Colon stenosis caused by old portal vein thrombosis.

A 58-year-old female with a history of portal vein thrombosis was referred to our hospital with abdominal pain and distention. Colon fiber and enema of the colon showed stenosis at the transverse colon and the ascending colon, with edematous mucosa. Laparotomy revealed no abnormal findings other than chronic ischemia of the colon. To our knowledge, this is the first reported case of colon stenosis caused by portal vein thrombosis.

Large cholesterol polyp of the gallbladder mimicking gallbladder carcinoma.

Gallbladder tumors larger than 10 mm in diameter have a high incidence of malignancy. We report an extremely rare case of a large cholesterol polyp of the gallbladder mimicking gallbladder carcinoma. Ultrasonography and computed tomography showed a larger papillary mass in the fundus of the gallbladder with a maximum diameter of about 30 mm, the largest gallbladder polyp ever reported to our knowledge.

Intussusception caused by primary malignant melanoma of the small intestine.

Whether melanoma develops as a primary tumor in the small bowel remains controversial. A 57-year-old male Japanese presented signs of intestinal obstruction. Ultrasonography and computed tomography disclosed an abdominal mass with multiple concentric rings, characteristic of intussusception. At surgery, a spherical tumor, 3.8 cm in diameter, with scattered pigmentation was found to lead the intussusception. Segmental intestinal resection with regional lymph node dissection was performed. Pathological examination revealed diffuse infiltration of malignant melanoma cells. Nodal metastasis was seen only in the mesenteric node draining from the tumor-bearing intestinal segment. Twelve months after surgery, melanoma recurred in the liver and para-aortic lymph nodes, where a malignancy of the digestive organs frequently metastasizes; however, no extraperitoneal melanoma was found after repeated examinations. Thus, this case suggests that primary malignant melanoma can originate in the small intestine and be a cause of intussusception in the adults.

Surgical excision of adrenal masses; a ten-year experience.

We reviewed the records of 13 patients with adrenal masses operated on over a ten-year period to clarify clinical characteristics of adrenal tumors. Tumors were found incidentally in seven of nine patients with primary adrenal tumors (78%); however, three of these seven patients (43%) proved to have shown symptoms related to adrenal hyperfunction when re-evaluated. Other adrenal tumors (metastatic in three patients and inflammatory in one) were found without any symptoms referable to the tumors. In nine of 13 patients (69%), tumors were discovered by computerized tomography (CT). All patients with primary tumors have been gotten free of disease postoperatively. In contrast, although all three patients with metastatic adrenal tumors underwent resection of all known disease tissue, they died of the recurrence of malignancies within 10 months. This study suggests that a number of functional adrenal tumors are possibly left undiagnosed until found incidentally, and that CT is the most powerful tool to detect adrenal tumors. Our data did not support surgical intervention in cases of metastatic adrenal tumors.

Evaluation of microcirculation in the tumor-bearing liver of rabbits by laser-Doppler flowmetry.

Hemodynamic changes in normal liver tissue and in intrahepatic tumors (Vx2 carcinoma) after occlusion of the hepatic arterial branch or the portal branch (ex. 1), and with intrahepatic arterial infusion of vasoactive agents (ex. 2) were studied in rabbits by a laser-Doppler flowmeter. Ex. 1: After occlusion of the hepatic arterial branch to the main lobe, laser-Doppler flow (LDF) in main lobe normal tissue decreased by 11 +/- 11% in the control group, 37 +/- 37% in group Ia (tumors were 10-20 mm in diameter) and 49 +/- 37% in group Ib (tumors were 25-50 mm), so it seemed that the proportion of portal blood flow in the normal tissue microcirculation decreased with tumor growth. The tumor LDF decreased by 88 +/- 13%. After occlusion of the portal branch, the normal tissue LDF in the main lobe decreased and then recovered slightly (most evident in the control group and least in group Ib). This recovery was probably due to the hepatic arterial buffer response. The tumor LDF decreased by 36 +/- 10% in group Ia and 11 +/- 17% in group Ib. There was no difference between group I (tumors were implanted directly) and group II (tumors were implanted via portal vein). Ex. 2: Adenosine and prostaglandin E1 increased blood flow in the normal tissue and decreased the tumor blood flow, while angiotensin II had the opposite effect. Vasoactive agents can be used to selectively increase or decrease tumor blood flow and are available as adjuvants for the treatment of liver tumors. Adenosine may enhance the selective tumor heating in local hyperthermia.

A cAMP-dependent protein kinase inhibitor modulates the blocking action of ATP and 5-hydroxydecanoate on the ATP-sensitive K+ channel.

We studied the blocking mechanism of 5-hydroxydecanoate, a novel antiarrhythmic agent, on the ATP-sensitive K+ channel in the single ventricular myocytes using the inside-out patch clamp technique. The channel activity in response to 5-hydroxydecanoate varied with each membrane patch corresponding to the sensitivity to ATP. In this condition the exogenous application of cAMP or cAMP-dependent protein kinase (PKA) obviously recovered the ATP-sensitive K+ channel activity after channel deactivation. By contrast, in membrane patches exhibited low sensitivity to ATP, endogenous cAMP-dependent protein kinase inhibitor (PKI) depressed the channel activity and restored the inhibitory action of 5-hydroxydecanoate and ATP on the channel. These results suggest that PKA-PKI system is involved in the regulatory mechanism of gating activity of the ATP-sensitive K+ channel and the blocking action of 5-hydroxydecanoate and ATP appears to be exerted by potentiating the inhibitory action of PKI on the channel.

