Effect of intrauterine repair of diaphragmatic hernia on the accompanying pulmonary hypoplasia in the fetal rabbit

Severe pulmonary hypoplasia precluding the sustenance of life is often found in newborns with prenatally diagnosed congenital diaphragmatic hernia (CDH). In utero repair of the hernia it is thought to be the sole method of salvaging these patients. To study the efficacy and feasibility of in utero repair of CDH, diaphragmatic hernias (DH) were produced successfully in 81 of 90 fetal rabbits by diaphragmatic perforation via a left thoracotomy at 22 days' gestation (term = 31 days). The DHs were repaired successfully in 25 of 50 fetal rabbits at 26 days' gestation. The rabbits with repaired and non-repaired DHs and their litter-mates (the control group) were delivered at 29 days' gestation by cesarean section. Some of the rabbits were killed and subjected to measurements of body and lung weight, determination of the DNA and surfactant (disaturated phosphatidylcholine; DSPC) contents of the lungs, and light and electron microscopic examination of the lung. Some newborn rabbits underwent endotracheal intubation and measurement of pressure-volume curves and pulmonary compliance. The total lung/body weight ratios and total lung DNA contents in the repair group were greater than those in the non-repair Group (P <0.01). There were no differences among the three groups in regard to body weight. When compared with the control group, both the repair and non-repair groups had increased DSPC content (P <0.01 andP <0.05, respectively), although there was no difference between the repair and non-repair groups. Histologically, the thickness of the terminal air spaces was smaller and the size of the lung acini was larger in the repair group than the non-repair group. Electron-microscopically, the number of type 11 lung cells in both the repair and nonrepair groups tended to be larger than that in the control group. When compared with the non-repair group, the repair group showed increased values for pressure-volume curves (P <0.01) and pulmonary compliance (P <0.01). In conclusion, in utero repair of CDHs is effective in improving the hypoplasticity of the lung accompanying this lesion.

Protective effects of antithrombin III supplementation on warm ischemia and reperfusion injury in rat liver

The effect of antithrombin III (AT III) supplementation on energy status, microcirculation, cytoprotection, and prostacyclin (PGI2) production during and after a period of warm ischemia of the rat liver was investigated. AT III supplementation (250 units/kg) stimulate prostaglandin I2 (PGI2) production from 1 hour after administration, with maximal production observed at 3 hours. Ischemia was induced by occluding the hepatoduodenal ligament for 30 minutes, and experiments were continued for 60 minutes after reperfusion. The rats received AT III (250 units/kg IC) 30 minutes before induction of liver ischemia (AT III group). In the AT III group, recovery of the beta-ATP/inorganic phosphate ratio measured by 31P nuclear magnetic resonance showed significant improvement (p < 0.01), and the recovery of tissue blood flow markedly improved (p < 0.01) compared to the saline-treated group (control group). Leakages of aspartame aminotransferase, alanine aminotransferase, and lactate dehydrogenase were mitigated in the AT III group (p < 0. 05). Ultrastructural alterations of sinusoidal endothelial cells were markedly reduced in the AT III group. The PGI2 level at the end of reperfusion was significantly elevated (p < 0.01) in the AT III group compared to the control group. The results of this study indicated that pretreatment with AT III significantly improved the energy status and microcirculation, as well as histologic damage, after liver ischemia and reperfusion. One of the fundamental effects of AT III might be mediated through the production of prostacyclin.

Impact of adhesion molecules of the selectin family on liver microcirculation at reperfusion following cold ischemia

We investigated the role of adhesion molecules in the early phase of reperfusion following cold ischemia. Livers of male Lewis rats were preserved for 0 h (group A) or 24 h in University of Wisconsin (UW) solution without additives (group B) or in UW solution with anti-ICAM-1 antibody (group C) or anti-E-selectin-1, SLe(x) and SLe(a) antibodies (group D). The livers were then reperfused with diluted rat whole blood (DWB; groups A and B). DWB containing anti-ICAM-1 and LFA-1 antibodies (group C) or DWB containing anti-L-selectin, SLe(x) and SLe(a) antibodies (group D). The reperfusion was performed at 37 degrees C for 1 h at 5 cm H2O of perfusion pressure. During reperfusion, hepatic microcirculation was assessed by monitoring portal and peripheral tissue blood flow. Bile production was significantly reduced in group B livers compared with those in group A. Anti-ICAM-1 and LFA-1 antibodies failed to improve hepatic microcirculation, whereas anti-LECAM-1, SLe(x) and SLe(a) antibodies significantly improved the microcirculation. Bile production in group C and D livers was comparable to that in group B livers. Preservation for 24 h significantly increased the release of TNF-alpha from 0.207 to 43.7 pg/g per hour during reperfusion. Monoclonal antibodies to the adhesion molecules did not suppress the release of TNF-alpha in groups C and D. Histological examination demonstrated a lack of leukocyte infiltration or thrombus in hetapic microvessels. The extent of hepatocyte necrosis did not differ among groups B, C, and D. We conclude that the microcirculatory disturbance in the early phase of reperfusion occurs as a result of the tethering of leukocytes through the interaction of the selectin family and their ligands, and that the ICAM-1-LFA-1 pathway is not involved in this step. The lack of improvement in bile production with antibodies to the selectin family and their ligands strongly suggests that other mechanisms participate in the deterioration of hepatic function.

