Transverse divergent dislocation of the elbow. A report of two cases

Two children with transverse divergent dislocation of the elbow had quick and complete recovery following closed reduction and immobilisation.

Nonpulsatile cardiopulmonary bypass disrupts the flow-metabolism couple in the brain

The effect of cardiopulmonary bypass on the relationship between brain glucose consumption and regional blood flow is unknown. We measured this relationship in pigs subjected to 3 hours of pulsatile or nonpulsatile cardiopulmonary bypass at normothermia and compared the results to the relationship established in a control group of pigs. A total of 10 regions were sampled in both hemispheres of the porcine brain. In control pigs, cerebral blood flow averaged 46 ml/100 gm and the glucose consumption, 21 mumol/100 gm/min. The ratio between blood flow and glucose consumption was close to 2 ml/mumol in all regions. In pulsatile cardiopulmonary bypass both the whole-brain average and the regional values declined, so that the ratio remained the same, about 2 ml/mumol. In nonpulsatile cardiopulmonary bypass regional blood flow remained normal; the average was 49 ml/100 gm/min, whereas the average glucose consumption declined to 16 mumol/100 gm. In regions with high blood flow rates, the ratio between blood flow and glucose consumption increased to about 3 ml/mumol, indicating perfusion in excess of metabolic demand. We conclude that nonpulsatile cardiopulmonary bypass at normothermia affects the metabolic flow regulation in the brain by interfering with the myogenic contractility of cerebral arterioles.

Dislocation of the superior tibiofibular joint

Derangements of the superior tibiofibular joint are divided into anterolateral, posteromedial and superior dislocations and chronic instability. Two cases of anterolateral dislocation, both needing open reduction, are presented together with a case of posteromedial dislocation.

Experimental measurement of rotatory and translatory instability of the knee joint

In the evaluation and treatment of knee ligament injuries and for comprehensive understanding of knee ligament function, it is important to know where in the movement of extension-flexion the different types of instability released by wellknown ligament injuries occur. An apparatus was developed to record anterior– posterior tibial displacement, valgus–varus instability, and axial tibial rotation instability on knee preparations, continuously, in the extension–flexion movement, when the tibia was submitted to a well-defined constant torque or force. Osteoligamentous knee preparations were suspended in the femur and a lever was fixed to the tibial segment. The lever was fitted with strain gauges to measure the torque in three planes. Potentiometers recording extension–flexion, anterior–posterior tibial displacement, valgus–varus, and axial rotation angulations were mounted. The lever was moved manually, and signals from strain gauges and potentiometers passed through an amplifier and a data acquisition system to a microcomputer, which stored the results of the measurements. The final movement curves were calculated and plotted at a regional computer service centre. Tests for reproducibility of measurements at different ligament status demonstrated a high level of reproducibility.

Pulsatile flow during cardiopulmonary bypass. Evaluation of a new pulsatile pump

Pulsatile cardiopulmonary bypass (CPB) has been suggested to be superior to nonpulsatile CPB. This report concerns a newly developed pulsatile pump for clinical use. It is designed as a positive displacement pump, with blood allowed to collect in a valved cavity from which it is ejected by the reciprocating action of a piston. Using a uniform procedure of anaesthesia and surgery, 14 pigs were subjected to CPB at 37 degrees C for 3 hours. The pulsatile pump was used in seven pigs and a conventional roller pump in the other seven. The wave-form of the pulse during pulsatile CPB was similar to that recorded in the pigs before bypass. The values for rate of pressure change with respect to time (dp/dt) obtained in the aorta were close to the pre-CPB values. No difference was found between the two groups with respect to platelet count or haemolysis. The investigated pulsatile device appeared to be reliable and easy to handle, and the pulsation it produced closely resembled the physiologic pulse-wave form.

