Temporal and sequential negative priming generalise across visual and auditory modalities and are dependent on relative rather than absolute speed

Prior work has found a negative priming effect for a sequence, and more purely time-based negative priming has also been identified. Although sequential effects have been reported with both visual and auditory stimuli, only visual stimuli have been used in experiments examining purely temporal negative priming. In this article, sequential and temporal negative priming are compared across modalities. Prime trials included random presentation of a target (auditory bird chirp or visual X), a non-target (auditory dog bark or visual O), and two neutral stimuli (auditory computer beeps or empty visual boxes). Probe trials included random presentation of the target and three neutral stimuli. Participants indicated the temporal location of the target. On 88% of the trials, participants (N = 119 in Experiment 1; N = 65 in Experiment 2) indicated the location of the non-target stimulus from the prime trial. Results showed an increase in response time when the temporal location of the probe's target was the same as the location of the non-target stimulus from the prime trial, but this only occurred when the prime was presented more slowly. Experiment 2 tested, and falsified, the hypothesis that a fixed amount of time on the prime is necessary to bind features of the non-target stimulus with temporal and sequential positions. Together, these data show that sequential and temporal negative priming effects generalise across modality and that relative rather than fixed timing is critical. Implications for theories of negative priming are discussed.

Susceptibility to nontuberculous mycobacterial lung disease

The nontuberculous mycobacteria (NTM) exhibit heterogeneous pathogenicity in humans. Articles on known and potential human factors capable of producing susceptibility to NTM lung disease (NTMLD) were identified by a systematic search of the medical literature, and are reviewed in the present study. Patients with pre-existing structural lung disease are known to be at risk of NTMLD. Other susceptible groups have become recognised since the 1980s, in particular middle-aged nonsmokers without previous lung disease (a group including those with Lady Windermere syndrome) and patients with genetically determined defects of cell-mediated immunity, including abnormalities of the interleukin-12/interferon-gamma axis, certain human leukocyte antigen alleles, cystic fibrosis transmembrane conductance regulator mutations, and polymorphisms of solute carrier 11A1 (or natural resistance-associated macrophage protein 1) and the vitamin D receptor. Information is also accruing about acquired systemic causes of susceptibility to NTMLD, including inhibitory antibodies directed against interferon-gamma, post-menopausal waning of endogenous oestrogen levels, coeliac disease and exposure to use of dietary phyto-oestrogens. It is not known whether immunosuppressive factors, such as oral corticosteroid treatment, chronic renal failure, diabetes mellitus and other known risk factors for pulmonary tuberculosis, are also risk factors for the development of NTMLD. Caution is appropriate in managing such patients.

New recommendations for duration of respiratory isolation based on time to detect Mycobacterium tuberculosis in liquid culture

It was hypothesised that the time to detect Mycobacterium tuberculosis in liquid culture of sputum from patients with pulmonary tuberculosis may be a better indicator for the duration of respiratory isolation than sputum smear status. Pre-treatment and during-treatment sputum acid-fast bacilli (AFB) smear and culture results were reviewed in 284 patients with pulmonary tuberculosis. The time to detect M. tuberculosis in liquid culture (TTD-TB) was the number of days from inoculation of the Mycobacterial Growth Indicator Tube to culture detection and visualisation of AFB. The median (interquartile range) TTD-TB for smear group 0 (no bacilli seen) was 14 (12-20) days. This value was used as the standard at which release from isolation could be permitted. In smear group 4 (>9 AFB per high-power field (hpf) in sputum specimens before treatment) patients, the TTD-TB exceeded 14 days after a median of 25 days of treatment. The current authors recommend that patients in smear groups 1 and 2 (1-9 AFB per 100 hpf and 1-9 AFB per 10 hpf in sputum specimens before treatment, respectively) receive treatment in respiratory isolation for 7 days, provided the risk of drug resistance is low. Smear group 3 (1-9 AFB per hpf) and 4 patients should receive treatment in respiratory isolation for 14 and 25 days, respectively. These criteria would have reduced the duration of respiratory isolation by 1,516 days in the 143 study participants with sputum smear-positive pulmonary tuberculosis. Provided clinical and radiographical criteria are satisfactory, use of the time to detect Mycobacterium tuberculosis in liquid culture could enable the duration of respiratory isolation to be predicted from the pre-treatment sputum smear grade. The recommendations enable isolation to end well before sputum becomes smear negative, with considerable benefits to patients and healthcare providers.

