Evaluation of arterial obstructive leg and foot disease by three-phase bone scintigraphy.

BACKGROUND: The level selected for amputation should generally be the lowest compatible with tissue viability, with a reasonable expectation of wound healing in patients with arterial obstructive leg and foot disease, but determining the amputation level of an ischemic lower limb remains controversial. The general consensus is that a decisive and final decision about the amputation level should be made intraoperatively based on the extent of hemorrhage from the incised skin and soft tissue, and the degree of viability of the stump. OBJECTIVE: To estimate the extent of such hemorrhage, and thus suggest the level of amputation preoperatively, the author applied three-phase bone scintigraphy (TPBS) to assess the blood flow in the small arteries and capillary vessels. METHOD: TPBS was performed in patients scheduled to undergo lower limb amputation in an attempt to determine the appropriate amputation level preoperatively, objectively, and visually. Imaging results of this examination were compared with the clinical findings in three cases of arterial obstructive foot disease. RESULTS: The "capillary phase" depicted the perfusion of blood from the small arteries to the capillary vessels. Decreased accumulation in the capillary phase appeared as two distinctive states: one of clinically remarkable necrosis and the other of decreased blood flow in the small arteries and capillary vessels. The latter inevitably causes necrosis and infection postoperatively. CONCLUSION: The results of this study suggest that TPBS is an extremely useful tool in the evaluation of physiological dysfunction and the likely amputation level in patients with arterial obstructive leg and foot disease.

Resolution of a position-sensitive proportional-counter with a resistive anode wire of carbon fiber

Theoretical and experimental analyses have been performed to examine the position resolution of a proportional counter with a 7-microm diameter carbon fiber as a resistive anode, which is used to encode one-dimensional positions of incident photons according to the charge-division method. These analyses have clearly shown that the carbon fiber is applicable to the position sensing of the order of 100-200 microm as long as the filled gas is pressurized at near 10 atm.

Ultrasonographic analysis of shoulder rotator cuff tears.

Seventy-nine shoulders suspected of rotator cuff tears were examined by ultrasonography (US) and forty-three received surgery. Long and short axis scans were performed and findings of each were separately classified according to a five-grade system, and the results were correlated with the actual extent of tear observed during surgery. Internal echogenicity and subacromial impingement were analyzed before and after surgery. A accuracy of US in detecting rotator cuff tears was analyzed. In addition, the correlation between cuff shape observed by US before surgery and actual shape observed during surgery was assessed. It was noted that cuff thinning and abnormalities in shape did not recover to normal after surgery. However, in the cases of discontinuities observed by US before surgery, US findings indicated that the torn cuff was anchored to the greater tuberosity and functional during active motion. Although post-operative US findings were not normal, clinical results were good in most cases. Sensitivity of US for detecting rotator cuff tear was 100% and specificity 94%. US is non-invasive, cost effective and allows the physician to examine the joint while it is in motion. Therefore, at this time, we use US as a screening method for detecting rotator cuff tears. Furthermore, US allows us to check for re-tears while the joint is in motion, which is essential for accurate diagnosis.

Simultaneous fracture-dislocations of the distal and proximal interphalangeal joints.

Sixteen cases of simultaneous fracture-dislocations of both the distal interphalangeal (DIP) and proximal interphalangeal (PIP) joints in the same finger that were treated during the past 10 years were classified into three types: the swan-neck injury (dorsal fragment of the base of the distal phalanx at the DIP joint and palmar fragment of the base of the middle phalanx at the PIP joint); the double-hyperextension injury (palmar fragments at the DIP and PIP joints); and the straight-finger injury (with dorsal and palmar bone fragments at the DIP joint). The results of treatment were more satisfactory in PIP joints than in DIP joints.

Fibrous structure and connection surrounding the metacarpophalangeal joint.

