Bilateral absence of the superior vena cava.

Congenital anomalies of the superior vena cava are rare and often coexist with other cardiac abnormalities. In this report, we present a case of absent bilateral superior vena cava with no associated cardiac anomaly. Blood from the arms, head, and upper torso returned to the right atrium through the azygos vein and the inferior vena cava, mimicking chronic superior vena cava obstruction.

Peripheral frequency mis-match in the primitive ensiferan Cyphoderris monstrosa (Orthoptera: Haglidae).

Peripheral auditory frequency tuning in the ensiferan insect Cyphoderris monstrosa (Orthoptera: Haglidae) was examined by comparing tympanal vibrations and primary auditory receptor responses. In this species there is a mis-match between the frequency of maximal auditory sensitivity and the frequency content of the species' acoustic signals. The mis-match is not a function of the mechanical properties of the tympanum, but is evident at the level of primary receptors. There are two classes of primary receptors: low-tuned and broadly tuned. Differences in the absolute sensitivity of the two receptor types at the male song frequency would allow the auditory system to discriminate intraspecific signals from sounds containing lower frequencies. Comparisons of tympanal and receptor tuning indicated that the sensitivity of the broadly tuned receptors did not differ from that of the tympanum, while low-tuned receptors had significantly narrower frequency tuning. The results suggest that the limited specialization for the encoding of intraspecific signals in the auditory system of C. monstrosa is a primitive rather than a degenerate condition. The limited specialization of C. monstrosa may reflect the evolutionary origin of communication-related hearing from a generalized precursor through the addition of peripheral adaptations (tympana, additional receptors) to enhance frequency sensitivity and discrimination.

Mycobacterium sp. as a possible cause of hypersensitivity pneumonitis in machine workers.

Hypersensitivity pneumonitis (HP) in workers exposed to metal removal fluids (MRFs) is increasing. This study supports the hypothesis that aerosolized mycobacteria colonizing the MRFs likely cause the disease. Three case studies of HP outbreaks among metal workers showed potentially high exposures to a rare and newly proposed Mycobacterium species. Retrospective review of samples submitted to our laboratory showed an association between presence of mycobacteria and HP.

Pharmacokinetics of flosequinan in patients with heart failure.

OBJECTIVE: The pharmacokinetics of flosequinan were studied in a group of 18 patients with chronic cardiac failure. RESULTS: After a single dose of 100 mg, Cmax of the parent compound (2.52 mg.l-1) was recorded at 1.4 h, and of the sulphone metabolite flosequinoxan at 21.7 h. The plasma elimination half lives of the parent compound (6.4 h) and of the metabolite (54.3 h) were prolonged compared to previous studies in normal volunteers. After repeated dose administration for 36 days, the kinetics of the parent compound and metabolite remained essentially unchanged with an expected significant accumulation of metabolite (Cmax 8.4 vs 3.21 mg.l-1). No adverse effects were observed. CONCLUSION: It is possible that altered drug kinetics in patients with heart failure, probably related to altered hepatic blood flow, could contribute to drug toxicity.

Long-term evaluation of treatment for chronic heart failure: a 1 year comparative trial of flosequinan and captopril.

Two hundred and nine patients with moderate to severe chronic heart failure, all of whom remained symptomatic despite at least 80 mg of frusemide daily, were randomized to 12 months treatment with flosequinan or captopril. The patients were stratified into two groups, a treadmill group and a corridor walk test group, depending upon their exercise capability. Sixty-five out of 102 patients randomized to flosequinan and 43 out of 107 randomized to captopril (p < 0.001) did not complete the study. There was no difference between the groups in mortality: 19 patients died while taking flosequinan and 15 while taking captopril. Both drugs had similar effects on treadmill exercise tolerance; the mean increase at week 52 was 117 seconds in the flosequinan group and 156 seconds (p = 0.57) for the captopril group. For those patients stratified to the corridor walk test only, there was also very little difference in the improvement at 52 weeks; the mean increase for patients randomized to flosequinan was 61 meters and captopril was 75 meters (p = 0.65). However, when the walk tests from all patients are examined, captopril produced a significant improvement compared with flosequinan at week 52 (p = 0.015). Flosequinan has similar long-term efficacy to captopril but is associated with a higher incidence of adverse events.

Streptokinase neutralisation titres up to 866 days after intravenous streptokinase for acute myocardial infarction.

