coded according to the International Classification of Diseases, 10th Revision (ICD-10). Several causes outside the ICD-10 chapter on diseases of the genito-urinary system (e.g. diabetic renal disease, hypertensive renal disease and congenital malformations of the kidney) were included as renal.

RESULTS

Of 378,832 recorded deaths, renal disease was coded as the underlying cause for 7888 (2.1%) and as an associated cause for an additional 28,012 (7.4%). Almost all renal deaths (98.4%) had at least one other cause of death recorded on the death certificate.

CONCLUSIONS

The contribution of renal disease to Australian mortality has been underestimated because of historical reliance on a single (underlying) cause of death. Deaths involving renal disease usually occur in the context of multiple coexisting chronic and/or acute conditions.

Detection of Nitrated Benzene Metabolites in Bone Marrow of B6C3F1 Mice Treated with Benzene

Benzene, a constituent of cigarette smoke, is a human leukemogen and induces bone marrow toxicity. The mechanism of benzene-induced toxicity is not well-established. We hypothesized that relatively high levels of nitric oxide formed in bone marrow can react with oxygen and/or superoxide anion that is generated during redox cycling of ring-hydroxylated benzene metabolites to yield peroxynitrite as well as other NO-derived intermediates. Peroxynitrite can either directly damage cellular macromolecules or form nitrated toxic metabolites. Toward this end, we investigated whether nitro derivatives of benzene are formed in bone marrow of mice treated with benzene. First, we have characterized products formed during activation of benzene in Fenton's system in the absence or presence of NO-releasing compound in vitro by GC/MS. The result of above experiment prompted us to determine whether similar products can be formed in vivo. Groups of B6C3F1 male mice, eight weeks of age, were given a single intraperitoneal dose of [14C]benzene (400 mg/kg body wt, 9.7 mCi/mmol) or an equal dose of unlabeled benzene in corn oil, and the mice were killed 0.5 or 1 h posttreatment. The control group received only vehicle injections. Organic solvent extractable metabolites from bone marrow, liver, lungs, and blood of mice treated with [14C]benzene were identified by comparison of their respective retention times under two different HPLC conditions with authentic standard samples. These metabolites were further characterized by comparison of their GC/MS properties to those of reference standards. Nitro metabolites, namely, nitrobenzene, nitrobiphenyl, and nitrophenol isomers, were detected in the bone marrow of the mice 1 h after benzene treatment. Formation of nitro derivatives in other tissues was either not observed or was significantly less than that formed in bone marrow. This study clearly demonstrates that nitric oxide is a contributor to benzene metabolism and can form nitrated derivatives that may, in part, account for bone marrow toxicity.

Twenty year comparison of a Bjork-Shiley mechanical heart valve with porcine bioprostheses

OBJECTIVE

To compare survival and outcome in patients receiving a mechanical or bioprosthetic heart valve prosthesis.

DESIGN

Randomised prospective trial.

SETTING

Tertiary cardiac centre.

PATIENTS

Between 1975 and 1979, patients were randomised to receive either a Bjork-Shiley or a porcine prostheses. The mitral valve was replaced in 261 patients, the aortic in 211, and both valves in 61 patients. Follow up now averages 20 years.

MAIN OUTCOME MEASURES

Death, reoperation, bleeding, embolism, and endocarditis.

RESULTS

After 20 years there was no difference in survival (Bjork-Shiley v porcine prosthesis (mean (SEM)): 25.0 (2.7)% v 22.6 (2.7)%, log rank test p = 0.39). Reoperation for valve failure was undertaken in 91 patients with porcine prostheses and in 22 with Bjork-Shiley prostheses. An analysis combining death and reoperation as end points confirmed that Bjork-Shiley patients had improved survival with the original prosthesis intact (23.5 (2.6)% v 6.7 (1.6)%, log rank test p < 0.0001); this difference became apparent after 8-10 years in patients undergoing mitral valve replacement, and after 12-14 years in those undergoing aortic valve replacement. Major bleeding was more common in Bjork-Shiley patients (40.7 (5.4)% v 27.9 (8.4)% after 20 years, p = 0.008), but there was no significant difference in major embolism or endocarditis.

CONCLUSIONS

Survival with an intact valve is better among patients with the Bjork-Shiley spherical tilting disc prosthesis than with a porcine prosthesis but there is an attendant increased risk of bleeding.

Cancer in Indigenous Australians: a review

OBJECTIVES

To summarize for the first time evidence of the impact of cancer on Indigenous Australians.

METHODS

Medline search of peer-reviewed scientific journals, and extensive search of reports of government agencies, publications of cancer registries and non-government organizations, and other non-peer-reviewed sources.