Induced sputum and bronchoscopy in the diagnosis of pulmonary tuberculosis

BACKGROUND

Previous studies suggest that bronchoscopy and a single induced sputum sample are equally effective for diagnosing pulmonary tuberculosis.

METHODS

In a prospective study of subjects with possibly active pulmonary tuberculosis, the diagnostic yield of three induced sputum tests was compared with that of bronchoscopy. Subjects either produced no sputum or (acid fast) smear negative sputum. Bronchoscopy was only performed if at least two induced sputum samples were smear negative.

RESULTS

Of 129 subjects who completed all tests, 27 (21%) had smear negative and culture positive specimens, 14 (52%) on bronchoscopy and 26 (96%) on induced sputum (p<0.005). One patient was culture positive on bronchoscopy alone compared with 13 on induced sputum alone; 13 were culture positive on both tests. Induced sputum positivity was strikingly more prevalent when chest radiographic appearances showed any features of active tuberculosis (20/63, 32%) than when appearances suggested inactivity (1/44, 2%; p<0.005). Induced sputum costs were about one third those of bronchoscopy, and the ratio of costs of the two tests per case of tuberculosis diagnosed could be as much as 1:6.

CONCLUSIONS

In subjects investigated for possibly active or inactive tuberculosis who produce no sputum or have smear negative sputum, the most cost effective strategy is to perform three induced sputum tests without bronchoscopy. Induced sputum testing carries a high risk of nosocomial tuberculosis unless performed in respiratory isolation conditions. The cost benefits shown could be lost if risk management measures are not observed.

Studies of L-arginine transport in bovine aortic endothelial cells

We have previously demonstrated that p(1),p(4)-diadenosine 5'-tetraphosphate induces the release of NO and modulates the uptake of L-arginine by bovine aortic endothelial cells (BAEC) [Hilderman, R. H., and Christensen, E. F. (1998) FEBS Lett. 407, 320-324; Hilderman, R. H., Casey, T. E., and Pojoga, L. H. (2000) Arch. Biochem. Biophys. 375, 124-130]. In this communication we characterize the uptake of L-Arg by BAEC. L-Arg is transported into BAEC by at least two different transporter systems. One transporter system is protein synthesis dependent, and L-Arg transported by this system is incorporated into proteins. The second transporter system involved in L-Arg uptake is protein synthesis independent, and uptake occurs by facilitated diffusion. The L-Arg transported by facilitated diffusion is metabolized into L-argininosuccinate. Homologous and heterologous competition uptake studies were performed using a fixed concentration of radiolabeled L-Arg, L-lysine, and L-leucine with varying concentrations of competing nonradiolabeled amino acids. The results of these competition uptake studies are consistent with the protein-synthesis-dependent uptake of L-Arg taking place through a transporter system that is highly specific for L-Arg and with the facilitated diffusion uptake taking place through a transporter that is specific for L-Arg and L-Leu.

Evaluation of the tuberculin gamma interferon assay: potential to replace the Mantoux skin test

We evaluated an in vitro test of cell-mediated immunity, the tuberculin gamma interferon assay, QuantiFERON-TB (QIFN), in 455 individuals from three groups: group I, 237 immigrants from high-risk countries; group II, 127 health care workers undergoing Mantoux testing; group III, 91 patients being investigated for possible active tuberculosis (79 patients) or Mycobacterium avium-Mycobacterium intracellulare complex infection (12 patients). The QIFN results were compared either to those of the Mantoux test or to microbiological and clinical diagnosis, as appropriate. In each group the correlation between the diameter of induration for the skin test and the magnitude of QIFN response was significant and of moderate strength (Spearman's rank correlation coefficient; rho = 0.59 to 0.61; P < 0.001). For group I, the agreement between QIFN and Mantoux results was 89% for Mantoux-negative and 64% for Mantoux-positive individuals. For group II, when >/=10-mm-diameter induration was taken as positive, the agreement was 81% for Mantoux-negative and 67% for Mantoux-positive individuals. For group III, agreement was 81% for Mantoux-negative and 86% for Mantoux-positive patients. For patients being evaluated for active tuberculosis, the performance of the Mantoux test was not statistically different from that of the QIFN assay. In patients with active tuberculosis, the assay had a sensitivity of 77%, not significantly higher for extrapulmonary than pulmonary cases (83% versus 74%). QIFN sensitivity was not significantly different for smear-negative or smear-positive cases (80% versus 71%). The QIFN assay is a potential replacement for the Mantoux test. The acceptability of these performance values and those of similar evaluations will determine the place this test will have in detecting evidence of mycobacterial infection.