The fibrous components of the metacarpophalangeal (MP) joint including the palmar plate, the collateral ligament and the dorsal plate were studied with particular attention paid to the fibrous structure of the fibrous tendon sheath and the deep transverse metacarpal ligament. The tough fibrillar structure around the MP joint, especially the force nucleus, consisted of three types of mixed fibers: the fibrous tendon sheath of the A1 pulley, the deep transverse metacarpal ligament, and the palmar plate. The tendon sheath was located on the ulnar side in the index and middle fingers, on the central position in the ring finger, and on the radial side in the little finger. These fibrous connections among the fingers formed a transverse arch in the hand. The palmar plate of the MP joint was relatively rigid and appears to function as a cushion when flexed. A fold-like protrusion of the synovial layer of the palmar plate of the MP joint had a meniscoid function, which was larger than that of the proximal interphalangeal joint. The capsule of the MP joint was thicker at the dorsal area, forming a dorsal plate, which is a sliding floor of the extensor mechanism and has a meniscoid function for joint congruity. The main lateral stabilizer consisted of collateral ligaments and accessory collateral ligaments anchored to the palmar plate. These structures act together as a "phalangeal cuff", connecting the proximal phalanx to the metacarpal head and stabilizing the MP joint.

The Biodegradation of Low-molecular-weight Urethane Compounds by a Strain of Exophiala jeanselmei.

To further analyze the biodegradation of polyurethane polymers, we investigated the biodegradation of low-molecular-weight N-tolylcarbamate model compounds with structures closely resembling the urethane linkages found in polyurethanes based on tolylene-diisocyanate (TDI). Soil microflora were screened for microorganisms that were able to utilize toluene-2,4-dicarbamic acid, diethyl ester (compound 1) as the sole source of carbon, and the soil fungus Exophiala jeanselmei strain REN-11A was selected as the most effective strain. Several N-tolylcarhamate compounds were used, and it was found that REN-11A was able to degrade compound 1, as well as the related compound toluene-2,6-dicarbamic acid, diethyl ester, very efficiently. Further investigation showed that compound 1 was biodegraded to tolylene-2,4-diamine via the aromatic amine intermediates carbamic acid, (3-amino-4-methylphenyl)-, ethyl ester and carbamic acid, (5-amino-2-methylphenyl)-, ethyl ester.

Comparison of the acute effects of acebutolol and propranolol on blood pressure, heart rate and hormonal changes during graded treadmill exercise in patients with essential hypertension.

The acute effects of propranolol and acebutolol on blood pressure, heart rate and hormonal changes during graded treadmill exercise were studied in patients with essential hypertension. Both of propranolol (2 mg i.v.) and acebutolol (10 mg i.v.) lowered the pre-exercise hemodynamic parameters and suppressed the elevation of systolic blood pressure, heart rate and pressure-rate product during exercise, but did not show any significant effect on diastolic blood pressure. Although these drugs increased plasma norepinephrine concentration (PNE) at rest and during moderate exercise, they failed to affect PNE at submaximal exercise. Plasma renin activity at rest and during exercise were more strongly suppressed by propranolol than acebutolol. Plasma aldosterone concentration was not affected by these drugs. Propranolol and acebutolol showed similar acute effects on blood pressure, heart rate and hormonal profiles at rest and during exercise within the doses used in this study. These results indicate that beta 1 adrenoceptor selectivity and intrinsic sympathomimetic activity may not play an important role in the acute antihypertensive effect at rest and during exercise and that both beta blockers have beneficial antihypertensive effects during exercise on patients with essential hypertension.

Intralymphocytic sodium and free calcium and plasma renin in essential hypertension.