RESULTS

Indigenous Australians have much higher incidence rates than other Australians of cancers of the lung, liver, and cervix; but much lower rates of cancers of the breast, colon and rectum, prostate, melanoma of skin, and lymphoma. Some of these differences can be explained, in part at least, by differences in risk factor prevalence. Indigenous Australians also have higher mortality and lower survival from cancer as a whole than other Australians. More advanced disease at diagnosis, and possibly poorer treatment, are partly responsible for these differences, but other factors may also be involved.

CONCLUSIONS

Less accessible and less effective health programs are as great a problem for cancer control as for other aspects of Indigenous health in Australia. Major improvements in preventive services, screening, primary care, and specialist treatment services are required to reduce cancer incidence and improve cancer outcomes for Australia's Indigenous people.

Characterization of Salmonella associated with pig ear dog treats in Canada

In the summer of 1999, the incidence of Salmonella enterica serotype Infantis infections in Alberta rose dramatically. Subsequent laboratory and epidemiological investigations established that an outbreak of human disease caused by this organism was occurring across Canada and was associated with pet treats for dogs produced from processed pig ears. Laboratory investigations using phage typing and pulsed-field gel electrophoresis (PFGE) established that isolates of Salmonella serotype Infantis from pig ear pet treats and humans exposed to pig ear pet treats comprised a well-defined subset of all isolates analyzed. Of the 53 subtypes of Salmonella serotype Infantis obtained around the time of the outbreak as defined by PFGE and phage typing, only 6 subtypes were associated with both human infection and isolation from pig ears. Together with information from epidemiological studies, these investigations established pig ear pet treats as the cause of the Salmonella serotype Infantis outbreak. The results are consistent with a model in which contaminated pig ear pet treats constitute a long-term, continuing vehicle for infection of the human population rather than causing temporally delimited point-source outbreaks. During the course of this outbreak, several other Salmonella serotypes were also isolated from pet treats, suggesting these products may be an important source of enteric infection in both humans and dogs. Though isolates of Salmonella serotypes other than Salmonella serotype Infantis from pet treats were also subjected to PFGE and phage typing, no link with human disease could be definitively established, and the contribution of pig ear pet treats to human disease remains unclear. Elimination of bacterial contamination from pet treats is required to reduce the risk of infection from these products.

Functional effect of adeno-associated virus mediated gene transfer of aromatic L-amino acid decarboxylase into the striatum of 6-OHDA-lesioned rats

In animal models of Parkinson's disease, gene transfer of aromatic L-amino acid decarboxylase (AADC) leads to an increase in the capacity of the striatum to decarboxylate exogenous L-DOPA. However, the functional effects of enhanced L-DOPA to dopamine conversion have not been explored. Here, we show that following adeno-associated virus (AAV)-AADC transduction, the transgenic AADC is able to decarboxylate exogenous L-DOPA more efficiently so that a dose of L-DOPA ineffective before gene transfer elicits a motor asymmetry (rotational behavior) following gene transfer. Furthermore, rotation scores showed a strong correlation with AADC activity in the lesioned striatum, thus allowing for behavioral screening of successful gene transfer in the brain. In animals receiving AAV2-AADC, dopamine production was restored to 50% of normal levels 12 weeks after the infusion. Microdialysis experiments demonstrated an in vivo enhanced conversion of L-DOPA to dopamine, but no storage capacity as dopamine was released to the extracellular space in a continuous, nonregulated fashion. In addition to the potential clinical benefit of improving decarboxylation efficiency in Parkinson's disease, our approach may be relevant for the treatment of AADC deficiency, a rare, autosomal recessive disorder causing a severe movement disorder and progressive cognitive impairment.

Self-assessed health among indigenous Australians: how valid is a global question?

OBJECTIVES

This study assessed the validity of a global measure of self-assessed health among Indigenous Australians.

METHODS

Logistic regression was used to identify factors associated with self-assessed health in a nationally representative sample.

RESULTS

Among 8782 adult respondents, poorer self-assessed health was strongly associated with several factors, including age, number of health conditions, and recent health actions. The association with health conditions was attenuated when the respondent's primary language was not English.

CONCLUSIONS

Self-assessed health may be a valid measure among indigenous Australians whose primary language is English. However, although the measure draws on common experiences of health and illness, it may obscure differences in how people incorporate these experiences into social actions.