The inflexible mitral annulus after valve prosthesis. Inherent risk of dynamic left ventricular outflow tract obstruction

Although chordal preserving mitral valve replacement is beneficial to cardiac function, the loss of flexibility of the annulus and consequent translational motion of the valve prosthesis during systole may cause potential left ventricular outflow tract (LVOT) obstruction after surgery. The extent of the flexibility of the mitral valve annulus (MVA) necessary for the prosthetic valve to prevent potential LVOT obstruction was determined. The three dimensional images of the MVA at 0, 100, 200, and 300 msec delay from the electrocardiogram R wave were reconstructed from cine-mode magnetic resonance images in eight normal subjects. In the lateral view of the MVA, the dorsal flexion angle (DFA) was defined. This angle implies the extent of the flexion of the anterior half of the MVA in relation to the posterior half. The data (mean +/- SD) for the DFA were 31.7 +/- 5.4 degrees (0 msec), 36.4 +/- 4.5 degrees (100 msec), 39.0 +/- 3.8 degrees (200 msec), and 43.6 +/- 2.6 degrees (300 msec), whereas the systolic increase in DFA was 11.9 +/- 3.2 degrees. The flexibility observed in normal mitral annuli is relevant to prosthetic mitral valves.

Comparison of University of Wisconsin and University of Pittsburgh solutions for heart transplantation

The effectiveness of University of Wisconsin (UW) and University of Pittsburgh (UP) solutions for the preservation of rat hearts was compared. Lewis rat hearts were preserved with UW (group A, n = 45) or UP (group B, n = 45) solution for 0 or 24 h and then transplanted heterotopically into the recipients' abdomen. Ten recipients in each group were observed to obtain 1-week graft survival rates. Tissue water content and tissue content of adenine nucleotides were measured 2 h after transplantation in six grafts from each group. Six hearts preserved for 0 h and seven hearts preserved for 24 h were taken from each group 24 h after grafting for histopathology. The 1-week graft survival rates of groups A24 and B24 were 60% and 10%, respectively. In the 24-h preserved grafts, adenosine triphosphate (ATP) and energy charge [(ATP + adenosine diphosphate/2)/(ATP + adenosine diphosphate + adenosine monophosphate)] of groups A and B were 0.972 +/- 0.165 and 0.200 +/- 0.123 mg/g wet tissue (P < 0.05) and 74.4% and 61.1% (P < 0.05), respectively. The tissue water content of group A24 was 71.7%, whereas that of group B24 was 74.1% (P < 0.05). Histopathology revealed more severe muscle edema and necrosis and infiltration of polymorphonuclear cells in group B24 than in group A24. We conclude that UW solution is more appropriate for rat heart preservation than UP solution.

[A case of new stenosis in the distal portion following transaortic patch angioplasty for the left main coronary stenosis]

A 75-year-old man who had unstable angina underwent transaortic vein patch angioplasty for isolated 60% stenosis of the left main coronary artery. About four months after the operation, he developed effort angina and angiographycally new stenosis was detected in the distal portion of patch dilatation. So he underwent emergency aorto coronary bypass grafting. Transaortic patch angioplasty is attractive technique because of restoration of the original antegrade coronary flow, but this direct surgical approach may induce the stimulation of intima, and may injure the intima. It is important to bear this technique in the mind for selected patients with left main coronary lesions.