Intracellular sodium, potassium, and free calcium concentrations were investigated in lymphocytes of 30 patients with essential hypertension and 30 normotensive controls. All subjects were placed on a diet containing 8 to 10 g of sodium chloride per day. Lymphocyte sodium concentration was higher in hypertensive patients than in normotensive controls (19.8 +/- 1.8 vs 18.4 +/- 1.8 mmol/kg wet weight; p less than 0.01), whereas lymphocyte potassium concentration was similar in both groups. Lymphocyte free calcium concentration was also higher in hypertensive patients than in normotensive controls (134.6 +/- 13.2 vs 120.2 +/- 16.4 nmol/L; p less than 0.01). There was a positive correlation between lymphocyte sodium and free calcium concentrations in normotensive controls, in hypertensive patients, and in the subjects combined (r = 0.59, p less than 0.01; r = 0.71, p less than 0.001; and r = 0.70, p less than 0.001, respectively). Lymphocyte potassium concentration was not related to lymphocyte sodium or free calcium concentration in each group. In patients with essential hypertension, intracellular sodium and free calcium concentrations were negatively correlated with plasma renin activity (r = -0.66, p less than 0.001; r = -0.60, p less than 0.001, plasma norepinephrine concentration. These results suggest that a considerable relationship exists between intracellular sodium and free calcium in lymphocytes and that, in essential hypertension, the alteration in cellular metabolism of sodium and calcium may be linked to the renin system but not to blood pressure, age, or adrenergic activity.

Electrophysiological effects of propranolol in patients with sinus node dysfunction.

The electrophysiological effects of intravenous propranolol (0.15 mg/kg) were studied in 26 patients with sinus node dysfunction (SND group) and 9 patients with normal sinus node function (control group). Spontaneous cycle length and AH interval were significantly increased in the control and SND groups after propranolol. PA and HV intervals, calculated sinoatrial conduction time and refractory periods of the atrium, AV node and ventricle were not significantly changed in either group. Maximum corrected sinus node recovery time (max CSRT) was not changed in the control group, but it was significantly prolonged in the SND group. These results of the overdrive suppression test were in disagreement with those of previous studies. Propranolol lengthened spontaneous cycle length (by more than 200 msec) and/or max CSRT (by more than 1000 msec) in 8 of 26 patients with SND. Thus, it is suggested that propranolol should be used with caution in patients with SND.

Intracellular sodium concentration in lymphocytes and erythrocytes of patients with essential hypertension.

In order to investigate the abnormalities in intracellular sodium concentration ([Na]i) in essential hypertension, [Na]i in lymphocytes and erythrocytes was determined in 37 outpatients with essential hypertension and 35 normotensive controls matched for sex and age. [Na]i in lymphocytes was higher in hypertensive patients than in normotensive controls, while no difference was observed in [Na]i in erythrocytes between the 2 groups. There was no significant correlation between [Na]i in lymphocytes and erythrocytes in either group. In hypertensive patients, plasma renin activity had a negative correlation with [Na]i in lymphocytes, but not with [Na]i in erythrocytes. These results suggest that the increase in [Na]i may be associated with essential hypertension with suppressed plasma renin activity and that lymphocytes are more suitable than erythrocytes for the analysis of [Na]i.

Intralymphocytic sodium and free calcium concentration in relation to salt sensitivity in patients with essential hypertension.

In order to clarify the relation between salt sensitivity and changes in intracellular sodium ([Na]i) and free calcium concentration ([Ca2+]i) after salt loading, [Na]i and [Ca2+]i were determined in lymphocytes of twenty patients with essential hypertension under a low salt diet (3 g/day) and a high salt diet (20 g/day) for seven days, respectively. They were classified as "salt-sensitive" (n = 10) or "nonsalt-sensitive" (n = 10) on the basis of the changes in blood pressure after salt loading. Both lymphocytic [Na]i and [Ca2+]i were significantly increased with salt loading in salt-sensitive patients (p less than 0.05 for both), while they were not affected by salt loading in nonsalt-sensitive patients. Lymphocytic [Ca2+]i showed a positive correlation with lymphocytic [Na]i under both low salt diet (r = 0.62, p less than 0.01) and high salt diet (r = 0.70, p less than 0.01) in all patients in both groups. In addition, a close and positive correlation was observed between the changes in lymphocytic [Na]i and those in lymphocytic [Ca2+]i after salt loading in all patients in both groups (r = 0.80, p less than 0.001). These results suggest that the increase in [Ca2+]i, possibly linked with the increase in [Na]i, may be involved in elevation of blood pressure in the salt-sensitive patients after salt loading.