Treatment of steroid-refractory acute graft-versus-host disease with anti-CD147 monoclonal antibody ABX-CBL

ABX-CBL, an immunoglobulin M murine monoclonal antibody, recognizes CD147 and initiates cell killing through complement-mediated lysis. In a dose-finding trial, 27 patients with steroid-refractory acute graft-versus-host disease (GVHD) received ABX-CBL at 0.01 (presumed no effect dose), 0.1, 0.2, or 0.3 mg/kg per day, and an additional 32 patients were given ABX-CBL at 0.2 or 0.15 mg/kg per day. All patients had undergone allogeneic transplantation for malignant or nonmalignant disorders and received GVHD prophylaxis, generally with methotrexate- and cyclosporine-containing regimens. None responded to methylprednisolone, given for a minimum of 3 days. ABX-CBL was started 20 to 236 (median, 47) days after transplantation; it was given for 7 consecutive days and was followed by 2 infusions per week for 2 more weeks. Among 51 patients evaluable for efficacy, 26 (51%) responded, including 13 with complete responses (CR) and 13 with partial responses (PR). CR lasting 14 days or longer or PR lasting 7 days or longer occurred in 21 (41%; 8 CR, 13 PR) patients, including 19 of 43 (44%) patients who received 0.1 to 0.3 mg/kg ABX-CBL and 2 of 8 (25%) patients given 0.01 mg/kg per day. Myalgias at doses 0.2 mg/kg or greater were dose limiting and resolved without sequelae. Causes of death included organ failure, progressive GVHD, and infection. No death was attributed to ABX-CBL. At 6 months after the initiation of ABX-CBL therapy, 26 (44%) patients were surviving. These results are encouraging. Further studies on the use of ABX-CBL in the management of GVHD are warranted.

Effect of extended immunosuppressive drug treatment on B cell vs T cell reconstitution in pediatric bone marrow transplant recipients

Allogeneic bone marrow transplantation (BMT) is an effective therapy for a variety of malignancies and blood disorders, but rarely serves as a frontline treatment because of numerous, potential complications. Important and frequent complications relate to the profound immunosuppression that inevitably occurs during the first several months following treatment. To better elucidate and subsequently improve immune reconstitution, we examined T and B cell subsets among 43 pediatric BMT recipients in a retrospective study. We found that the relative numbers of T cells and B cells (T:B ratios) were discordant and highly variable among patients at day approximately 100 after BMT. Further investigation of BMT parameters identified a strong correlation between T:B ratios and immunosuppressive drug treatments, providing an explanation for variable lymphocyte reconstitution profiles. Results suggest that: (1) immunosuppressive therapy inhibits B cell expansion more strongly than T cell expansion following BMT; (2) WBC and absolute lymphocyte counts fail to reveal profound B cell immunodeficiencies in some BMT patients; and (3) routine analyses of T:B ratios serve to identify patients warranting close follow-up and extended supportive immunotherapy.

Bisphosphonates in renal osteodystrophy

The present review considers the role that bisphosphonates might have in patients with renal failure. Although bisphosphonates are widely used to reduce fracture risk in patients with osteoporosis, few studies have documented their effect in patients with renal osteodystrophy. The pathogenesis of bone loss after renal transplantation and the role of the recently identified osteoprotegerin/receptor activating nuclear factor-kappaB system is described. Inhibition of bone resorption may prove beneficial when high bone turnover is present, but there are potential drawbacks to widespread use of bisphosphonates. These issues are discussed, with emphasis placed on reports published within the past 18 months.

Characterization of glycated hemoglobin in diabetic patients: usefulness of electrospray mass spectrometry in monitoring the extent and distribution of glycation

A combination of chromatographic and mass spectrometric techniques was used to evaluate the extent and distribution of glycation within the glycated hemoglobin (GHb) molecule. Studies on quantification of hemoglobin (Hb) glycation by electrospray ionization mass spectrometry (ES-MS) of intact globins employed specimens from 10 diabetic individuals and five normal controls. Detailed structural analysis of the phenylboronate affinity chromatography/ion-exchange (IE) HPLC-separated sub-populations of GHb was performed on a specimen carrying 13.7% GHb. An efficient protocol for mapping glycation sites within alpha and beta globins was developed, e.g., Glu-C/Asp-N proteolytic digestion followed by LC-ES-MS. Relative site occupancy within discrete components of GHb was evaluated. A correlation between the degree of glycation measured at Hb level (by affinity chromatography) and at globin level (measured by ES-MS) was carried out. The above studies led us to conclude that during the process of phenylboronate chromatography GHb dimers, rather than tetramers, are bound to the affinity resin so a fraction of glycated dimers rather than tetramers is measured. This finding implies that a process of glycation affects a much higher number of native Hb tetramers than was previously contemplated. No glycation sites appear to be missed by phenylboronate affinity chromatography. We have found no evidence of the presence of multiple glycations within a single globin chain. While glycation of both globins within a dimer cannot be excluded, it is unlikely to be a significant phenomenon. According to ES-MS data, an equivalent of about one globin per alphabeta dimer of the affinity chromatography-isolated GHb carried glycation.

Social disadvantage and variation in the incidence of end-stage renal disease in Australian capital cities

OBJECTIVE

To evaluate variation in the incidence of end-stage renal disease (ESRD) within Australian capital cities. To explore the relation between the incidence of ESRD and socioeconomic disadvantage.

