Preservation of skeletal muscle in tissue transfers using rat hindlimbs.

Replantation of major extremities after long periods of ischemia can lead to viable replants in many cases, but functional restoration is often poor owing to fibrosis of the muscle. In this study, maximum hypothermic time in tissue transfers containing skeletal muscle using hindlimbs of Lewis rats preserved in 4 degrees C Euro-Collins solution was investigated. After preserving midthigh amputated legs in this solution for 6, 9, and 12 hours, the legs were transplanted to other inbred rats using microsurgical technique, and 1 week later, gastrocnemii were obtained to analyze ATP, ADP, and AMP using high-performance liquid chromatography. The values were compared with those for healthy legs, nonischemic operated control legs, and legs preserved in the same manner for 6, 9, and 12 hours. Histologic and serologic examinations were conducted. ATP values of the 9-hour preservation group resumed those of the nonischemic operated control group, with the values of the 12-hour preservation group remaining at 61 percent. Histologically, focal necrosis, hyaline degeneration, and regeneration processes were the most characteristic manifestations in the muscles transplanted after cold ischemia of 12 hours. It was concluded that skeletal muscle could be preserved for 9 hours in 4 degrees C Euro-Collins solution.

Carpal kinematics of lunotriquetral dissociations.

The purpose of this study is to investigate the carpal kinematics after serial arthroscopic sectioning of the ligaments at the lunotriquetral joint, without damaging the capsule and other soft tissues of the wrist. Six cadaver wrists were studied and a custom designed three-dimensional mechanical digitizer was utilized. Three sets of digitization were performed for a normal state, after arthroscopic sectioning of lunotriquetral interosseous ligament (stage A), and after further sectioning of volar radiolunotriquetral ligament (stage B). Motion of the scaphoid, lunate, triquetrum, capitate and hamate was studied. The results indicated that the motion of the triquetrum was significantly increased at stage A, particularly after 15 degrees of ulnar deviation. An increased motion at the lunotriquetral joint was observed at stage B, which was mainly due to the significantly decreased lunate extension motion and the increased triquetrum extension motion during wrist extension. This study suggested that the lunotriquetral interosseous ligament plays the most important role for the stabilization of the lunotriquetral joint during wrist ulnar deviation, while the volar radiolunotriquetral ligament may function as a stabilizer for the lunotriquetral joint during wrist extension.

Effects of calmodulin antagonists on calcium-activated potassium channels in pregnant rat myometrium.

1. The effects of W-7, trifluoperazine, and W-5 on Ca2(+)-activated K(+)-channels were investigated with the inside-out patch-clamp method in smooth muscle cells freshly dispersed from pregnant rat myometrium. These drugs are known to have different potencies as calmodulin antagonists. 2. In the presence of 1 microM Ca2+ on the cytoplasmic side ([Ca2+]i), the fraction of time the channel was open (open probability, Po) was about 0.9 and the calmodulin antagonists (1-30 microM) applied to the cytoplasmic face reduced Po to 0.65-0.55 dose-dependently. In the presence of 0.1-0.16 microM Ca2+, when Po was very low (0.02), calmodulin antagonists increased Po. All antagonists used produced almost identical effects at the same concentration. 3. The probability density function of the open time distribution could be described by the sum of two exponentials. W-7 decreased the time constant of slow component of distribution and at 30 microM the slow component disappeared both at 1 and 0.25 microM [Ca2+]i, reflecting the appearance of flickering channel activity. The probability density function of the closed time distribution could be fitted with three exponentials. The time constants of these components were not significantly altered by W-7. 4. Internally applied calmodulin (1-5 microM) did not produce any significant effect on channel activity. 5. The effects of calmodulin antagonists are considered to be due to a direct action of these compounds on the channel, and suggest that channel activation by Ca2+ is not mediated by calmodulin.

Contracture caused by sodium removal in the pregnant rat myometrium.

The contracture produced by removal of the external Na was studied in the pregnant rat myometrium and this was compared with that of the non-pregnant myometrium. The Na-free contracture was small compared with spontaneous phasic contractions in the circular muscle of non-pregnant rat, but the contracture increased during pregnancy. On the other hand, in the longitudinal muscle, the contracture was large in both non-pregnant and pregnant myometria. The change in circular muscle did not seem to result from an increased sensitivity to the external Ca. Since the contracture induced by 40 mM K had properties similar to those of the Na-free contracture, it is likely that weak tension development in non-pregnant circular muscle is either due to a limited Ca influx or due to a low efficiency of the excitation-contraction coupling for the sustained contraction compared with the phasic contraction. A small contraction which was independent of the external Ca was observed in Na-free solution in the both layers of non-pregnant myometrium, but this was not observed in the longitudinal muscle of pregnant myometrium.