Mycobacterial cervical adenitis in Auckland: diagnosis by fine needle aspirate

AIMS

To evaluate the role of fine needle aspiration (FNA) in the diagnosis of tuberculous and non-tuberculous mycobacterial cervical adenitis in Auckland, and to examine the demography of these conditions.

METHOD

We reviewed the medical records of cases of mycobacterial adenitis in the Auckland region between 1991-1994. Cases were identified by cross-checking the reference mycobacteriology laboratory records, all hospital cytology reports from cases who had an FNA taken from the neck region and hospital discharge diagnosis databases.

RESULTS

Twenty-two cases of M tuberculosis adenitis, and 13 of M avium adenitis were identified. No FNAs were smear positive for mycobacteria. The FNA from 6/18 (33%) cases of M tuberculosis adenitis and from 4/6 (66%) M avium adenitis cases were culture positive. Bacteriological confirmation was obtained (by various methods) in 72% of tuberculous and in 100% of M avium adenitis cases. The clinical picture was different for the two organisms: tuberculous adenitis occurred mainly in caucasian adults, while M avium adenitis cases were predominantly caucasian children. None of the confirmed cases of tuberculous adenitis demonstrated drug resistance to standard anti-tuberculous agents.

CONCLUSIONS

(1) Clinicians should more consistently include mycobacterial tests when investigating neck lumps. (2) FNA is not a reliable diagnostic test for mycobacterial cervical adenitis in New Zealand. Here, FNA should only be regarded as a screening test for mycobacterial adenitis. If anti-tuberculous treatment is required before it is known whether FNA has provided a positive culture, excision biopsy should first be performed to identify the mycobacterium and its susceptibility pattern.

Ocular toxicity from ethambutol: a review of four cases and recommended precautions

AIMS

To document the clinical and demographic features of cases of ethambutol ocular toxicity, to review the literature on this subject and to critically review current guidelines for ethambutol administration.

METHODS

Cases of ocular toxicity from ethambutol were sought retrospectively at Green Lane and Wellington Hospitals between 1992 and 1995. The records of cases identified were examined.

RESULTS

Four subjects with tuberculosis developed ocular toxicity 2 1/2, 7 1/2, 8 and 12 months after starting ethambutol. Normal visual acuity returned in three cases; one patient has severe, permanent visual impairment. Language difficulties were present in three subjects.

CONCLUSIONS

Impaired communication was potentially very important in this series. Special care is needed in educating patients about ethambutol. We propose additional recommendations: 1. the usual daily dose of ethambutol should be 15 mg/kg/day, not 25 mg/kg/day; using 25 mg/kg/day (or lesser doses in the presence of renal impairment) should prompt regular formal ophthalmological evaluation (e.g. monthly) in cases with comprehension or communication difficulties; 3. both ethambutol and isoniazid should be stopped immediately if severe optic neuritis occurs. Isoniazid should be stopped if less severe optic neuritis does not improve within six weeks after stopping ethambutol.

Automated 96-well solid phase extraction for the determination of doramectin in cattle plasma

Automated standard and sample preparation have been coupled with 96-well solid phase extraction (SPE) technology to produce a cost effective, high throughput system for the analysis of drugs in biological media. The system was originally designed using the Packard Multiprobe 104DT robotic sample processor (RSP) to improve throughput for the assay of doramectin in cattle plasma, and the assay has since been validated (0.5-100 ng ml[-1]) using the Tecan Genesis RSP 150/8. The robotic processor conducts all liquid handling procedures involved in sample extraction. These comprise preparation of calibration standards in plasma, dispensing and diluting of plasma samples and addition of internal standard. In addition, the robot primes the 96-well SPE block, applies calibration standards and samples, draws the mixtures through the 96-well SPE block, and finally washes the block ready for manual elution. The doramectin assay involves high-performance liquid chromatography (HPLC) with fluorescence detection, and requires the sample extracts to be derivatised prior to analysis. The derivatisation procedure is performed manually in situ in the polypropylene deep 96-well block into which the samples have been eluted from the SPE-block. The derivatised samples are taken directly from the deep well block and injected into the HPLC for analysis. This type of batch processing keeps sample transfer to a minimum. Automated sample preparation, in combination with the use of 96-well technology, has reduced both cost and effort required in the analysis of doramectin in cattle plasma samples, and has resulted in improved sample throughput.

Multidrug resistant tuberculosis in Auckland 1988-95

AIMS

To review all cases of multidrug resistant tuberculosis (MDRTb) in Auckland between 1988-95; and to look for ways in which the diagnosis and management may be improved.

