Michio Arakawa

Proposal of Burkholderia gen. nov. and transfer of seven species of the genus Pseudomonas homology group II to the new genus, with the type species Burkholderia cepacia (Palleroni and Holmes 1981) comb. nov.

Based on the 16S rRNA sequences, DNA‐DNA homology values, cellular lipid and fatty acid composition, and phenotypic characteristics, a new genus Burkholderia is proposed for the RNA homology group II of genus Pseudomonas. Seven species in this group were transfered to the new genus. Thus seven new combinations, Burkholderia cepacia (Palleroni and Holmes 1981), Burkholderia mallei (Zopf 1885), Burkholderia pseudomallei (Whitmore 1913), Burkholderia caryophylli (Burkholder 1942), Burkholderia gladioli (Severini 1913), Burkholderia pickettii (Ralston et al 1973) and Burkholderia solanacearum (Smith 1896) were proposed.

Burkholderia pseudomallei and Melioidosis: Be Aware in Temperate Area

Melioidosis is an infectious disease caused by a Gram-negative rod species of bacterium Burkholderia pseudomallei (former Pseudomonas pseudomallei). It has been regarded as an endemic disease in the tropics especially in the countries of Southeast Asia, because the patients with melioidosis occurred chiefly among the residents in or visitors to these countries and the strains of B. pseudomallei have been detected from natural environments in Southeast Asia. Many review papers on melioidosis have been published since 1953 (2, 3, 5, 17, 33, 36, 46, 57, 66, 103, 115, 128). Previous papers were reported mainly by researchers from developed countries which possessed colonies or had experienced war in these areas. As a matter of fact, physicians in the United States knew almost nothing about melioidosis before a large number of US troops were engaged in the war in Vietnam. It was said that there were 136 patients diagnosed as having melioidosis (nearly 3/4 of them were from the infantry division) in Vietnam during a 13-month

Identification of Oklahoma Isolate as a Strain of Pseudomonas pseudomallei

Based on the morphological, physiological, biochemical, and nutritional characteristics, cellular fatty acid and lipid composition, ubiquinone‐8 as the major respiratory quinone, guanine‐plus‐cytosine content of DNA, DNA‐DNA homology value, and sequence alignment of 16S rRNA nucleotides, Oklahoma isolate was reidentified as a strain of Pseudomonas pseudomallei.

Age-related increase in systolic fraction of pulmonary vein flow velocity-time integral from transesophageal doppler echocardiography in subjects without cardiac disease

The pulmonary vein flow velocity-time profile would be equivalent to the pulmonary vein flow volume-time profile, provided that the cross-sectional area of the pulmonary vein remains unchanged during 1 cardiac cycle. The systolic fraction of the pulmonary vein flow velocity-time integral, a ratio of velocity-time integral of the S wave to the sum of velocity-time integrals of the S and D waves, represents the ratio of left atrial storage volume to left ventricular stroke volume. This systolic fraction may help early filling of the left ventricle through an appropriate storage of blood and generation of driving pressure in the left atrium. Because early filling of the left ventricle is progressively impaired with age, it was hypothesized that this systolic fraction is increased with age. Forty-four noncardiac surgical patients (age range 17 to 70 years) who underwent transesophageal Doppler echocardiography under general anesthesia were studied, and left upper pulmonary vein flow and mitral inflow velocities were recorded. The ratio of peak velocity of the E wave to that of the A wave of mitral inflow velocity-time profile (y) decreased with age (y = -0.0245 x age + 2.41; r = -0.672, p < 0.01). Systolic fraction (y) increased with age (y = 0.00373 x age + 0.514; r = 0.656, p < 0.01). The age-related increase in the systolic fraction of pulmonary vein flow velocity-time integral may account for the compensation for impaired early filling of the left ventricle in elderly patients.

Diastolic compliance of the left atrium in man: A determinant of preload of the left ventricle

SummaryDuring the ventricular slow-filling period, both the left atrium and left ventricle fill passively, and their respective internal pressures equalize, becoming evenly elevated. If the diastolic chamber compliance of the left atrium is smaller than that of the left ventricle, we expect the inflowing blood to be distributed more to the left ventricle than to the left atrium during this period. We examined the magnitude of the diastolic compliance of the left atrium and the left ventricle at the end of the slow-filling period.We studied 10 patients, mostly with a mild degree of coronary artery disease, in whom hemodynamic variables were almost within normal limits. To estimate the compliance of the left atrium, we recorded the left atrial pressure directly (by the Brockenbrough technique) and determined the left atrial volume by biplane cineatriography. We determined the diastolic compliance of the left atrium from the pressure-volume relations between the nadir of the x trough and the peak of the v wave by fitting them to an exponential equation, P=b · eaV (P = pressure, V = volume, a, b = constants). The diastolic compliance of the left ventricle was determined from the pressure-volume relations during the ventricular slow-filling period.The compliances of the left atrium and the left ventricle at the pressure at the end of the ventricular slow-filling period were 1.60±0.41 (mean ± SD) ml · mmHg−1 · m−2 and 4.22±1.12, respectively. The ratio of compliance of the left ventricle to that of the left atrium was 2.60±0.71.Since the diastolic compliance of the left ventricle is 2–3 times larger than that of the left atrium, we suggest that during the slow-filling period, the interaction between the left atrial and left ventricular diastolic compliances provides preferential delivery of blood to the left ventricle and acts as a determinant of volume at the end of the slow-filling period of the left ventricle.