METHODS

We obtained data from the Australian and New Zealand Dialysis and Transplant Registry (ANZDATA) regarding 5,013 patients from capital cities who started ESRD treatment between 1 April 1993 and 31 December 1998. We used the postcode at the start of treatment to calculate the average annual incidence of ESRD for each of 51 capital city regions using 1996 Census counts based on place of usual residence. We calculated standardised incidence ratios with 95% confidence intervals for each region. The standardised incidence ratios were examined in relation to the SEIFA Index of Relative Socio-economic Disadvantage (IRSD), derived from the 1996 Census. Low IRSD values indicate more disadvantaged areas.

RESULTS

There is significant variation in the standardised incidence of ESRD within capital cities. There was a significant correlation (r=-0.41, p=0.003) between the standardised incidence ratio for ESRD and the SEIFA IRSD.

CONCLUSIONS AND IMPLICATIONS

Capital city areas that are more disadvantaged have a higher incidence of ESRD. Socioeconomic factors may be important determinants of the risk of developing ESRD.

Glove reinforcement: an alternative to double gloving

Gloves, worn by the surgical team to prevent transmission of infections from and to patients, are prone to tears and perforations. This study was done to determine the frequency and sites of unrecognized glove perforation during surgical procedures. The percentage of glove perforation was 14%. Of the punctures, 73% occurred in one of four contiguous locations on the glove. We recommend glove reinforcement at these locations to provide better protection, as well as to reduce the burden of double gloving.

Convection-enhanced delivery of AAV-2 combined with heparin increases TK gene transfer in the rat brain

Adeno-associated virus type2 (AAV-2) binds to heparan-sulfate proteoglycans on the cell surface. In vivo, attachment of viral particles to cells adjacent to the injection tract limits the distribution of AAV-2 when infused into the CNS parenchyma and heparin co-infusion might decrease the binding of AAV-2 particles to cells in the vicinity of the infusion tract. We have previously shown that heparin co-infusion combined with convection enhanced delivery enhances distribution of the GDNF family trophic factors (heparin-binding proteins) in the rat brain. In this work we show that heparin co-infusion significantly increases the volume of distribution of AAV-2 as demonstrated by immunoreactivity to the transgene product 6 days after infusion into the rat striatum.

Regional variation in the incidence of end-stage renal disease in Indigenous Australians

OBJECTIVE

To evaluate regional variation in the incidence of end-stage renal disease (ESRD) in Indigenous Australians, and to examine the proximity to ESRD treatment facilities of Indigenous patients.

DESIGN

Secondary data review, with collection of primary data regarding patients' place of residence before beginning ESRD treatment.

PARTICIPANTS

Indigenous ESRD patients who commenced treatment in Australia during 1993-1998.

METHODS

We obtained data from the Australian and New Zealand Dialysis and Transplant Registry regarding 719 Indigenous patients who started ESRD treatment between 1 January 1993 and 31 December 1998. We obtained primary data from the treating renal units to determine the place of residence before beginning renal replacement therapy. We calculated the average annual incidence of ESRD for each of the 36 Aboriginal and Torres Strait Islander Commission regions using population estimates based on the 1996 Census, and calculated standardised incidence ratios with 95% confidence intervals for each region. We compared the number of cases with the treatment facilities available in each region.

MAIN OUTCOME MEASURE

Regional standardised ESRD incidence for Indigenous Australians referenced to the total resident population of Australia.

RESULTS

Standardised ESRD incidence among Indigenous Australians is highest in remote regions, where it is up to 30 times the national incidence for all Australians. In urban regions the standardised incidence is much lower, but remains significantly higher than the national incidence. Forty-eight per cent of Indigenous ESRD patients come from regions without dialysis or transplant facilities and 16.3% from regions with only satellite dialysis facilities.

CONCLUSIONS

There is marked regional variation in the incidence of ESRD among Indigenous Australians. Because of the location of treatment centres, there is inequitable access to ESRD treatment services for a significant proportion of Indigenous patients.

Long-term habituation of the speech-elicited mismatch negativity

A significant issue in the use of the mismatch negativity evoked potential (MMN) concerns its low signal-to-noise ratio (SNR). One can improve the noise level by increasing the number of samples included in the averaged response. However, improvement achieved in this way assumes that the signal, the MMN, remains stable for extended test times, an assumption which has not been tested. If the MMN is not stable, or exhibits habituation over the test session, then SNR would be adversely affected. MMN response magnitude was measured in 5-min intervals over the course of a test session in response to various speech syllable contrasts. Significant long-term habituation of MMN was observed for all three subject populations tested: young adults, school-age children, and guinea pigs. The time course of the habituation and the stimulus conditions under which it occurs have important implications for research and clinical applications of the MMN. Recording procedures that minimize habituation effects may be used to advantage to improve the signal-to-noise ratio of the MMN.