Maternal liver impairment associated with prolonged high-dose administration of terbutaline for premature labor.

Widespread use of beta 2-sympathomimetic therapy for premature labor has resulted in a diverse number of serious maternal complications, ie, pulmonary edema, myocardial ischemia, etc. However, to the authors' knowledge, there has been only one previous report of mild maternal liver impairment associated with this therapy. Recently, a patient developed marked elevation of liver enzymes (serum glutamic oxaloacetic transaminase, serum glutamic pyruvic transaminase) during therapy with terbutaline sulfate for premature labor.

[Effects of iontophoretically-applied LHRH, TRH, estrogen and clomiphene on thermo-sensitive neurons in the rat hypothalamus].

Studies were performed on the correlation between the hypothalamic temperature-sensitive neurons and hypothalamic neurons sensitive to LHRH, TRH, conjugated estrogen and clomiphene in 103 castrated matured female rats by the technique of microiontophoresis using a multi-barrel glass microelectrode. Out of 348 neurons in the hypothalamus, 24 neurons were found to be LHRH-sensitive, 20 TRH-sensitive, 41 estrogen-sensitive, and 18 clomiphene-sensitive. There were 19(28.8%) warm-sensitive and 11(16.7%) cold-sensitive neurons located in the preoptic area. From among the 19 warm-sensitive neurons, 14 neurons showed excitation by estrogen and 4 showed suppression by LHRH. Out of the 11 cold-sensitive neurons, estrogen, LHRH, and TRH excited 4, 3, and 3 neurons, respectively. It is suggested from these studies that LHRH mainly exhibits its thermo-regulatory functions by exciting warm-sensitive neurons and it is for this reason that exogenous estrogens are effective in alleviating hot flushes in natural as well as post-operative menopause which are thought to be caused by LHRH.

Effects of prostacyclin on fetal platelet function.

Prostacyclin (PGI2), the major active metabolite of arachidonic acid in the vascular endothelium, is characterized by antiaggregatory and vasodilator properties. In this report the significance of PGI2 on fetal platelets was studied. Platelet aggregation induced by ADP, collagen, and adrenaline was found to be augmented in maternal blood but suppressed in umbilical cord blood. The plasma beta-thromboglobulin levels were higher in maternal and umbilical cord blood compared with that of a control group. Plasma 6-keto-PGF1 alpha, TxB2, cyclic AMP, and cyclic GMP values were significantly higher in umbilical cord blood than in maternal blood. A much larger amount of PGI2-like substance was released from the umbilical vessels than from the placental vascular tissues. The generation of this substance was reduced in the umbilical vessels in patients with severe pre-eclampsia associated with intrauterine fetal growth retardation. These results indicate that various factors, such as PGI2, TxA2, and cyclic nucleotides, may co-exist at high levels in the fetus. A balance is needed to maintain physical interaction between platelets and the vascular wall in the fetal blood vessels. Especially PGI2 may play an important role in this balance and in the regulation of the placental-fetal circulation.

[Metabolic significance of cyclic nucleotides in the environment for fetal growth--effects of PGI2-like substance on fetal platelet function].

Prostacyclin (PGI2), the major active metabolite of arachidonic acid in the vascular endothelium, is characterized by antiaggregatory and vasodilator properties. In this report, the significance of PGI2 and TxA2 on fetal platelets was studied. Platelet aggregation induced by ADP, collagen and adrenalin were found to be augmented in maternal blood but suppressed in umbilical cord blood. A much larger amount of PGI2-like substance was released from the umbilical cord artery and vein than from the intraplacental vein and chorionic tissue. On the other hand, the generation of this substance was reduced in the umbilical cord artery (4.4 +/- 2.7 nmoles/mg tissue/hour) and vein (2.9 +/- 2.1 nmoles/mg/tissue/hour) in patients with severe pre-eclampsia associated with IUGR. The plasma beta-thromboglobulin level is higher in maternal and umbilical cord blood, than in control group. Plasma 6-Keto-PGF1 alpha, TxB2, cyclic AMP and cyclic GMP values were significantly (p less than 0.05) higher in umbilical cord blood than in maternal blood, but serum phosphodiesterase activity showed no difference between mother and fetus. These results indicate that various factors, such as PGI2, TxA2 and cyclic nucleotides, may co-exist in high levels in the fetus, and the balance is needed for the maintenance of physical interaction between the platelet and vascular wall in the fetal blood vessels. PGI2 in particular may play an important role in this balance and in the regulation of placental-fetal circulation.