METHODS

Cases of multidrug resistant tuberculosis were identified from Green Lane Hospital tuberculosis laboratory records. Clinical details were obtained from hospital case records, and radiographs were reviewed.

RESULTS

Nine of the 838 (1.1%) confirmed cases of tuberculosis had multidrug resistant tuberculosis. Eight were foreign-born and four had previously been treated for tuberculosis. Three patients underwent thoracic surgery. Two patients died and one was not treated, No relapses have occurred. Potential to improve on the treatment given was evident in retrospect in three patients.

CONCLUSIONS

Assessment of risk factors for multidrug resistant tuberculosis and early transfer of specimens to a tuberculosis reference laboratory are required to enable multidrug resistance to be identified early. Extensive disease, drug side effects and coexistent medical problems make MDRTb very difficult to cure. Directly observed therapy is recommended for multidrug resistant tuberculosis cases and is underutilised in Auckland.

Role of hepatic metabolism in the bioactivation and detoxication of amodiaquine

1. The hepatic metabolism of the antimalarial drug amodiaquine was investigated in order to gain further insight into the postulated metabolic causation of the hepatotoxicity, which restricts the use of the drug. After intraportal (i.p.) administration (54 mumol/kg) to the anaesthetized rat, the drug was excreted in bile (23 +/- 3% dose over 5 h; mean +/- SD, n = 6) primarily as thioether conjugates. 2. After i.p. administration, 20% of the dose was excreted into urine over 24 h as parent compound and products of N-dealkylation and oxidative deamination. Desethylamodiaquine accumulated in liver, but was not a substrate for bioactivation as measured by biliary elimination of a glutathione adduct. 3. Prior administration of ketoconazole, an inhibitor of P450, reduced biliary excretion by 50% and effected a corresponding decrease in the amount of drug irreversibly bound to liver proteins. This indicated a role for P450 in the bioactivation of amodiaquine to a reactive metabolite that conjugates with glutathione and protein. 4. De-ethylation and irreversible binding were observed in vitro using male rat liver microsomes, and were again inhibited by ketoconazole. However, no such binding was observed with human (six individuals) hepatic microsomes despite extensive turnover of amodiaquine to desethylamodiaquine. 5. Amodiaquine quinoneimine underwent rapid reduction in the presence of either human or rat liver microsomes. Therefore in vitro studies may underestimate the bioactivation of amodiaquine in vivo. These data indicate that the extent of protein adduct formation in the liver will depend on the relative rates of oxidation of amodiaquine and reduction of its quinoneimine. This in turn may be a predisposing factor in the idiosyncratic hepatotoxicity associated with amodiaquine. 6. Substitution of a fluorine for the phenolic hydroxyl group in amodiaquine blocked bioactivation of the drug in vivo. Insertion of an N-hydroxyethyl function enabled partial clearance of amodiaquine and its deshydroxyfluoro analogue via O-glucuronidation and altered the balance between phase I oxidation and direct phase II conjugation of amodiaquine.

The effect of fluorine substitution on the metabolism and antimalarial activity of amodiaquine

Amodiaquine (AQ) (2) is a 4-aminoquinoline antimalarial which causes adverse side effects such as agranulocytosis and liver damage. The observed drug toxicity is believed to be related to the formation of an electrophilic metabolite, amodiaquine quinone imine (AQQI), which can bind to cellular macro-molecules and initiate hypersensitivity reactions. 5'-Fluoroamodiaquine (5'-FAQ, 3), 5',6'-difluoroamodiaquine (5',6'-DIFAQ,4), 2',6'-difluoroamodiaquine (2',6'-DIFAQ,5), 2',5',6'-trifluoroamodiaquine (2',5',6'-TRIFAQ, 6) and 4'-dehydroxy-4'-fluoroamodiaquine (4'-deOH-4'-FAQ,7) have been synthesized to assess the effect of fluorine substitution on the oxidation potential, metabolism, and in vitro antimalarial activity of amodiaquine. The oxidation potentials were measured by cyclic voltammetry, and it was observed that substitution at the 2',6'- and the 4'-positions (2',6'-DIFAQ and 4'-deOH-4'-FAQ) produced analogues with significantly higher oxidation potentials than the parent drug. Fluorine substitution at the 2',6'-positions and the 4'-position also produced analogues that were more resistant to bioactivation. Thus 2',6'-DIFAQ and 4'-deOH-4'-FAQ produced thioether conjugates corresponding to 2.17% (SD: +/- 0.27%) and 0% of the dose compared with 11.87% (SD: +/- 1.31%) of the dose for amodiaquine. In general the fluorinated analogues had similar in vitro antimalarial activity to amodiaquine against the chloroquine resistant K1 strain of Plasmodium falciparum and the chloroquine sensitive T9-96 strain of P. falciparum with the notable exception of 2',5',6'-TRIFAQ (6). The data presented indicate that fluorine substitution at the 2',6'-positions and replacement of the 4'-hydroxyl of amodiaquine with fluorine produces analogues (5 and 7) that maintain antimalarial efficacy in vitro and are more resistant to oxidation and hence less likely to form toxic quinone imine metabolites in vivo.