Intermittent Oversensing due to Internal Insulation Damage of Temperature Sensing Rate Responsive Pacemaker Lead in Subclavian Venipuncture Method

A 49‐year‐old male patient developed sensing failure (oversensing) 6 months after the implantation of a temperature sensing rate responsive pacemaker by the subclavian venipuncture method. Intermittent oversensing appeared in the sitting position, but did not appear in the supine position. Temperature telemetry showed an excessive fluctuation of the temperature data points while sitting and while doing a treadmill exercise test. Internal insulation damage was found approximately 33 cm from the distal tip of the expianted lead. The electrical resistance between one thermistor coil and the pacing coil changed from 9 kiloohms to 40 ohms when moderate pressure was applied to the outside lead in the fault area. This electrical shunt resulted from internal insulation damage that resulted from compression of the pacemaker lead between the first rib and the clavicle.

Origin of the Water-Clear Cell in the Parathyroid Gland of the Golden Hamster

Water-clear cells and transitional forms between the chief cells and water-clear cells were observed in the parathyroid gland of the golden hamster. Their ultrastructure is described, and the origin of the water-clear cell is discussed.

Transesophageal Doppler echocardiographic assessment of pulmonary venous flow pattern in subjects without cardiovascular disease

This study was designed to assess pulmonary venous flow dynamics using transesophageal Doppler echocardiography. Under general anesthesia, we studied 54 surgical patients with no history or physical evidence of cardiac disorders. In all patients pulmonary venous flow was easily identified by transesophageal color flow mapping. Pulmonary venous flow pattern, which was obtained clearly in 85% (4654) of patients by transesophageal pulsed Doppler echocardiography, was tri- or quadriphasic. The first wave, which was often biphasic in elderly patients, occurred during ventricular systole (S wave). The second wave occurred in diastole during the early ventricular filling phase of mitral flow (D wave). The third wave was reverse flow toward the pulmonary vein during atrial contraction (A wave). The following variables were measured: the peak flow velocities of each wave (PFVs, PFVd, PFVa), and the ratio of PFVs to PFVd (PFV(S/D)). The PFVd correlated with age (r=−0.56, P<0.001), indicating age-related decrease. The PFV(S/D) correlated with age (r=0.61, p<0.001), indicating age-related increase. These results would indicate that the contribution of pulmonary venous flow during diastole to total pulmonary venous flow decreases with age.Our data suggest that age-related diastolic dysfunction of the left ventricle would affect pulmonary venous flow dynamics and that left atrial storage volume during ventricular systole would increase with age.

Ultrastructural studies on the effects of hypergravity environment on the parathyroid glands in golden hamsters of different ages

The ultrastructure of the parathyroid glands of infantile, young, adult and senile golden hamsters subjected to a hypergravity environment was studied. In the parathyroid glands of 5-, 10- and 20-day-old, and 1- and 3-month-old golden hamsters exposed to a hypergravity environment, the Golgi complexes were significantly increased, and in 5-, 10- and 20-day-old, and 1- and 8-month-old animals exposed to a hypergravity environment, the cisternae of the granular endoplasmic reticulum appeared to be increased as compared to those of each control group. In addition, in centrifuged animals numerous prosecretory granules were observed in the Golgi areas, and many secretory granules were located in the peripheral cytoplasm. The ultrastructure of the parathyroid glands of 14-month-old centrifuged animals resembled that of 14-month-old control animals. These results suggest that the secretory activity of the parathyroid gland may be stimulated in infantile, young and adult golden hamsters subjected to a hypergravity environment and may not be stimulated in senile animals subjected to a hypergravity environment.

Correction for apparent prolongation of mean transit time resulting from response time in a thermodilution system

A method of correcting an apparent prolongation in the measured transit time (MTT) resulting from the response time of the thermodilution system was investigated. The mean response times (MRTs) were measured for five commercially available thermistor-tipped catheters by recording their step function response curves. Using a flow loop model filled with saline through a mixing chamber, pairs of thermodilution curves were recorded simultaneously with pairs of catheters, and the influence of MRT on MTT was studied for the constant flow rates of 1-6 L/min. The difference in MRTs between a pair of thermodilution systems correlated with the difference in MTTs between a corresponding pair of thermodilution curves, yielding an equation. It was concluded that the apparent prolongation of MTT due to response time can be eliminated by subtracting the MRT from the measured MTT.<<ETX>>