Peripheral neuropathy, cerebral atrophy, and intellectual impairment in chronic alcoholics

Peripheral neuropathy, cerebral atrophy, and intellectual impairment was investigated in 46 males with alcoholic nervous system damage. An overall correlation was found between peripheral neuropathy and cerebral atrophy and between several of the individual neurophysiological and neuroradiological variables examined. There was also a correlation between cerebral atrophy and intellectual impairment. The findings support the view that alcohol in itself is toxic to central and peripheral nervous tissues, although a dose-response dependence could not be established.

Construction and use of a gene bank of Alcaligenes eutrophus in the analysis of ribulose bisphosphate carboxylase genes

A gene bank of the DNA from the hydrogen bacterium Alcaligenes eutrophus ATCC 17707 was constructed in the broad host range cosmid vector pVK102 and established in Escherichia coli. A triparental replica plating procedure was developed to allow rapid screening of large numbers of isolated E. coli gene bank clones for complementation of A. eutrophus mutants. This procedure was used to identify hybrid cosmids that complemented CO2 fixation-negative (Cfx-), H2 uptake-negative (Hup-), and auxotrophic A. eutrophus mutants. The average insert DNA size in these hybrid cosmids was 22 kilobases. Nine hybrid cosmids that complemented ribulose bisphosphate carboxylase-negative (RuBPCase-) mutants were characterized. They fell into two distinct groups with respect to their restriction patterns. Complementing subclones from the two groups contained no common restriction fragments, but hybridization experiments indicated a high degree of sequence homology. Restriction fragments corresponding to one of the subclones were absent in total DNA from a cured strain that had lost plasmid pAE7, indigenous to the wild type. It is concluded that functional CO2 fixation genes in the A. eutrophus ATCC 17707 chromosome are reiterated on plasmid pAE7.

Rotatory instability of cadaver knees after transection of collateral ligaments and capsule

The importance of the medial and lateral compartment ligaments of the knee in relation to valgus-varus and axial rotation instability was investigated. Mobility patterns were drawn from 20 osteoligamentous knee preparations after successive transections of the structures. Cutting of the medial collateral ligament resulted only in slight valgus instability and modest anteromedial instability. When the medial posterior joint capsule was also cut, both types of instability increased, and moreover, the knee became posteromedially unstable. Cutting of the lateral collateral ligament produced only a little varus instability and anterolateral rotatory instability, but varus instability increased considerably when the posterior lateral capsule was also transected. In this latter situation, even marked posterolateral rotatory instability was found. Isolated transection of the medial or lateral collateral ligament did not cause any major valgus or varus instability, but when the posterior capsule was also transected, a considerable degree rotatory instability could be found even though the cruciate ligaments were intact.

The development of simple acoustic reaction time in normal children

Normative data on the simple acoustic reaction time were obtained from 56 children without neurological or psychiatric symptoms aged between four and 14 years, and the results were compared with those for an adult reference group. Mean reaction times declined precipitously from 465 msec at age five to 190 msec at 15 years. The relationship between reaction time and age during childhood can be described by a linear equation in a log-log system. The adult level is achieved at 16 years.

T lymphocyte subsets in homosexual men from Copenhagen

Screening of sixty-six asymptomatic homosexual men from Copenhagen revealed significantly lower Leu-3a/Leu-2a ratios as compared to controls. Ten (15%) of the homosexuals had a ratio less than or equal to 1.0. The low Leu-3a/Leu-2a ratios were the result of an increase in the absolute number of Leu-2a cells. Homosexuals with many partners and those who had been sexual partners of patients with the acquired immuno-deficiency syndrome (AIDS) had significantly lower ratios than those without these features. Cytomegalovirus was isolated from urine and/or sputum of 15% and this was associated with a Leu-3a/Leu-2a ratio less than or equal to 1.0. The observed immunological abnormalities could either represent latent infection with the putative AIDS agent or alternatively be caused by repeated infections and/or exposure to allogenic spermatocytes or lymphocytes.