Echoviruses 1 and 8 are closely related genetically, and bind to similar determinants within the VLA-2 I domain

Echoviruses (EV) 1 and 8 were originally considered to be distinct serotypes, but more recently have been considered strains of the same virus. In experiments with chimeric recombinant fusion proteins, both viruses bound to the I domain of the integrin VLA-2, and both required the same receptor residues for attachment. A full-length, infectious cDNA clone encoding EV1 was obtained; its nucleotide sequence was determined, as were the sequences encoding the EV8 capsid. EV1 and 8 show 94% amino acid identity within the capsid region and are more similar to each other than to any other human picornavirus.

Neurobiologic responses to speech in noise in children with learning problems: deficits and strategies for improvement

OBJECTIVES

Some children with learning problems (LP) experience speech-sound perception deficits that worsen in background noise. The first goal was to determine whether these impairments are associated with abnormal neurophysiologic representation of speech features in noise reflected at brain-stem and cortical levels. The second goal was to examine the perceptual and neurophysiological benefits provided to an impaired system by acoustic cue enhancements.

METHODS

Behavioral speech perception measures (just noticeable difference scores), auditory brain-stem responses, frequency-following responses and cortical-evoked potentials (P1, N1, P1', N1') were studied in a group of LP children and compared to responses in normal children.

RESULTS

We report abnormalities in the fundamental sensory representation of sound at brain-stem and cortical levels in the LP children when speech sounds were presented in noise, but not in quiet. Specifically, the neurophysiologic responses from these LP children displayed a different spectral pattern and lacked precision in the neural representation of key stimulus features. Cue enhancement benefited both behavioral and neurophysiological responses.

CONCLUSIONS

Overall, these findings contribute to our understanding of the preconscious biological processes underlying perception deficits and may assist in the design of effective intervention strategies.

Hypercalcemia and human nature

Patients on hemodialysis may develop severe and symptomatic hypercalcemia if skeletal buffering is ineffective. We report a case of persistent hypercalcemia with apparent extrarenal vitamin D synthesis. Associated aluminium intoxication was suggested on desferrioxamine challenge and adynamic uremic osteodystrophy confirmed on bone biopsy. Plasma calcitriol did not suppress with corticosteroids but did with ketoconazole. No other evidence for underlying granulomatous disease was found. We discuss our approach to less usual causes of hypercalcemia, and emphasise the pitfalls associated with factitious disorders.

Ultrasonography incorrectly diagnoses gallbladder polyps

To determine the accuracy of ultrasound-diagnosed polypoid lesions of the gallbladder in their institution, the authors reviewed the records of 41 patients with polypoid lesions of the gallbladder who underwent cholecystectomy, and collected data concerning age, sex, symptoms, and histopathologic diagnosis. Histopathologic evaluation confirmed polyps in only two patients (4.9%) categorized as having polypoid lesions of the gallbladder. Most specimens from patients with ultrasonography reports suggesting small polyps manifested cholesterolosis (17 of 41) or cholelithiasis (15 of 41). No specimen harbored malignancy. Mean patient age was 47.4 years, and the most common symptoms were pain (85%), nausea (44%), vomiting (29%), and abnormal liver function test results (14%). The accuracy of sonography for diagnosing polypoid lesions of the gallbladder was poor. Many of the small polyps seen on sonography most likely represented a stone embedded in the gallbladder wall or other abnormality. Because of the likelihood of cholelithiasis, the authors recommend that patients with biliary symptoms and ultrasonography findings suggesting polypoid lesions of the gallbladder undergo cholecystectomy.

Erythroid Kruppel-like factor (EKLF) coordinates erythroid cell proliferation and hemoglobinization in cell lines derived from EKLF null mice

Erythroid Kruppel-like factor (EKLF) is a transcription factor of the C2H2 zinc-finger class that is essential for definitive erythropoiesis. We generated immortal erythroid cell lines from EKLF(-/-) fetal liver progenitor cells that harbor a single copy of the entire human beta-globin locus and then reintroduced EKLF as a tamoxifen-inducible, EKLF-mutant estrogen receptor (EKLF-ER) fusion protein. Addition of tamoxifen resulted in enhanced differentiation and hemoglobinization, coupled with reduced proliferation. Human beta-globin gene expression increased significantly, whereas gamma-globin transcripts remained elevated at levels close to endogenous mouse alpha-globin transcript levels. We conclude that EKLF plays a role in regulation of the cell cycle and hemoglobinization in addition to its role in beta-globin gene expression. The cell lines we used will facilitate structural and functional analyses of EKLF in these processes and provide useful tools for the elucidation of nonglobin EKLF target genes.

Nonresponse in a follow-up to a representative telephone survey of adult drinkers

OBJECTIVE

Examined predictors of nonresponse among respondents who agreed to receive a follow-up questionnaire on alcohol use after participating in a representative telephone survey, and among respondents who did and did not return the follow-up questionnaire.