OBJECTIVE: To follow the change in streptokinase neutralisation titres in a group of patients after treatment with streptokinase for acute myocardial infarction. DESIGN: Venous blood samples suitable for analysis were obtained up to 866 days after treatment with 1.5 million units of streptokinase in 189 patients. The ability of the patient's plasma to inhibit lysis of a thrombin clot by streptokinase was assessed. SETTING: A coronary care unit in a district general hospital. PATIENTS: A retrospective review of coronary care records and the district health authority computer showed that 329 patients who had received streptokinase were alive. All were invited for venepuncture and 220 (67%) attended. Satisfactory samples were obtained from 189 patients. RESULTS: Raised titres of antibody sufficient to neutralise a standard dose of 1.5 million units of streptokinase were found in 90% of patients. There was a fall in streptokinase neutralisation titre with increasing time after administration of streptokinase (r = -0.35, P < 0.0001) and though there was considerable variation among the group the neutralisation titre was higher than in the general population in all patients, even those who had received streptokinase at least two years previously. CONCLUSION: The ability of streptokinase to lyse a thrombin clot was appreciably inhibited in vitro by the plasma from patients who had received 1.5 million units of streptokinase. High streptokinase neutralisation titres persisted for a long time after the use of streptokinase as thrombolytic treatment for acute myocardial infarction. Readministration of streptokinase may not be efficacious for considerably longer than the one year currently advocated. Until the in vivo effects of streptokinase readministration are known a non-antigenic thrombolytic agent should be used instead.

Tumour necrosis factor alpha in severe congestive cardiac failure.

OBJECTIVE: To examine the concentration of circulating tumour necrosis factor alpha (TNF alpha) in patients with severe congestive heart failure (New York Heart Association class IV) during one year and to correlate changes in this cytokine with changes in plasma noradrenaline, plasma renin activity, and weight. DESIGN: A prospective study of the role of TNF alpha in severe chronic heart failure. Blood samples were collected at intervals of three months. SETTING: Medical research centre of a teaching hospital. PATIENTS: 16 patients with chronic stable severe heart failure. INTERVENTIONS: Vasodilator treatment with captopril or flosequinan. MAIN OUTCOME MEASURES: Changes in TNF alpha and the correlation with changes in plasma noradrenaline, plasma renin activity, and weight during optimal medical treatment for one year. RESULTS: The mean concentration of TNF alpha was greater than the upper 95% confidence interval for healthy controls throughout the year of the study but there was considerable between and within patient variation. No correlation was seen between TNF alpha and plasma noradrenaline, plasma renin activity, or weight. CONCLUSIONS: The stimulus resulting in enhanced plasma concentrations of TNF alpha in congestive heart failure remains unclear and concentrations at any particular time were not prognostic.

How the Blues are using health care data.

Insurers are investing in information technology to provide the data that are essential to the management of their delivery systems. A Blue Cross and Blue Shield medical director explains some practical applications, including outcomes evaluation, provider selection and practice pattern comparisons.

Intracardiac thrombus formation in association with hydatid disease.

Cardiac hydatid disease is rare, but life threatening. A pedunculated hydatid cyst which mimicked a left atrial myxoma was diagnosed on two-dimensional echocardiography. The degree of cardiac involvement at necropsy was much greater than indicated by either echocardiography or limited cardiac catheterization. The suggestion that only echocardiography be performed before surgery is undertaken may be inappropriate in many cases.

Antistreptokinase titres after intravenous streptokinase.

Streptokinase neutralisation titres were measured in a series of 25 patients who received streptokinase for the treatment of acute myocardial infarction. Before treatment, neutralisation titres were low (0.3 X 10(6) neutralisation units or less) in all patients. 3 months after treatment, neutralisation titres in 24 were such that a typical therapeutic dose of 1.5 million units of streptokinase would have been fully neutralised. At 4 1/2-8 1/2 months, 18 of 20 patients had neutralisation titres such that at least 50% of a dose of 1.5 million units of streptokinase would have been neutralised. After 8 months, neutralisation titres ranged from 0.4 to 2.0 million units in 8 patients. A decision to readminister streptokinase within 8 months (and probably up to 1 year) of previous thrombolytic treatment should take account of the neutralising capacity of plasma and the dose should be adjusted accordingly.

Bat predation and its influence on calling behavior in neotropical katydids.

Insectivorous bats have influenced the development of antipredator behavior in moths, green lacewings, crickets, and mantids; until recently, such adaptations were unknown in katydids. Foliage-gleaning bats in Panama can use the female-attracting, airborne calling songs of nocturnal katydids to locate prey. They also feed heavily on these insects. Katydid species sympatric with these bats exhibit markedly reduced calling song duty cycles. Males supplement shortened songs with complex, species-specific tremulations that generate vibrations that are inaudible to bats but reach conspecific females through a shared plant substrate. Female katydids do not call audibly but are also preyed on in large numbers, perhaps as a result of moving toward calling males.

Physicians' attitudes to four common problems: hypertension, atrial fibrillation, transient ischaemic attacks, and angina pectoris.