Sympathetic vasoconstrictor nerve function in alcoholic neuropathy

The peripheral sympathetic vasomotor nerve function was investigated in 18 male chronic alcoholics admitted for intellectual impairment or polyneuropathy. By means of the local 133Xenon washout technique, the sympathetic veno-arteriolar axon-reflex was studied. This normally is responsible for a 50% decrease in tissue blood flow, when the ankle is lowered 40 cm below heart level in the supine individual. The patients with moderate to severe polyneuropathy, taken as a group, did not differ significantly from the group of patients with no or only mild polyneuropathy, although a lesser response was seen (18% and 48% decrease respectively). However, in three patients with moderate neuropathy, and in one patient with no signs of neuropathy, this veno-arteriolar reflex was absent, indicating dysfunction of the peripheral sympathetic adrenergic nerve fibres. The three patients also showed a lesser degree of arteriolar constriction during 45 degrees passive head-up tilt, although none developed symptoms of orthostatic hypotension. Anhidrosis of the feet was found in only three patients. This study lends support to the view that individual differences in the susceptibility to the deleterious effect of alcohol comprise not only the peripheral sensory and motor nerve fibres, but also the thin pseudomotor and vasomotor nerves.

Effects of spontaneous respiration on left ventricular function assessed by echocardiography

The effects of quiet respiration on assessment of left ventricular function by two-dimensional echocardiography were investigated in 12 healthy men. End-diastolic area in the parasternal short-axis view decreased with inspiration (from 17.3 +/- 2.1 [mean +/- SD] to 16.0 +/- 2.1 cm2, p less than .01), while end-systolic area did not change (from 7.6 +/- 1.4 to 7.7 +/- 1.5 cm2; NS). A fixed cursor that was located through the center of the left ventricular area at end-expiration made a tangential cut of the area at end-inspiration were smaller along the cursor than through the center of the short-axis area both at end-diastole (1.9 +/- 1.7 mm; p less than .01) and end-systole (3.8 +/- 4.0 mm; p less than .01). Our results suggest a need for standardization with regard to respiratory phases in assessment of left ventricular function by two-dimensional echocardiography and indicate the occurrence of inspiratory reduction of left ventricular stroke volume associated with decreased diastolic filling. Motion of the heart relative to the echo beam may play a part in the respiratory variations in left ventricular dimensions assessed by M mode echocardiography.

Increased left ventricular emptying at maximal exercise after reduction in afterload

Twelve healthy men were studied by M mode echocardiography during exercise to investigate the effect of afterload reduction on left ventricular function at maximal exertion. They performed two maximal exercise bicycle tests 4 hr apart while in the semisupine position and were given 20 mg nifedipine sublingually 30 min before the second test. During the first test end-systolic dimension decreased (p less than .01) and fractional shortening increased from rest to peak exercise (p less than .01), while end-diastolic dimension did not change significantly. At maximal exercise systolic blood pressure was lower after nifedipine than in the preceding control test (202 +/- 10 [mean +/- SD] vs 212 +/- 14 mm Hg; p less than .01), while heart rate was not significantly changed (168 +/- 15 vs 162 +/- 13 beats/min). End-systolic dimension was lower (25.6 +/- 3.3 vs 28.8 +/- 4.2 mm; p less than .01) and fractional shortening higher (50.7 +/- 6.0% vs 45.3 +/- 7.0%; p less than .01) while end-diastolic dimension was unchanged (52.3 +/- 1.9 vs 52.4 +/- 2.6 mm). Our data indicate increased left ventricular emptying at maximal exercise after nifedipine, most probably due to reduction in afterload.

Instability of cadaver knees after transection of capsule and ligaments

The importance of the medial collateral ligament and the anterior cruciate ligament of the knee in relation to valgus and varus instability was investigated. Mobility patterns were drawn from ten osteoligamentous knee preparations after successive transections of the structures. Cutting the entire collateral medial ligament caused only slight valgus instability, even when the knee was flexed. Further transection of the anterior cruciate ligament increased the instability considerably, but the knee remained stable in extension. The valgus instability after the transections was maximal at about 60 degrees of flexion.