METHOD

A total of 2,072 (52.2% female) respondents to a representative monthly telephone survey were assessed on sociodemographic variables and alcohol use. Respondents were asked whether they would be willing to fill out an additional mailed questionnaire on alcohol use and attitudes toward drinking. Almost half (n = 956; 46%) of respondents agreed to participate in the follow-up survey; 430 (45%) of those individuals completed and returned the questionnaire.

RESULTS

Agreement to receive the follow-up questionnaire was unrelated to alcohol use. Regarding gender, men were 1.42 times more likely than women to exhibit nonresponse in returning the follow-up questionnaire (95% CI: 1.08-1.42). After adjusting for the impact of demographic factors, respondents who consumed alcohol at least once per week were 1.43 times more likely than respondents who drank less frequently to exhibit nonresponse in returning the questionnaire (95% CI: 1.05-1.93). Respondents who consumed five or more standard drinks at least once per week were 1.83 times more likely to exhibit nonresponse in returning the questionnaire, compared with respondents who engaged in heavy drinking less frequently (95% CI: 1.15-2.92).

CONCLUSIONS

Mailout questionnaires following a representative telephone survey may bias samples toward obtaining fewer men, fewer weekly drinkers and fewer heavier drinkers. Although the magnitude of these biases were relatively small, epidemiological studies on alcohol use may wish to oversample men and heavier drinkers in follow-up studies recruiting from population surveys.

Successful unrelated donor bone marrow transplantation for paroxysmal nocturnal hemoglobinuria

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired clonal disease of hematopoiesis due to a mutation in the PIG-A gene. Affected patients may demonstrate hemolysis or venous thrombosis, and may develop MDS or aplastic anemia. Successful results may be obtained after conditioning and transplantation from syngeneic or genotypically matched sibling donors. Experience with transplantation from matched unrelated donors (MUD) is limited to eight patients, with only one survivor. We report three patients who underwent successful MUD BMT for PNH. All three patients had severe aplastic anemia (SAA) and PNH at the time of BMT. Unrelated donors were six-antigen HLA-matched (n = 2) or HLA-A mismatched (n = 1). Conditioning consisted of cytarabine, cyclophosphamide, TBI, and ATG. Grafts were T cell-depleted by anti-CD6/CD8 antibodies + complement. Further GVHD prophylaxis consisted of cyclosporine. Patients received 0.7-1.1 x 10(8) nucleated cells/kg and 1.1-2.1 x 10(6) CD34(+) cells/kg. Neutrophil engraftment occurred at 16-21 days. One patient developed grade 1 acute GVHD. Although all three patients experienced significant transplant-related complications, they ultimately resolved and all patients are alive and well 30-62 months after BMT. T cell-depleted MUD BMT is an effective treatment option for PNH-related MDS and SAA.

Perceived vulnerability to alcohol-related harm in young adults: independent effects of risky alcohol use and drinking motives

Perceived vulnerability to negative outcomes can motivate heavy drinkers to adopt health-protective behavior, but little is known about determinants of perceived vulnerability to alcohol-related harm. University students (N = 286) were assessed to determine epidemiological risk status on a standardized problem drinking measure, typical reasons for drinking and cutting down, and perceived risk of experiencing alcohol-related harm. Results showed a positive relationship between problem drinking status and perceived risk of experiencing harm. However, at-risk drinkers believed that they were less likely to personally experience harm than comparable peers (p < .001), whereas not-at-risk drinkers showed no self-other differences in perceived vulnerability. Drinking motives significantly improved the prediction of perceived vulnerability when epidemiological risk status was controlled. Perceived vulnerability to alcohol-related harm is affected by problem drinking status and (independently) by the psychological functions that drinking serves.

Psychosocial determinants of perceived vulnerability to harm among adult drinkers

OBJECTIVE

Perceived vulnerability to harm is widely acknowledged as a determinant of behavior change, but little is known about why some drinkers believe that they are personally "at risk" for problems while others do not. This study examined perceived vulnerability to alcohol-related harm in relation to epidemiological risk status on a standardized problem-drinking measure and two psychosocial measures of drinking context: (1) typical reasons for drinking and cutting down and (2) social network influences related to alcohol use. We evaluated the general hypothesis that these psychosocial variables would independently affect perceived vulnerability to alcohol-related harm, over and above epidemiological risk status.

METHOD

Adults between the ages of 18 and 79 (N = 430; 249 women, 173 men, 8 gender unknown) completed a questionnaire about drinking behavior and drinking-related social and motivational context.

RESULTS

There was a positive relationship between problem-drinking status and perceived risk of experiencing harm, and no support for the idea that objectively "at-risk" drinkers believe that they are less likely to personally experience harm than comparable peers. Drinking motives and social network variables each significantly improved the prediction of perceived vulnerability when epidemiological risk status was controlled.