A questionnaire was completed by 341 senior physicians on their attitudes to four common cardiovascular problems. Their replies showed that uncertainty about the end point for diastolic blood pressure still prevails and that their approach to the management of hypertension of differing severity in men and women of varying ages stems more from personal belief than from the results of clinical trials. Unless patients with atrial fibrillation also had mitral valve disease anticoagulation was not thought to be necessary, thereby making it ethically possible to carry out a trial of anticoagulants in stroke prevention on patients with atrial fibrillation but no valvular disease. The physicians' suggestions for very active management in transient ischaemic attacks extended beyond the evidence available to them, whereas their approach to the use of coronary arteriography closely reflected the results of clinical trials. These findings may indicate that recent cardiovascular trials that have provided definitive results have had more impact than earlier inadequate studies.

Utilization of exogenous siderophores by Campylobacter species.

The availability of iron to potentially pathogenic bacterial strains is restricted by the iron-binding proteins of the host. In this study, we examined 40 strains of Campylobacter species grown under iron-limiting conditions. While the strains produced no detectable siderophores, all the isolates freely utilized exogenous siderophores produced by other organisms as iron carriers. These data suggest that the use of an exogenous siderophore (either purified or present in a coinfecting microorganism) may be important in developing a suitable laboratory model for campylobacteriosis.

Comparison of four hippurate hydrolysis methods for identification of thermophilic Campylobacter spp.

The test for hippurate hydrolysis is critical for separation of Campylobacter jejuni and C. coli strains. Glycine and benzoic acid are formed when hippurate is hydrolyzed by C. jejuni. The test used in most laboratories is one of several variations of the ninhydrin tube test described by Hwang and Ederer (M. Hwang and G. M. Ederer, J. Clin. Microbiol. 1:114-115, 1975) for detection of glycine. We evaluated three modifications of the Hwang and Ederer method and the gas-liquid chromatographic (GLC) method described by Kodaka et al. (H. Kodaka, G. L. Lombard, and V. R. Dowell, Jr., J. Clin. Microbiol. 16:962-964, 1982) for detecting benzoic acid. Campylobacter strains comprised 22 C. jejuni, 11 C. coli, and 8 C. laridis strains. The species identification of each strain was confirmed by DNA relatedness. All strains of C. jejuni were positive and all strains of C. coli and C. laridis were negative by the GLC method for detecting hippurate hydrolysis, whereas three strains of C. jejuni gave negative or variable results in the tube tests. The GLC method is more sensitive than the tube methods for detecting hippurate hydrolysis and should be used on cultures yielding variable or questionable test results.

Epidemiologic and laboratory investigation of an outbreak of Campylobacter enteritis associated with raw milk.

An outbreak of gastroenteritis occurred in March-April 1981, in Wichita, Kansas, and involved more than 250 persons who drank raw milk from a single local dairy. Campylobacter jejuni was recovered from 60 of 116 (52%) persons in households that had one or more ill family members. A cohort study of families that belonged to a food cooperative that purchased raw milk from the implicated dairy showed a significant association between illness and having drunk raw milk. Thirty-nine of 55 (71%) persons who drank raw milk became ill compared with four of 36 (11%) persons who did not drink raw milk (p less than 0.01, t test, accounting for clustering). Peak (convalescent) antibody titers to C. jejuni, determined by indirect immunofluorescence, in 20 raw-milk drinkers showed a geometric mean of 1:27 in contrast to geometric mean titer of 1:6 in 10 well persons from the cohort who did not drink raw milk (p less than 0.002, t test). C. jejuni was recovered from 21 of 34 (66%) raw-milk drinkers, versus none of 26 people who did not drink raw milk (p less than 0.001, Fisher's exact test, one tailed). C. jejuni of the same serotype was isolated from the case-patients and from rectal swabs of cows in the dairy. These findings indicate that raw milk contaminated by Campylobacter was the vehicle for this outbreak.

Comparison of the Penner and Lior methods for serotyping Campylobacter spp.

We compared two Campylobacter serotyping systems by using 1,405 isolates of Campylobacter collected from human, animal, and environmental sources during epidemiologic investigations and special studies. We found 96.1% of isolates to be typable by the Penner method for heat-stable antigens, which involved the use of an indirect hemagglutination technique, and 92.1% of isolates to be typable by the Lior method for heat-labile antigens, which involved the use of a slide agglutination technique and absorbed antisera. Absorbed antisera were not required for the Penner method, making that method less difficult to implement. The Lior method was simpler to perform and gave more rapid results than did the Penner method. Cultures frequently reacted in multiple antisera with the Penner method, whereas multiple reactions were rare with the Lior method. Thus, results were easier to interpret with the Lior system. Strains of a single serotype in one system were sometimes found to be multiple serotypes in the other system; hence, the two methods have the potential to be complementary. Both systems were comparable in serotyping isolates from human and nonhuman sources and for evaluating the relationship of strains collected during outbreak investigations.