Intermittent supervised treatment of tuberculosis at Green Lane Hospital, 1987-8

AIMS

to assess the results of the first two years experience with intermittent supervised treatment of tuberculosis (IST) in Auckland, looking especially at practical problems.

METHOD

the hospital records of the 16 patients who received IST during 1987-8 were reviewed retrospectively, and public health nurses who administered the medications were questioned about problems that were encountered.

RESULTS

two-thirds of those who were given IST were Polynesian. In retrospect, the need for IST could have been anticipated in eight of the 12 patients (67%) who failed to comply with daily treatment. Five of the 16 IST patients presented major problems to the nurses supervising the twice weekly treatment. Poor motivation, itinerancy and alcohol abuse were the most common factors causing difficulty. IST was successfully completed in 13/16 patients (81%) and was abandoned in only one patient. Only two patients completed IST with a drug regimen for resistant organisms. Health nurse supervision resulted in improvements in understanding and attitude to tuberculosis, eventually enabling two patients to self medicate without supervision.

CONCLUSIONS

IST is a practical treatment method in New Zealand, permitting curative therapy in a group of tuberculosis patients who would otherwise create risks of drug resistance, disease reactivation and spreading the disease.

The mechanism of bioactivation and antigen formation of amodiaquine in the rat

A glutathione conjugate of amodiaquine has been isolated and characterized from rat bile after administration of [14C]amodiaquine (50 mumol/kg, 5.0 muCi/rat) to anaesthetized male Wistar rats. Thioether conjugates of amodiaquine in rat bile accounted for a total of 12% of the dose, 5 hr after administration of the drug. In addition, 1% of the dose remained in the liver covalently bound to tissue proteins after 5 hr. These findings provide direct evidence that a chemically reactive metabolite, amodiaquine quinoneimine, has been formed from the drug in vivo. A second major metabolite, desethylamodiaquine, accounting for 14% of the given dose, was present in the liver after 5 hr. Enzyme inhibition studies with ketoconazole-pretreated rats showed that both amodiaquine quinoneimine and desethylamodiaquine formation can be catalysed by cytochrome P450. The demonstration that amodiaquine readily and extensively forms a metabolite in vivo, with strong reactivity towards protein and non-protein thiol groups, may help to explain the idiosyncratic toxicity observed in man.

Pneumocystis carinii pneumonia as a complication of methotrexate treatment of asthma

A 32 year old man with chronic severe asthma, requiring maintenance oral corticosteroids, was started on a weekly dose of methotrexate. Eleven weeks later he developed Pneumocystis carinii pneumonia. In the two years following treatment there has been no recurrence while oral corticosteroid treatment has been continued. Pneumocystis pneumonia should be considered in asthmatic patients taking methotrexate who present with fever, pulmonary infiltrates, and hypoxia.

Effects of water immersion on cardiac output of lean and fat male subjects at rest and during exercise

To investigate the combined effect of water immersion (WI) and lean body mass on cardiac output (Q), 12 healthy young men, 6 lean (fat less than 9%) and 6 fat (fat greater than 18%), were studied at rest and during steady state exercise approximating 30-40% Vo2 max under three experimental conditions. There were on land at 24 degrees C (LND), and immersed in water at 33-34 degrees C to hip level (HIP), and to the xiphoid (XIP). Metabolic measures were determined during 30-s periods from the average breath measurements. Mixed venous PCO2 (PVCO2) was estimated using rebreathing equilibration technique. Cardiac output was calculated by the indirect Fick's principle. In the lean individuals the average Q rose from a resting value of 5.43 +/- 0.43 (LND) to an exercise value of 7.25 +/- 0.40 L/min (XIP), and from resting value of 5.62 +/- 0.40 to an exercise 6.47 +/- 0.5 L/min in the fat individuals. During exercise, the associated increase in Q with increasing WI was significantly (p less than 0.05) higher compared with the land experiments. Inspection of the mean profile corresponding to this increase indicated that an increase in the level of immersion results in a significant (p less than 0.05) increase in the average Q for the lean group. For the fat group, the average Q was significantly (p less than 0.05) larger only at XIP level. At rest, heart rate dropped from 67 +/- 3.36 (LND) to 60 +/- 4.13 (XIP), and from 79 +/- 3.73 to 73 +/- 4.10 BPM for the lean and fat group, respectively. MANOVA analysis showed a significant (p less than 0.05) interaction between WI and group membership, indicating that the effect of WI is significantly different between the two groups. These data indicate that the change in central blood volume with WI depends, in part, on the lean mass of the body.