CONCLUSIONS

Interventions designed to alter drinkers' risk perceptions should take into account the reasons that people have for drinking and the social network context of alcohol use, in addition to whether or not individuals are "problem drinkers."

Interest in different forms of self-help in a general population sample of drinkers

The study investigates: (1) the level of interest in self-help services for drinkers, and (2) the predictors of interest in these services. A representative sample of 1,557 Ontario respondents participated in a telephone survey. Current drinkers (n=1,247) were asked about their interest in getting: (a) a telephone call from a therapist to help them evaluate their drinking, (b) a self-help book, and (c) a computerized summary comparing their drinking to that of other Canadians. Bivariate comparisons of demographic and drinking-related variables were made between those interested and not interested in each of the offered services. Logistic regression analysis was used to find the best predictors of interest. The results revealed that 16% were interested in a telephone call, 26% in a self-help book, and 39% in computerized normative feedback. Negative consequences of drinking and indicators of lower societal resources increased interest in self-help services. Computerized feedback and self-help books serve as cheap and nonintrusive ways to provide incentive for change to early-stage problem drinkers due to the interest they raise in the intended target population.

Potent suppression of the parathyroid glands by hydroxylated metabolites of dihydrotachysterol(2)

BACKGROUND

Dihydrotachysterol(2), a licensed pharmaceutical, is hydroxylated to 25-hydroxydihydrotachysterol(2) (25(OH)DHT(2)) and 1 alpha,25-dihydroxydihydrotachysterol(2) (1 alpha,25(OH)(2)DHT(2)) in man. We have compared the biological activity of these metabolites with calcitriol and the 'non-calcaemic' analogue, 22-oxacalcitriol (OCT) in bovine parathyroid cell cultures and in rats.

METHODS

The effect of each sterol on parathyroid hormone (PTH) secreted by primary bovine parathyroid cells was measured. High-performance liquid chromotography and gas chromotography-mass spectrometry were used to investigate in vitro 25(OH)DHT(2) metabolism. Rats were given a single intraperitoneal injection or five daily injections of each sterol, and changes in ionized calcium and PTH were measured.

RESULTS

In vitro, all sterols suppressed PTH significantly. Calcitriol and OCT were of similar potency, but 1 alpha, 25(OH)(2)DHT(2) and 25(OH)DHT(2) required higher concentrations to suppress PTH equally. We were unable to detect metabolism of 25(OH)DHT(2) to 1 alpha,25(OH)(2)DHT(2) in vitro. In rats, a single dose of 0.5 microg/rat of calcitriol increased ionized calcium at 30 and 40 h (statistically significant at 48 h). 50 microg of OCT and 1 alpha,25(OH)(2)DHT(2) did not cause significant hypercalcaemia at 48 h, although 1 alpha,25(OH)(2)DHT(2) caused hypercalcaemia at 30 h. In contrast, 50 microg of 25(OH)DHT(2) caused hypercalcaemia at 48 h but not at 30 h. Five daily doses of 0.001 microg/rat of calcitriol caused a significant rise in calcium and a 50% fall in PTH. OCT and 1 alpha,25(OH)(2)DHT(2) at 0.025 and 0.5 microg/rat respectively caused similar suppression of PTH but without hypercalcaemia.

CONCLUSION

1 alpha,25(OH)(2)DHT(2) and 25(OH)DHT(2) are potent suppressors of PTH in vitro and in vivo. 25(OH)DHT(2) may be active by virtue of its pseudo-1 alpha-hydroxyl group. Hypercalcaemia caused by a single dose of 1 alpha,25(OH)(2)DHT(2) appeared to be more transient than calcitriol. Five daily doses of 1 alpha, 25(OH)(2)DHT(2) and OCT could achieve 50% suppression of PTH without significant increments in ionized calcium. In contrast, suppression of PTH by calcitriol was associated with significant increments in ionized calcium. These data suggest that like OCT, 1 alpha, 25(OH)(2)DHT(2) can dissociate calcaemic actions from parathyroid-suppressing actions in a manner that may be therapeutically useful.

Speech-evoked neurophysiologic responses in children with learning problems: development and behavioral correlates of perception

OBJECTIVES

To evaluate the maturational progression of speech-evoked P1/N1/N2 cortical responses over the life span, determine whether responses are distinctive in clinical populations experiencing learning problems and elucidate the functional significance of these responses.

DESIGN

The P1/N1/N2 complex was measured in 150 normal subjects (5 to 78 yr) and 86 subjects with learning problems (LP) (8 to 15 yr) to a synthetic CV syllable. Analyses included description and comparison of the developmental time course in both groups and evaluation of the relationship between P1/N1/N2 and children's performance on speech discrimination tasks and standardized learning measures.