Heart rate variability in diabetes: relationship to age and duration of the disease.

Heart rate variability (HRV) during deep breathing was studied with a neonatal heart monitor in 143 control subjects and 218 patients with diabetes (102 with IDDM and 116 with NIDDM). In the control group HRV decreased after age 20 by 4-5 beats per decade (from 29.7 +/- 5.8 beats at age 20-29 to 11.8 +/- 5.4 beats at age 60+). In all age groups HRV in IDDM was lower than in the controls, and both age and duration of diabetes played a role in the decrease of HRV (from 21.5 +/- 5.3 beats at age 20-29 to 6.3 +/- 5.4 at age 60+). In NIDDM aging seemed to play a less important role, and the influence of the duration of the disease was not statistically significant. In both groups of patients the frequency of HRV below the 2.5th percentile was 82% in those with symptoms and/or signs of autonomic neuropathy, 64% in patients with peripheral neuropathy only, and 36% in those who had no obvious signs or symptoms of neuropathy. Interindividual variability was pronounced, and age and duration of the disease together accounted for only 36% of the observed differences between IDDM and the controls. Determination of HRV with a standard neonatal heart monitor presents an easy, simple, and nonstressful test of cardiac autonomic neuropathy. The norms of the test are age related.

Therapeutic effects of tracheostomy in two cases of hypersomnia with respiratory disturbance during sleep.

Recently the association of hypersomnia and respiratory insufficiency without lesion in the respiratory organ has attracted attention of many investigators. Obese patients with such a condition have been called the Pickwickian syndrome. In this report, two non-obese patients with a similar condition were presented, one with micrognathia and frequent apneic episodes during sleep, and the other with laryngeal stenosis due to paralysis of the bilateral laryngeal nerves and chronic laryngitis. Tracheostomy had a prompt and long-lasting therapeutic effect to make their sleep stable and also to relieve their excessive daytime sleepiness. These findings suggest that the obstruction or stenosis of the upper airway during sleep disturbed their nocturnal sleep, and that their excessive daytime sleepiness was a phenomenon compensating for their disturbed nocturnal sleep.

Sleep satiation in narcoleptic patients.

UNLABELLED: Polygraphic sleep recording was performed in 20 narcoleptics with one or more of the auxiliary symptoms, 4 narcoleptics with only sleep attacks and 10 normals during one night and into the following day. Total sleep time in the narcoleptics did not differ significantly from that in the normals. Sleep of the narcoleptics with auxiliary symptoms was unstable with frequent awakening. The temporal organization of the REM--NREM sleep cycle was irregular in the narcoleptics with auxiliary symptoms, compared with those in the other two groups. Percentage of Stage 1 was significantly larger in the narcoleptics with auxiliary symptoms than in the other two groups and percentage of Stage 2 was smaller. Percentage of Stage 4 was smaller in the narcoleptics with auxiliary symptoms than in those with only sleep attacks. Percentages of Stages 3 and REM did not differentiate the three groups. Spindle density during Stage 2 did not differentiate the three groups. Sleep onset Stage REM was frequently observed exclusively in the narcoleptics with auxiliary symptoms. Excluding the instances showing sleep onset Stage REM, mean latency of initial episodes of REM sleep in the three groups was shorter after daytime sleep onset than after nighttime sleep onset. In the narcoleptics with auxiliary symptoms, no significant correlation was found between the percentage of Stage REM and clinical findings. CONCLUSIONS: the sleep attacks in narcoleptics are due to an ill-timed, strong tendency to fall asleep (including both REM and NREM sleep), and it is therefore suggested that they are manifestations of their disturbed circadian rhythm of sleep--wakefulness cycle.