The effects of intervertebral fusion in patients with myelopathy due to ossification of the posterior longitudinal ligament of the cervical spine

Fifty patients with ossification of the posterior longitudinal ligament of the cervical spine were treated by anterior intervertebral body fusion and compared with 30 other patients treated conservatively. We found that patients with narrowing of the cervical canal to 0.5 of the normal diameter were improved by simple intervertebral fusion without excision of the ossified ligament. Patients with more extensive ossification and narrowing of the spinal canal to less than 0.4 of the normal diameter might have either severe symptoms or unexpectedly minor symptoms and the latter were attributed to the spontaneous fusion and loss of mobility that had occurred. Conversely, patients with less severe ossification but abnormally increased intervertebral mobility often had severe symptoms but were greatly improved following intervertebral fusion. It was concluded that narrowing of the spinal canal in the presence of mobility of the neck produced unfavourable dynamic compression of the spinal cord and that reduction in the mobility of the spine was effective in reversing many of the signs of cervical myelopathy.

[Evaluation of estimation method of X-ray spectral distribution by attenuation data (author's transl)]

This paper describes a method for estimating spectral distributions from X-ray attenuation data obtained by inserting metal filters in the beam. First, the principle of the estimation method is briefly outlined. the spectral distribution is approximated by a histogram with an appropriate number of cells whose heights are estimated by recursive algorithm. The algorithm is based on a gradient method that seeks the minimum of a least-square criterion function. Next, the following two problems to which special attention should be paid in practical applications are discussed: 1) appearance of discontinuity in estimated distribution; and 2) termination criterion of iterative computation. The problem 1) is investigated theoretically and the improved algorithm is devised. Computer simulation is performed for the problem 2), and a proper termination criterion based on the decreasing curve of the least-square criterion function is given. The validity of estimation results is illustrated about the spectral distribution of 140 kV constant potential X-ray source.

Malfunction of a Björk-Shiley mitral valve prosthesis due to excessive platelet-fibrin deposition on its sewing cuff. A case report

A Bjork-Shiley mitral valve prosthesis had to be replaced 4 years after implantation because of disc entrapment by an over-grown fibrous tissue on its sewing cuff. This abnormal fibrous tissue was found out to be an organizing platelet-fibrin deposit, of which luminal surface was only incompletely endothelialized. It is indicated that the heart valve prosthesis generally remains non-endothelialized for a prolonged period of time after implantation in man. Anticoagulation therapy should thus be given throughout the postoperative period for patients with the heart valve prosthesis.

Adenosine release during early and sustained exercise of canine skeletal muscle

During contraction of skeletal muscle in the isolated dog hindlimb under constant-flow perfusion, the specific activity of infused [8- 14C]adenosine (nonvasoactive concn) in venous effluents decreased to 7% of the resting level in 1.25 min and was associated with a concomitant decrease in vascular resistance to 39% of the resting value. Since this decrease in specific activity of labeled adenosine could have been due to 1) an enhanced adenosine release by parenchymal tissue, 2) an exercise-induced increase in the number of open capillaries (greater surface area) in the absence of increased adenosine production 3) some degree of tissue hypoxia, or 4) a combination of these factors, experiments with maximally dilated vessels were performed. Acetylcholine and a nonvasoactive concentration of [8- 14C]adenosine were continuously infused into an isolated dog hindlimb which was perfused at constant flow during periods of rest, contraction, and recovery while arterial oxygenation was maintained at normoxic levels. Approximately 2.75 min after the onset of contraction with the vascular bed maximally dilated, the specific activity of [8- 14C]adenosine in venous effluents decreased to 38% of the resting level while the venous Po2 decreased from 78 to 42 mmHg; the value of 42 mmHg indicates apparent absence of hypoxia in the muscle. These observations are consistent with the concept that adenosine release is involved in the vasodilation observed in contraction of skeletal muscle.

Epidemiologic aspects of biliary tract cancer in Japan

According to the vital statistics accumulated in Japan from 1958 to 1975, the mortality of biliary tract cancer 1) is low under age 50 and thereafter increases in parallel with age and reaches its peak in the eighth decade; 2) is higher among females than males (especially gallbladder cancer), but cancer of the bile ducts predominates in males; 3) has shown an increasing trend in recent years (1958-75), especially among older persons; and 4) varies geographically. Mortality from this disease is particularly high in the northern parts of Honshu (the main island). Correlation analyses and a factor analysis between food consumption (1964) and the mortality from biliary tract cancer (1972-74) for 46 prefectures in Japan revealed that although expenditures for some foods (dried noodles and pork) are possibly related to the mortality rate of biliary tract cancer, expenditures for others (fat and protein-rich western-type foods) are negatively associated with this cancer. These possible associations need further clarification by more refined epidemiologic and laboratory studies. Possible effects of diagnostic procedures or techniques on secular trends and geographical distribution are also discussed.

