Phylogenetic Analysis of Alloiococcus otitis gen. nov., sp. nov., an Organism from Human Middle Ear Fluid

The partial 16S rRNA sequence of an unknown bacterium that was originally isolated from middle ear fluids of children with persistent otitis media was determined by reverse transcription. A comparison of this sequence with sequences from other gram-positive species having low guanine-plus-cytosine contents revealed that this bacterium represents a new line of descent, for which the name Alloiococcus otitis gen. nov., sp. nov., is proposed. The type strain is strain NCFB 2890.

Specific and intraspecific molecular typing of lactococci based on polymorphism of DNA encoding rRNA

The rRNA gene restriction patterns or species of the genus Lactococcus were determined. Chromosomal DNA was digested with endonucleases and probed with radiolabelled DNA complementary to rRNA synthesized by random oligonucleotide priming using reverse transcriptase. Highly discriminatory restriction patterns were obtained which served to distinguish the five currently recognized lactococcal species. In addition the observed variations in the patterns at intra-specific level indicate that rRNA gene restriction fingerprinting may be of value in distinguishing the individual strains for epidemiological studies, and monitoring and checking authenticity of starter strains.

Importance of venodilatation in prevention of left ventricular dilatation after chronic large myocardial infarction in rats: a comparison of captopril and hydralazine

In rats with large myocardial infarctions, we compared the effects of captopril, a presumed arterial and venous vasodilator, with hydralazine, which is thought primarily to be an arterial vasodilator. To determine if the effects of captopril were dependent on the pathophysiological consequences of heart failure, we also studied a group of noninfarcted rats treated with captopril. In noninfarcted rats treated with captopril, left ventricular (LV) systolic and mean aortic pressures decreased from 132 +/- 12 to 107 +/- 15 mm Hg and 122 +/- 1 to 100 +/- 2, respectively (p less than 0.01). In noninfarcted rats, captopril decreased LV weight, LV weight/body weight, and total heart weight/body weight but produced no effects on the peripheral venous circulation. Rats subjected to coronary artery ligation were selected by ECG criteria to have large myocardial infarctions and were treated for 4 weeks with captopril (n = 8), hydralazine (n = 5), or placebo (n = 9). In infarcted rats treated with captopril, LV systolic, mean aortic pressures and LV end-diastolic pressure (LVEDP) decreased (p less than 0.01) from 115 +/- 4 to 86 +/- 3 mm Hg, 106 +/- 4 to 74 +/- 3 mm Hg, and 23 +/- 2 to 11 +/- 2 mm Hg, respectively. Mean circulatory filling pressure decreased (p less than 0.05) from 11.2 +/- 0.6 to 8.7 +/- 0.8 mm Hg and venous compliance increased (p less than 0.05) from 2.04 +/- 0.07 to 2.70 +/- 0.20 ml/mm Hg/kg. Blood volume decreased (p less than 0.05) from 67.3 +/- 0.9 to 58.2 +/- 1.8 ml/kg.(ABSTRACT TRUNCATED AT 250 WORDS)

A comparison of multiple and single sleep latency and cerebral evoked potential (P300) measures in the assessment of excessive daytime sleepiness in narcolepsy-cataplexy

A direct comparison was made between the amplitude of evoked potential (EP) component P3 (by the P300 paradigm), a known sensitive EP correlate of sleepiness, and sleep latency measures (both to stage 1 or rapid eye movement [REM] and to stage 2 or REM) of the Multiple Sleep Latency Test (MSLT) in 11 untreated narcoleptics and matched controls. Repeated P3 measures were performed immediately prior to standard MSLT naps at 10:00 a.m., 12:00 noon, 2:00 p.m., 4:00 p.m., and 6:00 p.m. Using discriminant analysis and F tests, all three measures (P3 and both by MSLT) were found to distinguish the two groups for collapsed five-nap data, and all showed essentially parallel circadian time-of-day effects, with greatest sleepiness in the midafternoon. The MSLT, however, was somewhat more powerful for collapsed data. Both tests misclassified some subjects as belonging to the other group, with greater misclassification for both tests in the control group and more overall for the P3 measure. Adding the two sleep onset REM period (SOREMP) criteria on MSLT for narcolepsy, one patient was still classified as normal. Analysis of data from individual naps indicated that the MSLT was considerably more powerful in discriminating groups than was P3 amplitude, and it did so for all five naps.