Effects of cold preservation and reperfusion on microsomal cytochrome P-450-linked monooxygenase system of the rat liver

The effects of cold preservation and reperfusion of the liver on the hepatic microsomal cytochrome P-450-linked monooxygenase system (P-450 system) were investigated. Rat livers were preserved with cold University of Wisconsin solution for 0, 12, 24, 36, and 48 hr. Half of them in 0-, 24-, and 48-hr groups were reperfused for 1 hr at 37 degrees C with oxygenated Krebs-Henseleit buffer. After preservation or reperfusion, the liver microsomes were prepared and the concentration of each component of the P-450 system [NADPH-cytochrome b5 reductase (b5 reductase), cytochrome b5 (b5), NADPH-cytochrome P-450 reductase (P-450 reductase) and cytochrome P-450 (P-450)] and their drug metabolizing activities and concentration of apo-cytochrome P-450 2E1 (apo-P-450 2E1) were measured. After 48-hr preservation, b5 concentration did not decrease, whereas the concentration of P-450, P-450 reductase, and b5 reductase decreased from 0.865 to 0.676 nmole/mg protein, from 0.262 to 0.233 micromole/mg protein/min and from 5.34 to 4.86 micromole/mg protein/min, respectively. During cold preservation, the activities of p-nitroanisole O-demethylase and aniline p-hydroxylase did not change. Aminopyrine N-demethylase activity was inhibited from 4.45 to 3.34 nmole/mg protein/min after 48-hr cold preservation. Apo-P-450 2E1 was gradually decreased during cold preservation. Reperfusion caused a further decrease in the activities and concentration of the components of the P-450 system and concentration of apo-P-450 2E1 to 80-90% after 1-hr reperfusion. It was suggested that the prolonged preservation caused deterioration of the P-450 system and the loss of the abilities of metabolism and detoxication of xenobiotics.

Intravenously-injected naloxone reverses the decrease in renal sympathetic nerve activity seen during hypotensive hemorrhage in conscious rabbits by acting through central mechanisms

The response of renal sympathetic nerve activity (RNA) to hemorrhage was examined in chronically-instrumented conscious rabbits. Hemorrhage was induced at a rate of 5 ml/kg per min until the mean arterial pressure fell below 40 mmHg. The mean arterial pressure then remained at around 80 mmHg until 10 ml/kg of hemorrhage (normotensive hemorrhage) before falling to below the pre-hemorrhagic control level (hypotensive hemorrhage). The RNA response showed a biphasic pattern, i.e., it increased during normotensive hemorrhage, then fell below the control level during hypotensive hemorrhage. To examine the mechanism involved in this decrease in RNA, naloxone (7.5 mumol/kg), an opioidergic receptor antagonist, was intravenously injected 1 min after the end of hemorrhage. Intravenous injection of naloxone caused an increase in mean arterial pressure and RNA to the level seen during normotensive hemorrhage. These results indicate that the decrease in RNA induced by hypotensive hemorrhage is mediated by opioidergic receptors. To determine whether the effects of naloxone are mediated via central or peripheral opioidergic receptors, naloxone was replaced by an equimolar solution of methylnaloxone, a form unable to cross the blood-brain barrier. Neither the mean arterial pressure nor RNA was significantly altered by administration of methyl naloxone. These results suggest that the effects of naloxone on both the RNA and the mean arterial pressure are mediated via central opioidergic receptors, i.e., the sympathoinhibition induced by hypotensive hemorrhage is mediated via the stimulation of central opioidergic receptors.

A Method for Purification of Clostridium perfringens Phospholipase C from Recombinant Bacillus subtilis Cells

We developed a method to purify Clostridium perfringens phospholipase C from a culture of recombinant Bacillus subtilis cells. This method consists of three purification steps, and it allowed us to obtain 6.2 mg of pure phospholipase C from 800 ml of culture.

Simultaneous occurrence of medullary carcinoma and papillary carcinoma of the thyroid

We report a case of simultaneous occurrence of medullary carcinoma and papillary carcinoma of the thyroid in the same thyroid gland. Immunoreactivity of calcitonin, carcinoembryonic antigen, neuron specific enolase and thyroglobulin made a sharp distinction between both neoplasms of the thyroid. It appears reasonable to consider that simultaneous occurrence of medullary carcinoma and papillary carcinoma of the thyroid in this case does not have embryological or genetical significance.