[Changes in plasma dopamine-beta-hydroxylase activity in patients with acute subarachnoid hemorrhage (author's transl)]

In 24 patients with subarachnoid hemorrhage (SAH) who were admitted within 48 hours after the onset, the activity of dopamine-beta-hydroxylase (DBH) in peripheral venous plasma was analyzed applying the method described by Nagatsu and Udenfriend (Clin. Chem., 18: 980-983, 1972) with a minor modification. Plasma samples were serially collected every a few days for three days to four weeks after the onset. DBH activity in peripheral venous plasma increased markedly after the onset, reaching the highest level within 48 hours, and thereafter declined time-dependently for about two weeks. There was no significant difference in the plasma DBH activities on admission between patients with and without cerebrovascular spasm revealed by angiography. The decline of the activity was significantly remarkable in patients with spasm compared with those without spasm. The difference was most prominent around the 7th day after the onset when spasm was shown most frequently. Neurosurgery or administration of analgesics and/or sedatives had little effect on the changes in plasma DBH activity in acute SAH. The activity correlated with the pressure of cerebrospinal fluid (r = 0.587, P less than 0.05), when it was higher than the normal range. With these results we obtained following: 1) The activity of sympathetic nervous system increases following SAH for a week after the onset. 2) The activity declines more rapidly in patients with cerebrovascular spasm than those without spasm, when it was judged from the activity of plasma DBH activity.

Lung cancer involving the superior vena cava: pneumonectomy with concomitant partial resection of superior vena cava

We report two cases in which partial resection and reconstruction of the superior vena cava (SVC) were performed with the use of a temporary SVC-right atrial internal bypass for complete resection of carcinoma of the right lung. In the first case, the SVC was invaded by the primary tumor itself, arising in the anterior segment of the right upper lobe. In the second case a metastasized tracheobronchial lymph node had invaded the SVC. In both cases, partial resection of SVC was performed safely with the internal bypass technique.

[Simplification of gamma-ray spectral data by using Fourier transform]

A method is proposed to represent gamma-ray response spectra by Fourier series for the purpose of compressing spectral data. The usefulness of the method was confirmed by applying it to a spectral library of a NaI detector. In the method, a response spectrum as a wave is described by superposition of sine (cosine) waves with low frequencies, whose coefficient parameters can be obtained by a Fast Fourier Transform program. The relation between the number of parameters and the fitting error is discussed, and as the result, it is shown that the number of parameters can be reduced to about a half. The merits and features are presented in practical application of the method to the analysis of gamma-ray spectra.

[Analysis of gamma-ray spectra by using fast Fourier transform (author's transl)]

In order to simplify the mass data processing in a response matrix method for gamma-ray spectral analysis, a method using a Fast Fourier Transform devised. The validity of the method was confirmed by a computer simulation for spectra of a NaI detector. The method uses the fact that spectral data can be represented by Fourier series with reduced number of terms. The estimation of intensities of gamma-ray components is performed by a matrix operation using the compressed data of an observation spectrum and standard spectra in Fourier coefficients. The identification of gamma-ray energies is also easy. Several features in the method and a general problem to be solved in a response matrix method are described.

Bone grafts with microvascular anastomoses of vascular pedicles: an experimental study in dogs

Using microvascular anastomoses of artery and vein, bone grafts with vascular pedicles from the rib were transferred to inlay and bridge defects in the femora of forty-two dogs. The osteocytes of the pedicle graft were not affected, and neither necrosis nor creeping substitution occurred in the grafted bone. The pedicle bone grafts united to the recipient bed earlier than did the non-pedicle bone grafts, and the rate of non-union of the pedicle bone grafts was lower than that of the non-pedicle grafts.

Venous plasma cyclic AMP in acute cerebrovascular disease

Antecubital venous blood was sampled from stroke patients in the presence of disodium ethylenediamine tetraacetate. Plasma was analyzed for cyclic AMP applying a competitive protein binding method without any special pretreatment. In mild hemispheric infarction as manifested by moderate hemiparesis and/or dysarthria, plasma cyclic AMP remained in the normal range (8-18 picomoles/ml). In most of the cases with moderate infarction, the cyclic AMP level was distinctly below the normal range several days after the onset of symptoms. However, cyclic AMP remained in the normal range in severe infarction with signs of brain edema, and in two cases with moderately severe symptoms. One of the two cases suffered from later development of brain edema, and the other revealed a large lesion in brain scintigrams. The sizes of the lesion revealed in brain scintigrams were smaller in the moderate cases and larger in the severe cases, except in one of the cases mentioned above. It appeared that with plasma cyclic AMP levels we could predict the extent of the lesion, and perhaps the subsequent development of impending brain edema in a few days after the onset of cerebral infarction. In moderate cases of cerebral hemorrhage, judged from the consciousness, cyclic AMP decreased to a subnormal level 2-4 days after the onset. In severe cases it remained in the normal range. Subarachnoid hemorrhage showed significantly elevated cyclic AMP levels in the early stage.