[Compliance of brain--Part 2 Approach from the local elastic and viscous moduli (author's transl)].

It is important to have information about physical property of the brain in order to elucidate both the physical changes of the morbid brain and the physical mechanism of the traumatic brain injury. Under the hypothesis that reaction of the active brain to the dynamic load can be compared to the Maxwell-Voigt three dimensional model, elastic property of the brain was obtained as the Young's modulus (E: 10(-2) Kgf/cm2) of which error was less than 10%, and viscous property of the brain as the Viscous modulus (eta: 10(-2) Kgf.sec/cm2). And it was confirmed that the reactive pressure of the brain to dynamic load came from the surface to about 15 mm depth of the brain. In this report, experiments were done on the alive normal brains, the edematous ones nd necrotic ones which were produced by the cold injury (dry ice-aceton) in dogs (9.0--16.0 Kg). In the normal brain, E = 3.24 +/- 0.25, eta = 1.10 +/- 0.37 and these moduli were also stable when the physical conditions of the brain were stable. Under the dehydration by 20% mannitol, E increased in its value (p less than 0.01). But under the hydration by 5% glucose, E did not change at all. In the edematous brain, E = 3.28 +/- 0.44, eta = 1.74 +/- 0.06 and E of the edematous brain was almost same as that of normal ones, but under the dehydration, E of the edematous brain decreased (p less than 0.10), on the other hand it increased in its value under the hydration (p less than 0.05). In the necrotic brain, E = 1.60 +/- 0.14, eta = 0.82 +/- 0.28. Both moduli were of lower values and moreover they did not change its values at all under dehydration and hydration. As Young's modulus is the elastic index of the brain, the converse (1/E) should be compliance of the brain, that is to say, buffer effect of the brain. As for the compliance, the necrotic brain has maximum buffer effect and the over-hydrated edematous brain and the dehydrated normal ones have minimum buffer effect. From analysing the changes of the viscous moduli, it became clear that the viscous moduli took quite different functions in alive brains and in fatal ones, and it was suspected that the alive brain might not be so simple in its viscoelastic property.

Urinary retention caused by impaction of enlarged uterus.

2 cases of urinary retention were reported which was caused by retroverted gravid uterus and a large fibroid uterus, respectively. A chain cystourethrography and an endoscopic examination were the most informative to disclose the pathogenesis of urinary retention. Urodynamically, bladder compliance was normal without any pathological contraction. Urethral function was characterized by a shortened functional profile length.

[Experimental studies of skull fracture in the temporal region (author's transl)].

These experimental studies of skull fractures in the temporal region were carried out in co-operation the Faculty of Engineering and the Department of Neurosurgery of Tokyo University. 15 dry human skulls were statically compressed in the bitemporal direction. The results of our experiments are as follows: 1) The forces necessary to produce the first fracture (seperations of the parietotemporal suture) are between 135 kg and 385 kg. (average; 258 kg) 2) The forces necessary to produce the second fractures (true fractures) are between 195 kg and 550 kg. (average; 356.3 kg) 3) The decreases of the inner diameters of skulls from pre-examination to the first fracture are between 0.65 mm and 1.85 mm. 4) The decreases of the inner diameters of skulls from pre-examination to the second fracture are between 1.56 mm and 4.5 mm. 5) The forces necessary to reduce the inner diameters of skulls by 1 milimeter are between 85 kg/mm and 380 kg/mm. (average; 221 kg/mm) The forces necessary to produce a fracture in the temporal region are much less than the forces necessary to do so in the frontal region. In deforming the skull, it is necessary to apply much greater force to the frontal region than it is to the temporal region. The relation between the skull's age and the minimal force to produce the skull fracture is not clear from the results of these experiments. The weights of the skulls were directly related to the minimal force necessary to produce skull fractures. Breaks in the inner table preceded those of the outer table when linear fractures occurred over the compressed area. when depressed fractures formed in the same area, the outer table was broken before the inner table. When the linear fractures formed far from the same area, the outer table was broken before the inner table. From our investigations on sports injuries, those players who died after being hit by golf balls or baseballs showed the same clinical courses as in typical extradural hematoma. Plain X-ray examinations of those fataly injured players did not reveal any skull fractures. Plain X-ray examinations of fractured skulls often failed to reveal the lesion unless the bone fracture was widely separated. On the basis of the above results, it would appear that routine skull films using either anterior-posterior or lateral projections are inadequate for the diagnosis of skull fractures. We have had good results in the examination of skull fracture by using the stereo X-ray method.