Effects of 10- to 12-day treatment with L-thyroxine in rats with myocardial infarction

The effects of treatment with L-thyroxine (T4) for 10-12 days on left ventricular (LV) function and myosin isoenzyme content in rats with LV dysfunction after myocardial infarction were studied. Electrocardiogram (ECG) criteria were used to select animals with large myocardial infarctions. These animals were divided into six groups: control and five treatment groups that received daily subcutaneous injections of T4 (1.5, 3, 6, 10, or 15 micrograms/100 g body wt) for 10-12 days. Intravascular pressures were then measured with micromanometer-tipped catheters, and the hearts were analyzed for myosin isoenzyme distribution. The lowest dose of T4 (1.5 micrograms) produced no changes in heart rate, LV pressure or aortic pressure (AoP), myosin isoenzyme composition, or serum T4 levels. Larger doses of T4 (3, 6, 10, and 15 micrograms) produced increases in LV rate of pressure development (dP/dt), heart rate, and T4 levels but did not change LV pressure or AoP. Myosin isoenzyme composition in the control group showed increases in the proportion of the V3 form and decreases in the V1 form compared with the normal pattern. T4 administration produced dose-dependent increases in the V1 myosin isoform and corresponding decreases in the amount of the V2 and V3 forms. Heart rate increases observed with larger doses of T4 could be prevented by addition of propranolol (500 mg/l) to the drinking water. However, in rats treated with T4 and propranolol, LV pressure, AoP, LV dP/dt, and myosin isoenzyme composition were unchanged compared with T4-treated rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Serial changes in left ventricular relaxation and chamber stiffness after large myocardial infarction in rats

To determine the time course of changes in left ventricular diastolic properties after a large myocardial infarction, we serially measured left ventricular relaxation, chamber stiffness, and the ratio of left ventricular cavity to wall volume (V/VW) after coronary artery ligation in rats. Left ventricular relaxation was measured during the occlusion and then both relaxation and chamber stiffness were measured at 3 hr, 24 hr, and 3, 5, and more than 22 days after infarction. Left ventricular pressures and left ventricular dP/dt were recorded with micromanometer-tipped catheters. Left ventricular relaxation was measured by computer digitization of the left ventricular pressure tracings and averaged over 100 to 150 cardiac cycles. Five chamber stiffness constants were calculated from pressure-volume curves that were obtained ex vivo. We found ventricular relaxation prolonged for the first hour after coronary occlusion; relaxation was maximally prolonged at 10 to 15 min after onset of occlusion. After 1 hr relaxation returned to normal. However, by 5 days ventricular relaxation was again prolonged. Left ventricular stiffness constants were increased at 3 and 24 hr, resulting in a shift of the left ventricular pressure-volume relation to the left. At 3 days after coronary artery ligation, all stiffness constants and the pressure-volume relation returned to normal. At more than 22 days the pressure-volume relation was shifted to the right and the stiffness constant for low filling pressures was decreased. V/VW was significantly decreased from 0.603 +/- 0.021 at 3 and 24 hr to 0.379 +/- 0.024 and 0.362 +/- 0.032, respectively. V/VW was significantly increased at more than 22 days (0.921 +/- 0.094).(ABSTRACT TRUNCATED AT 250 WORDS)

Variability of the thymidine labeling index in squamous cell carcinoma of the head and neck

Tritiated thymidine (3HTdR) labeling is the standard technique for determining the kinetic activity of tumors. This method has been used to label multiple sections of tumor specimens obtained from seven patients with advanced squamous cell carcinoma of the head and neck. Considerable variability was observed in the labeling index in different sites from the same specimen. To reduce the large sampling error due to heterogeneity, we recommend that an average value be determined from multiple sections when employing this technique.

Complex event-related potentials (P300 and CNV) and MSLT in the assessment of excessive daytime sleepiness in narcolepsy-cataplexy

The P300 and contingent negative variation (CNV) evoked potential (EP) paradigms were performed by 12 untreated narcoleptics and controls immediately prior to each nap of the Multiple Sleep Latency Test (MSLT) in order to assess whether they might hold promise as rapid quantitative techniques to assess excessive daytime sleepiness. The Stanford Sleepiness Scale (SSS) was also completed across test days and immediately before and after both the evoked potential recordings and MSLT naps. MSLT findings confirmed shorter sleep latencies and frequent SOREMPs in narcoleptics and a strong mid-afternoon increase in sleepiness based upon pressure for NREM sleep in both groups. On SSS narcoleptics were sleepier and they showed greater increase in sleepiness induced by the EP tests and greater sleepiness reduction by the MSLT naps. In the P300 paradigm, narcoleptics showed smaller component P3 amplitudes and larger P1 amplitudes. In the CNV paradigm, N1 latencies were greater in narcoleptics to both S1 and S2 and the post-CNV negative component was larger: but no significant differences were seen for the main CNV measures of negativity amplitude in the first or second halves of the response. The P300 paradigm but not the CNV, therefore, appeared to be a sensitive EP measure of sleepiness. Finally, EP components in both the P300 and CNV paradigms showed time-of-day (circadian) differences between narcoleptics and controls.