Cerebrovascular CO2 reactivity in normotensive and hypertensive man

Cerebrovascular reactivity to CO2 inhalation and voluntary hyperventilation was studied in seven normotensive subjects and nine hypertensive patients without clinical or angiographical signs of arteriosclerosis. Cerebral blood flow (CBF) was measured by the intracarotid 133Xe clearance method and calculated as the initial slope index. Three to five CBF measurements were made in each patient in the PaCO2 range of 20 to 55 mm Hg. No difference was observed in reactivity between hypertensive and normotensive patients, either during CO2 inhalation or during hyperventilation. The shape of the CBF:PaCO2 curve suggested a decrease in reactivity below a PaCO2 of 30 to 35 mm Hg in both groups. Above a PaCO2 of 35 mm Hg, exponential regression analysis yielded a mean reactivity of 6 +/- 2%, whereas below a PaCO2 of 30 mm Hg it was about 2%. The rise in CBF during CO2 inhalation was not influenced by the intravenous infusion of a small dose of trimethaphan which blocked the concomitant rise in blood pressure.

Role of adenosine or AMP as a probable mediator of blood flow regulation in canine hindlimb muscles

Canine hindlimb muscles were perfused with arterial blood from a donor at a constant pressure or at a constant flow rate. Blood samples were analyzed for adenosine, oxygen and potassium during load-free twitch contractions (2 cps) and/or after 3-min ischemia. (1) During exercise hyperemia A-V oxygen (p smaller than 0.001) and V-A potassium (p smaller than 0.001) differences increased in both perfusion systems. Under the constant pressure total amount of adenosine and/or AMP released (TAAR) remained constant at 34.4 plus or minus 7.8 (mean plus or minus S.D.) nmoles/ml of blood compared with 31.0 plus or minus 5.6 at rest, whereas under the constant flow rate the value increased from 32.8 plus or minus 9.4 to 74.6 plus or minus 15.7 (p smaller than 0.001). (2) In reactive hyperemia A-V difference of oxygen increased (p smaller than 0.001) and TAAR remained at 33.0 plus or minus 8.3 under the constant pressure. Under the constant flow rate TAAR increased from 32.8 plus or minus 9.4 to 48.1 plus or minus 12.6 (p smaller than 0.001). (3) After ischemic contractions TAAR remained constant under the constant pressure perfusion. Under the constant flow rate, however, TAAR showed definite decrease compared with that during exercise hyperemia with intact flow (p smaller than 0.001). (4) The authors think that adenosine and/or AMP is the mediator of exercise hyperemia, supported by potassium ions and local hypoxia. Adenosine and/or AMP, and local hypoxia are responsible for reactive hyperemia. In ischemic contractions, no special circulatory mediator was found.

Mode of action of colistin

The prophylactic efficacy of isoprinosine was evaluated in a double-blind fashion in volunteers challenged with two types of rhinovirus. In the rhinovirus 44 and 32 trials, each of 9 men received a placebo, and eight and 11 men received the drug, respectively. Oral isoprinosine, 6 g a day, was given for 2 days prior to intranasal challenge with 100 mean tissue culture infective doses of the virus and for 7 postchallenge days. In both trials the occurrence and severity of colds were greater in the placebo group, but the difference between the two groups was not significant. Higher antibody titers for both viruses and a greater number of rhinovirus 32 isolations were demonstrated in the drug group but without statistically significant differences. The prophylactic isoprinosine treatment may suppress the cold syndrome, but its effect was not convincingly apparent.

Prognostic significance of ventricular ectopic beats with respect to sudden death in the late postinfarction period

The role of ventricular dysrhythmias as determinants of sudden coronary death (SCD) was studied prospectively in 160 male survivors of myocardial infarction, all under 65 years of age and in New York Heart Association (NYHA) functional class I or II. Twelve-hour electrocardiographic recordings were taken in all patients at serial intervals and analyzed for frequency and type of ventricular ectopic beat (VEB). Eighty percent showed VEB's on at least one tape recording. There have been 14 SCD's in a follow-up period ranging between 30 and 54 months, 12 in 87 patients (13.8%) with significant VEB's (frequent, unifocal, multifocal, paired or coupled, and ventricular tachycardia), and only two in 66 patients (3%) with absent or infrequent VEB's ( P < 0.02).

Although the number of patients in this study is small, the results show that all complex VEB forms together were associated with an excess risk of SCD, notwithstanding the absence of SCD in 27 patients with ventricular parasystole. It is suggested that the differential association with SCD between ventricular extrasystoles and parasystole in the late postinfarction period may have bearing on the mechanism of ventricular fibrillation and SCD.