RESULTS

Findings revealed significant changes in waveform morphology, latency and amplitude as a function of age. Maturational patterns in the group of children with learning problems did not differ from the normal group. P1/N1/N2 parameters were significantly correlated with standardized tests of Spelling, Auditory Processing and Listening Comprehension in the LP group. Moreover, there was a predictive relationship between Auditory Processing and N2 latency.

CONCLUSIONS

The P1/N1/N2 complex changes throughout life from school-age to old age. The developmental sequence throughout the school-age years is similar in normal and LP children. Thus, differences in the rate of P1/Nl/N2 latency and amplitude development do not appear to be distinctive in these two populations. The relationship between P1/N1/N2 parameters and standardized measures of learning (particularly between Auditory Processing and N2 latency) provides new information about the role of these responses in hearing and highlights the potential value in characterizing auditory processing deficits.

Are parathyroidectomies still appropriate in chronic dialysis patients?

The uremic milieu generates chronic stimulatory input to the parathyroid glands, which is mediated principally by low calcium, high phosphate and low calcitriol, and results in increased parathyroid hormone (PTH) synthesis and release and an increase in parathyroid mitotic activity with the development of monoclonal areas of nodular hyperplasia. Such glands do not fully express the machinery required to mediate the suppressive inputs to the parathyroids; the extracellular calcium receptor (CaR) and the vitamin D receptor (VDR) are both downregulated. In most of these patients ablation, by parathyroidectomy or ethanol injection, provides the only means of correcting the hyperparathyroidism; apoptosis in parathyroid cells is negligible and clinically irrelevant. In practice, surgery is often delayed by a doomed and ultimately futile attempt to effect control by medical means. Better predictors of the likely success or failure of optimal non surgical management are needed. Gland size exceeding 1 cm3 and elevated PTH despite hypercalcemia (implying loss of suppressibility by calcium), in the presence of good phosphate control and adequate calcitriol provision point strongly to eventual failure of medical treatment and the need for parathyroid ablation. Parathyroidectomy, usually subtotal, remains the standard management, with ultrasound guided injection of ethanol or calcitriol showing promise in some centers. The above scenario is unlikely to be changed greatly by the new emerging vitamin D metabolites, but calcimimetic agents may well increase the scope of non surgical management.

Distribution of AAV-TK following intracranial convection-enhanced delivery into rats

Adeno-associated virus (AAV)-based vectors are being tested in animal models as viable treatments for glioma and neurodegenerative disease and could potentially be employed to target a variety of central nervous system disorders. The relationship between dose of injected vector and its resulting distribution in brain tissue has not been previously reported nor has the most efficient method of delivery been determined. Here we report that convection-enhanced delivery (CED) of 2.5 x 10(8), 2.5 x 10(9), or 2.5 x 10(10) particles of AAV-thymidine kinase (AAV-TK) into rat brain revealed a clear dose response. In the high-dose group, a volume of 300 mm3 of brain tissue was partially transduced. Results showed that infusion pump and subcutaneous osmotic pumps were both capable of delivering vector via CED and that total particle number was the most important determining factor in obtaining efficient expression. Results further showed differences in histopathology between the delivery groups. While administration of vector using infusion pump had relatively benign effects, the use of osmotic pumps resulted in notable toxicity to the surrounding brain tissue. To determine tissue distribution of vector following intracranial delivery, PCR analysis was performed on tissues from rats that received high doses of AAV-TK. Three weeks following CED, vector could be detected in both hemispheres of the brain, spinal cord, spleen, and kidney.

Convection-enhanced delivery of AAV vector in parkinsonian monkeys; in vivo detection of gene expression and restoration of dopaminergic function using pro-drug approach

Using an approach that combines gene therapy with aromatic l-amino acid decarboxylase (AADC) gene and a pro-drug (l-dopa), dopamine, the neurotransmitter involved in Parkinson's disease, can be synthesized and regulated. Striatal neurons infected with the AADC gene by an adeno-associated viral vector can convert peripheral l-dopa to dopamine and may therefore provide a buffer for unmetabolized l-dopa. This approach to treating Parkinson's disease may reduce the need for l-dopa/carbidopa, thus providing a better clinical response with fewer side effects. In addition, the imbalance in dopamine production between the nigrostriatal and mesolimbic dopaminergic systems can be corrected by using AADC gene delivery to the striatum. We have also demonstrated that a fundamental obstacle in the gene therapy approach to the central nervous system, i.e., the ability to deliver viral vectors in sufficient quantities to the whole brain, can be overcome by using convection-enhanced delivery. Finally, this study demonstrates that positron emission tomography and the AADC tracer, 6-[(18)F]fluoro-l-m-tyrosine, can be used to monitor gene therapy in vivo. Our therapeutic approach has the potential to restore dopamine production, even late in the disease process, at levels that can be maintained during continued nigrostriatal degeneration.