The interrelationship among bronchial hyperresponsiveness, the diagnosis of asthma, and asthma symptoms

Bronchial hyperresponsiveness (BHR) to inhaled histamine has often been cited as the gold standard in asthma diagnosis, but recently this has been questioned. This report assesses the relationship of BHR to asthma symptoms and asthma diagnosis in a large community-based sample of children. A total of 2,053 children 7 to 10 yr of age were randomly sampled from Auckland primary schools and assessed by a questionnaire and histamine inhalation challenge. In all, 14.3% had had asthma diagnosed, 29.6% reported having had one of the four respiratory symptoms in in the previous 12 months, and 15.9% had BHR (PD20 less than or equal to 7.8 mumol histamine). After a cumulative dose of 3.9 mumol histamine, the percent change in FEV1 from postsaline FEV1 was unimodally distributed, with those in whom asthma had been diagnosed dominating the severe end of the spectrum. However, 53% of those with BHR had no asthma diagnosis, and 41% had no current asthma symptoms. On the other hand, 48% of all subjects with diagnosed asthma and 42% of children with diagnosed asthma and current symptoms did not have BHR. Although severity of BHR tended to increase with wheezing frequency, all grades of severity (including no BHR) were found for any given frequency of wheeze. An existing diagnosis of asthma identified symptomatic children more accurately than did BHR, regardless of the criteria used for BHR or for "symptomatic" and irrespective of ethnic group. In conclusion, BHR is related to, but not identical to, clinical asthma. Bronchial challenge testing is an important tool of respiratory research, but cannot reliably or precisely separate asthmatics from nonasthmatics in the general community.

Anaerobic threshold alterations caused by interval training in 11-year-olds

The purpose of this study was to examine the effects of the interval training on metabolic parameters at maximal work and at the anaerobic threshold in 11 year olds. The subjects were five healthy male children. They trained outdoor for 50 min a day, five times a week for six weeks, using interval work at 25 and 50% above their anaerobic threshold. Before and after training program, they performed a progressive exercise test on a cycle ergometer. During the last 15 sec of each power output measurements were made of oxygen uptake (VO2), carbon dioxide output (VCO2), heart rate (HR), ventilation (VE), ventilatory equivalent for oxygen (VEO2) and ventilatory equivalent for carbon dioxide VECO2). Following training, the group increased their anaerobic threshold (expressed as %VO2max) significantly (P less than 0.05) during the progressive exercise test, by 22%. Also at the anaerobic threshold level, increases were observed following training in CO2 output (VCO2-AT) and respiratory exchange ratio (R). Oxygen uptake (VO2, l.min-1) was increased by 19%, but the difference was not significant (P greater than 0.05). Maximal ventilatory equivalent for (VECO2max) decreased significantly (P less than 0.05). Maximal heart rate was reduced significantly (P less than 0.05). We conclude that training led to an increase of both anaerobic and aerobic metabolism, at any submaximal work above the anaerobic threshold, for this specific age group.

Socioeconomic status in childhood asthma

This study examines the relationship between socioeconomic status (SES) and asthma prevalence and the use of asthma medication. One thousand and fifty European children aged eight and nine years were studied by parent completed questionnaire and histamine inhalation challenge. After controlling for sex of the child and for smokers in the house there were significantly higher lifetime (P = 0.029) and current (P = 0.046) prevalence rates of wheeze in children in low SES groups. There was no relationship between SES and asthma diagnosis, bronchial hyperresponsiveness (BHR: PD20 less than 7.8 mumol), or any combination of BHR with symptoms or diagnosis. The use of bronchodilators and asthma prophylactic drugs was less frequent in the low SES groups of children with wheeze in the last 12 months both with concurrent BHR or irrespective of BHR than in those in high SES groups.