[A percutaneously controllable pulmonary artery banding device: clinical application]

An optimal pulmonary artery banding is often difficult with a conventional banding technique. It often requires readjustment after closing the chest. So we developed a percutaneously controllable pulmonary artery banding device and applied it in three patients. This device consists of silicone balloon being pasted on a reinforced silastic plate and silicone reservoir. The balloon is applied around the pulmonary artery and the reservoir is implanted subcutaneously. The control of the banding is accomplished percutaneously through the reservoir using a needle with fluid-filled syringe. This device worked successfully in two patients for percutaneous readjustment of pulmonary constriction and congestive heart failure was decreased. This device may offer proper constriction of the pulmonary artery without any surgical procedures after banding and may reduce surgical morbidity and mortality of sick children.

Autologous pericardial patch repair for postinfarction ventricular septal perforation

Surgical therapy for ventricular septal perforation associated with acute myocardial infarction is thought to reduce ventricular chamber volume and distort the ventricle due to excision of the myocardium. A 69-year old man underwent elective surgery that used an autologous pericardial patch without excising the myocardium. Intraventricular repair using the autologous pericardial patch enabled preservation of ventricular geometry and chamber volume and did not result in a depression of cardiac function. Moreover, it has been reported that this surgical procedure protects against suture bleeding and decreases the amount of foreign material required, thus possibly reducing the risk of infectious complications.

Effects of left intraatrial infusion of prostaglandin E1 after open-heart surgery

The hemodynamic effects of a left intraatrial infusion of prostaglandin E1 (PGE1) given to ten patients after open-heart surgery (LA group), were compared with those following no treatment in a control group of ten patients, and to those following a right intraatrial infusion given to another ten patients (RA group). PGE1 was infused at a rate of 0.03 microgram/kg/min in the RA group and at 0.003 microgram/kg/min in the LA group, and hemodynamics were measured immediately after surgery, then 3, 6, and 12 h after the PGE1 infusion was commenced. The heart rate, right atrial pressure, left atrial pressure, and mean pulmonary arterial pressure remained almost unchanged in all three groups; however, the mean radial arterial pressure and systemic vascular resistance index decreased, and the cardiac index increased in the RA and LA groups. The pulmonary vascular resistance index decreased only in the LA group. Thus, a much smaller dose of PGE1, being one-tenth of that used for the right atrial infusion, administered directly into the left atrium yielded almost the same hemodynamic effects as the larger dose infused into the right atrium. Furthermore, this method of infusing PGE1 is safe, efficacious, and cost-efficient.

Study of cardiac structures in relation to the pericardial cavity for total artificial heart implantation

To enhance the design of the completely implantable total artificial heart (TAH), we developed a coordinate system that expresses the geometry of the heart, including that at the interface with the TAH and that of the pericardial cavity. This coordinate system (ventricular coordinate system) was developed using 3D images of the heart which were obtained from magnetic resonance images. The origin is located on the centroid of the mitral annulus at 25 ms delay from the ECG R wave (M0), and the y axis is the axis from M0 to the apex at 25 ms delay (Apex0). The x-y plane includes M0, Apex0, and the centroid of the tricuspid annulus at 25 ms delay. Since the y axis expresses the apical orientation of the heart, data using this coordinate system are not affected by individual variation in heart orientation. Heart geometry data were obtained in 5 normal subjects. Compared with that using the coordinate system based on the thoracic wall, the expression of the data of interface geometry for the heart and the TAH is simplified when the ventricular coordinate system is used. A method of expressing the geometry of the pericardial cavity using the ventricular coordinate system is also proposed. These methods may be applicable in obtaining data in patients suffering from cardiomyopathy.

Role of endogenous opioids and central opioid receptors in cerebral cortical blood flow autoregulation

To examine the role of endogenous opioids in autoregulatory maintenance of cerebral cortical blood flow (CoBF), CoBF was measured continuously by laser-Doppler flowmetry during changes in arterial pressure. Experiments were conducted on pentobarbital sodium-anesthetized adult mongrel dogs. Mean arterial pressure (MAP) was decreased or increased by inflating a perivascular occluder placed around the inferior vena cava or the thoracic descending aorta, respectively. To exclude the influence of the baroreceptor reflex on the autoregulatory maintenance of CoBF, all experiments were conducted on dogs with bilateral carotid sinus denervation plus vagotomy. CoBF was well maintained within its normal range despite large changes in MAP. Intravenous injection of naloxone (2.5 mumol/kg), an opioid receptor antagonist, significantly impaired the autoregulatory maintenance of CoBF during the decrease in MAP. On the other hand, intravenous injection of methyl naloxone (2.5 mumol/kg), which does not cross the blood-brain barrier, did not exert any significant effect on the MAP-CoBF relationship. Furthermore, intracerebroventricular injection of a smaller dose of naloxone (2.5 nmol/kg) significantly impaired the autoregulatory maintenance of CoBF during the decrease in MAP, as the larger dose of intravenous naloxone (2.5 mumol/kg) did. On the other hand, intravenous injection of the smaller dose of naloxone did not exert any significant effect on the MAP-CoBF relationship. These findings suggest that endogenous opioids and central opioid receptors may be partly involved in the CoBF autoregulatory mechanism. The endogenous opioids may modulate the autoregulatory vasodilation of the cerebral cortex during the decrease in MAP.