Differences between REM and NREM sleepiness measured by event-related potentials (P300, CNV), MSLT and subjective estimate in narcolepsy-cataplexy

Differences between 'REM sleepiness' and 'NREM sleepiness' states in wakefulness studied respectively prior to REM-containing and NREM-only multiple sleep latency test (MSLT) naps were compared by complex evoked potentials (P300, CNV), subjective estimate (Stanford Sleepiness Scale, SSS) and MSLT measures in 12 untreated patients with narcolepsy-cataplexy. The EP paradigms lasted about 7 min each and were done during the 10 min immediately before MSLT naps at 10.00, 12.00, 14.00, 16.00 and 18.00 h. SSS forms were completed immediately before and after the EP studies and MSLT naps. Patients were studied on 2 days and performed either the P300 or CNV paradigm on each day. 'REM sleepiness' was found to be subjectively and objectively (shorter mean sleep latency on MSLT) greater. Although subjects were sleepier in REM sleepiness, the subsequent REM nap was relatively more refreshing and reduced SSS estimates to levels equivalent to those after NREM-only naps. EP measures also showed differences between the 2 sleepiness states. REM sleepiness was associated with a significantly larger P2 component (in both the P300 paradigm and the CNV paradigm), a strong but not significant trend towards reduced amplitude of the P3 component, and almost total suppression of the slow negative components of the CNV. REM sleepiness and NREM sleepiness therefore appear to be district and differentiable cerebral states.

Excessive daytime sleepiness and the pathophysiology of narcolepsy-cataplexy: a laboratory perspective

The main disabling symptom of narcolepsy-cataplexy is shown to be the unrelenting excessive daytime sleepiness (EDS) based upon controlled studies of socioeconomic effects and the poor response to treatment. Objective performance deficits mainly involve tests of ability to sustain performance on repetitive boring tasks and are reversible by improved alertness. Physiologically, EDS is seen to represent relatively slow waxing and waning of alertness rather than punctate microsleeps. Evidence is provided for complex cerebral evoked potentials (P300, contingent negative variation) being very sensitive EDS measures comparable to the multiple sleep latency test (MSLT). EDS appears to have qualitatively somewhat different forms mainly reflecting pressure for REM sleep (REM sleepiness) or pressure for NREM sleep (NREM sleepiness), which have different effects on cerebral evoked potentials as well as subjective and objective (MSLT) differences. It is argued that in pathophysiological terms narcolepsy may best be considered a disease of state boundary control.

Acromegaly and bronchial carcinoid. Effect of removal of the latter

A patient with a long-standing history of bronchial carcinoid and acromegaly was studied. There was pituitary enlargement with an intrasellar mass (brain computed tomography scan), high basal GH levels, and abnormal GH and other pituitary hormones response to oral glucose and a combined test (LHRH, TRH, insulin). After resection of the bronchial carcinoid, basal GH was normal, GH was normally suppressed during OGTT, pituitary function was within expected normal range, and there was regression of the pituitary tumor together with clinical improvement. These data suggest that the patient's acromegaly was secondary to pituitary stimulation due to the bronchial carcinoid.

Does memory impairment exist in narcolepsy-cataplexy?

Approximately one-half of patients with the narcolepsy-cataplexy syndrome suffer from subjective memory problems, mainly involving recent events. Ten untreated narcoleptic patients (7 male, 3 female, aged 28-65 years) with such problems and 10 matched controls were given a battery of tests to study the complaint. Tests included the digit span, Knox cube, recurring figures (verbal and nonverbal), visual reproduction, paired associates learning and logical memory test, plus naming and fluency tests to control for language capabilities. No significant intergroup differences were found. It is concluded that narcoleptics do not have a true organic memory deficit, but rather experience a subjective problem due to drowsiness which they are able to suppress during short testing sessions in a laboratory environment.