Ethnic differences in prevalence of asthma symptoms and bronchial hyperresponsiveness in New Zealand schoolchildren

Maoris and Pacific Islanders in New Zealand have a higher asthma mortality and hospital admission rates than Europeans. To determine whether difference in asthma prevalence is the major factor underlying these differences in mortality, 2053 Auckland children aged 7-10 years (European 1084, Maori 509, Pacific Islander 460) were randomly sampled from school classes in the Auckland Urban Area, and studied by questionnaire (completed by parents) and histamine inhalation challenge to assess the provocative dose of histamine causing a 20% fall in FEV1 (PD20). Maoris had the highest prevalence rates of respiratory symptoms, and Europeans had rates similar to Pacific Islanders. For "any current wheeze" for example, the prevalence in Maoris was 22.2% compared with 16.1% and 16.3% in the Europeans and Pacific Islanders. The prevalence of diagnosed asthma was similar in the three groups. When bronchial hyperresponsiveness (defined as a PD20 less than or equal to 7.8 mumol histamine) was considered, Europeans had the highest rates (20%), followed by Maoris (13%), and then Pacific Islanders (8.7%). These differences were not accounted for by differences in socioeconomic status, rates of smoking in the home, age, gender, or height. It is concluded that differences in asthma prevalence do not satisfactorily explain the mortality and admission rate differences, although the higher symptom prevalence in the Maoris could be relevant to the higher mortality rate. Maori and Pacific Island children with symptoms of asthma were less likely to be taking prophylactic medication than European children. It is proposed that differences in management are important factors relevant to the increased mortality and morbidity from asthma in Polynesians.

International comparison of the prevalence of asthma symptoms and bronchial hyperresponsiveness

Potential explanations for the higher rates of asthma mortality and hospital admissions in New Zealand (NZ) include greater prevalence of asthma. To evaluate this further, a large community survey has been undertaken. Rates of respiratory symptoms and bronchial hyperresponsiveness (BHR) for children in Auckland, NZ have been compared to those for children in two locations in New South Wales (NSW), Australia: Wagga Wagga (inland) and Belmont (coastal). The methodology used was the same in both studies: parent-completed questionnaire and BHR measured by response to an abbreviated histamine challenge. In Auckland, 1,084 children participated (84% of those selected) and were compared to 769 inland NSW and 718 coastal NSW children. The prevalence of respiratory symptoms, BHR, severity of BHR, and BHR combined with symptoms was similar among Auckland and inland NSW children but lower among coastal NSW children than those from the other two sites. It is concluded that other unidentified factors must be invoked to explain mortality and admission differences between these regions.

Colour vision abnormalities in multiple sclerosis

A battery of colour vision tests was employed to evaluate visual function in patients with multiple sclerosis (M.S.). Colour deficits were found in 45% of patients tested with the Ishihara plates and 42.5% of patients tested with the FM 100-Hue test. 65% of M.S. patients failed at least one of the tests. The colour vision deficits were not restricted to patients with optic neuritis or with visual evoked potential (VEP) abnormalities and there was no significant correlation between an abnormal VEP latency and a colour vision deficit. Colour vision testing may be a useful option to consider in the investigation of M.S. patients, even if there is no other evidence of visual system involvement.

Gastric carcinoid tumours associated with hypergastrinaemia and pernicious anaemia--regression of tumors by antrectomy. A case report

Low gastric acid output leads to hypergastrinaemia, which results in the stimulation of dormant enterochromaffin-like cells in the gastric mucosa; these can progress to carcinoid tumours. A patient is described with this syndrome. Reduction in gastrin levels by antrectomy resulted in regression of the carcinoids.

Control of nosocomial tuberculosis in New Zealand: a window into hospital occupational health?

A survey of six New Zealand hospitals, each of which employs at least one respiratory physician, demonstrated lack of uniformity and several deficiencies in measures to prevent nosocomial tuberculosis. Preemployment screening measures in particular were frequently suboptimal. Suggested improvements include upgrading tuberculosis control policies at a national level, with input from hospital boards, clinicians, and the Department of Health. Future policy changes should be based upon local and national experience and this requires the auditing of hospital control measures. The number of health workers amongst new cases of tuberculosis should also be recorded and taken into account.