Development of a fistula between an internal mammary artery graft and the pulmonary vasculature following coronary artery bypass grafting: report of a case

We report herein the rare case of a 56-year-old man who gradually developed congestive cardiac failure 6 months after undergoing coronary artery bypass grafting and was found to have a fistula between the internal mammary artery and the pulmonary artery of the upper lobe diagnosed by selective left internal mammary arteriogram. A second sternotomy was performed and demonstrated dense adhesion between the fissure surrounding the internal mammary artery and the upper lobe, and the fistula was resected. We believe that the patient's increasing cardiac failure was almost certainly caused by coronary seal.

Prediction of the early prognosis of the hepatectomized patient with hepatocellular carcinoma with a neural network

The early prognosis of the hepatectomized patients with hepatocellular carcinoma was determined preoperatively with a perceptron-type neural network. The neural network was trained with the preoperative data of 54 example cases with the early prognosis, successful or died of hepatic dysfunction, as teaching signals. After learning these examples, the neural network came to give a precise prediction to the example data except for one case. With the learned neural network, the outcomes of the hepatectomy of 11 patients (10 successful; 1 died) were predicted prospectively with 100% precision. The usefulness of the neural network for the prediction was determined.

Mitral annular function assessed by 3D imaging for mitral valve surgery

We developed a surgical technique for mitral valve reconstruction without a prosthetic ring. This procedure may have two advantages. One is avoidance of the potential thrombogenicity of the prosthetic ring, and the other is that this procedure may maintain the normal function of mitral annulus. To clarify the latter advantage, we defined a method for 3D assessment of the heart, especially for the dynamic changes of the mitral annulus. 3D images of the heart, including both mitral and tricuspid annuli in eight phases during the cardiac cycle, were reconstructed from magnetic resonance images of seven normal subjects, and used for this study. To depict the changes in the annular shape, we determined the following parameters of the annular function: (a) annular excursion, (b) direction of motion (direction cosine) and (c) orientation of the annulus (direction cosine) for the annular motion, (d) annular area and (e) displacement of the anterior portion from the approximated plane of the annulus. The data for the systolic annular motion indicate that the mitral annulus moves towards the apex with slight caudal deviation, with the excursion of 12.1 mm. The change in annular orientation indicates that the mitral annulus shows translational motion during systole. The mitral area was reduced by 25.6% (n = 5) from mid-diastole to mid-or late systole. Displacement at the anterior portion of the annulus did not change markedly during systole. The results demonstrate the physiologic function of the mitral annulus in normal subjects. This method will be applied to the clinical study of mitral valve reconstruction surgery. Based on the differences in annular length in intact and excised states, we describe the intact state of the posterior leaflet as "natural redundancy." Restoration of this natural redundancy has been a hallmark of successful mitral repair for over 20 years.

Chordal reconstruction with polytetrafluoroethylene (PTFE) sutures for mitral regurgitation

Chordal reconstruction of the mitral valve using CV4 or CV5 polytetrafluoroethylene (PTFE) (Gore-Tex. Flagstaff, AZ, USA) sutures was performed in seven patients with mitral regurgitation (MR) to ascertain its efficacy. The MR had been caused by prolapse of the anterior leaflet in three patients, the posterior leaflet in two, and both leaflets in two; five of the patients had an MR of grade III or IV. There was one hospital death, which occurred in a patient whose MR had resulted from papillary muscle dysfunction caused by a myocardial infarction (MI). Chordal reconstruction failed and was converted to a mitral valve replacement in two patients, one of whom had suffered a MI and another who had a congenital papillary muscle anomaly. The remaining five patients all underwent successful chordal reconstruction with PTFE sutures, resulting in the disappearance of the MR in two patients and an improvement to grade I in three patients. Although the longest follow-up period has been only 1 year, the MR has not worsened. This technique is relatively easy to perform, and allows almost all the mitral apparatus to remain in situ, while enabling repair of the mitral valve, regardless of the state of the diseased chordae.