Inhaled high-dose beclomethasone in chronic asthma

The effects of high-dose inhaled beclomethasone dipropionate were studied retrospectively in 123 asthma patients who were inadequately controlled on standard doses of beclomethasone dipropionate, or who required oral corticosteroids to control their asthma. High-dose beclomethasone dipropionate was administered by aerosol which delivered 250 micrograms beclomethasone dipropionate per metered dose. Thirty-one percent of the steroid-dependent patients (n = 65) were able to stop maintenance oral steroid after the introduction of beclomethasone dipropionate 250 and a further 48% were able to reduce their daily dosage. The mean reduction in daily maintenance prednisone was 5.2 mg. Comparing a six month period before and during treatment with beclomethasone dipropionate 250, asthma control was improved in 69% of all patients. This was accompanied by a 53% reduction in the number of acute attacks requiring supplementary courses of oral corticosteroid and a 70% reduction in admissions to hospital. Prior to beclomethasone dipropionate 250, 21% of the steroid-dependent patients were maintained on alternate day prednisone whereas after the introduction of beclomethasone dipropionate 250, 44% of those 45 still requiring continuous prednisone were maintained on an alternate-day regimen.

Tuberculosis at Green Lane Hospital 1980-1982

An audit of tuberculosis management at Green Lane Hospital was undertaken by review of the case records of 235 cases of adult tuberculosis. There were 135 men and 100 women (mean age 47 years). Important findings include the large proportion of nonEuropeans (66%) and the frequency of drug resistance. Drug resistance was present in 29% of isolates from nonEuropean immigrants who had resided in New Zealand for a year or less. The adequacy of current medical screening of Pacific Island and South-east Asian visitors and immigrants is discussed in the context of these findings. Treatment regimens used were in accordance with accepted recommendations, although the duration (14 months in uncomplicated disease) was longer than is now thought necessary. Of the 205 patients who completed treatment under our care 186 (91%) were cured, 14 (6.8%) died, 3 (1.5%) relapsed and two defaulted. The median in hospital stay was 32 days and together with the somewhat high relapse rate (1.5%) reflects the absence of facilities for closely supervised outpatient tuberculosis treatment in Auckland.

Combined cholinergic antagonist and beta 2-adrenoceptor agonist bronchodilator therapy by inhalation

The bronchodilator effects of 40 microgram ipratropium bromide (I) and 400 microgram fenoterol (F) by pressurised aerosol and both drugs in combination were compared with placebo (P) in a double-blind study in eight patients with chronic, partially reversible airways obstruction. The four treatments were (1) IP, (2) PF, (3) IF and (4) PP, with the second aerosol administered two hours after the first. Both drugs produced significant bronchodilatation for five hours, the response being greater and more rapid in onset with fenoterol. Both drugs in combination (IF) produced significant additive bronchodilatation from three to six hours after fenoterol. This additive effect may have been due to the improved lung function caused by ipratropium bromide and does not imply a synergistic effect. There were no side-effects reported. The results suggest that both ipratropium bromide and fenoterol are effective bronchodilating agents in patients with chronic asthma.

Giant condyloma (Buschke--Loewenstein tumor) of the anorectum

A case of giant condyloma of Buschke and Loewenstein is presented. The clinical course and pathology of these tumors are reviewed. This case illustrates the delay in establishing the diagnosis in spite of numerous biopsies. It is emphasized that the only effective treatment is wide local excision.

Tracheobronchopathia osteochondroplastica

The clinical, pathological and physiological features of two patients suffering from tracheobronchopathia osteochondroplastica (TO) are described. Unequivocal evidence of extrapulmonary airways obstruction was not able to be obtained by lung function testing, despite extensive central airway involvement in both patients. TO is a rare condition of which there is only one other clinical report from this country. As the bronchoscopic appearance may closely resemble that of endobronchial neoplasms, TO should be remembered in the differential diagnosis of patients with haemoptysis.

Myogenic cells in Kaposi's sarcoma: an ultrastructural study

An ultrastructural study of a metastatic Kaposi's sarcoma in a cervical lymph node demonstrated the presence of endothelial cells, smooth muscle cells, fibroblasts and myofibroblasts. Some of these cells exhibited phagocytic activity in relation to extravasated red blood cells. The ultrastructural features favour the suggestion of an origin of Kaposi's sarcoma from pluripotential mesenchymal cells which may differentiate into more specialised cell types including endothelial, smooth muscle, fibroblastic and myofibroblastic cells.

Recurrent venous thrombosis (thrombophlebitis migrans) and carcinoma of the lung

A case of thrombopheblitis migrans associated with a poorly differentiated adenocarcinoma of the lung is presented. The patient died of a massive pulmonary embolus despite anticoagulant therapy. Disordered fibrinolysis may be the cause of the clotting tendency in this condition.