Usefulness of preoperative low dose cisplatin treatment for advanced esophageal cancer.

In order to decrease the perioperative complications by preoperative cisplatin chemotherapy, the preoperative single administration of cisplatin (30 mg/m2) was performed weekly from one to six times in 36 consecutive patients with esophageal cancer classified as higher than Stage II. The survival curve of 17 patients in Stage III was significantly better (P < 0.05) than that of patients who had been treated without preoperative cisplatin treatment. In 3 of the 12 patients who had locally invasive cancer, either the main tumors or the metastatic lymph nodes, which had invaded the trachea or the left main bronchus, sufficiently receded, so that a curative esophagectomy became possible; 2 of them have survived over 33 months while 1 died of pneumonia 33 months after surgery. The number of perioperative complications was minimal, and thus, we consider that the postoperative use of cisplatin and fluorouracil is indicated in patients in whom a histological response is noted in the resected specimens.

Protein rotation study of cytochrome P-450 in submitochondrial particles: effect of KCl and intermolecular interactions with redox partners.

The rotational diffusion of cytochrome P-450 in submitochondrial particles (SMP) of bovine adrenocortical mitochondria was measured by detecting the decay of absorption anisotropy, r(t), after photolysis of the heme.CO complex by a vertically polarized laser flash. Analysis of r(t) was based on a "rotation-about-membrane normal" model. The measurements were used to investigate the effect of KCl on intermolecular interactions involving cytochrome P-450 and to investigate the interactions of cytochrome P-450 with other redox partners. The rotational diffusion of cytochrome P-450 was significantly dependent on KCl concentration. When the KCl concentration was increased from 0 to 1,000 mM, the mobile population of cytochrome P-450 was increased from 33 to 82%. After removing the KCl, the mobile population of cytochrome P-450 returned to the original 33%. These results suggest that nonspecific protein aggregates are dissociated by the presence of KCl, possibly due to the change in electrostatic interactions, resulting in mobilization of cytochrome P-450. SMP were observed to be nearly free from adrenodoxin and adrenodoxin reductase. The addition of adrenodoxin to SMP increased the mobile population of cytochrome P-450 from 35 to 54%. Further addition of adrenodoxin reductase to SMP containing adrenodoxin immobilized cytochrome P-450 by 6%. The addition of only adrenodoxin reductase to SMP, however, did not immobilize cytochrome P-450. The present results are consistent with our previous observations [Ohta, Y., Mitani, F., Ishimura, Y., Yanagibashi, K., Kawamura, M., & Kawato, S. (1990) J. Biochem. 107, 97-104] that cholesterol-bearing P-450SCC forms a transient ternary association with adrenodoxin and adrenodoxin reductase.

Synthesis of aldosterone by mitochondria and homogeneous 11 beta-hydroxylase from beef and pig.

It was found that homogeneous 11 beta-hydroxylase from bovine and porcine adrenals catalyzes the conversion of DOC to aldosterone. Mitochondria from both glomerulosa and fasciculata also convert DOC to aldosterone but glomerulosa is much more active than fasciculata. Cholate extracts of mitochondria from the two zones were equally active in converting DOC to aldosterone. Moreover all the enzyme activities of 11 beta-hydroxylase (including 18-hydroxylation and aldehyde synthetase) were precipitated by a polyclonal antibody raised in rabbit against the pure 11 beta-hydroxylase. It is concluded that in beef and pig a single adrenocortical 11 beta-hydroxylase is responsible for the synthesis of aldosterone. To determine the influence of the mitochondrial membrane from glomerulosa and fasciculata on the activities of 11 beta-hydroxylase we examined the activities of rotenone-insensitive reductase enzymes in mitochondria from the two zones. Semidehydroxyascorbate reductase and NADH-cytochrome C reductase activities are considerably more active in glomerulosa than in fasciculata mitochondria. Moreover ascorbate plus NADH (but not ascorbate alone) greatly increases the ability of malate and NADPH to support synthesis of aldosterone without affecting 11 beta- or 18-hydroxylations in mitochondria. It is proposed that maximal synthesis of aldosterone by adrenocortical mitochondria requires in addition to the usual electron transport system (NADPH- greater than ADR- greater than ADX- 11 beta-OHase) an auxilliary system in the outer mitochondrial membrane: NADH- greater than Fp- greater than cyt b- greater than semidehydroascorbate reductase.

Ascorbate as a source of reducing equivalents for the synthesis of aldosterone.

The three steps in the synthesis of aldosterone (11 beta/18-hydroxylations and aldehyde synthetase) were examined in mitochondria from bovine glomerulosa and fasciculata to study the regulation of aldehyde synthetase. Ascorbate plus NADH shows synergism with malate in stimulating aldehyde synthetase without affecting 11 beta/-18-hydroxylations. The concentration of semidehydroascorbate reductase in mitochondria from glomerulosa is more than twice that from fasciculata. We propose that in glomerulosa, ascorbate provides a source of reducing equivalents that specifically support the last step in the synthesis of aldosterone.

Voltage-dependent Ca2+ channels are involved in regulation of steroid synthesis by bovine but not rat fasciculata cells.

Bovine but not rat fasciculata cells show a concentration-dependent stimulation of the production of corticosteroids by addition of external Ca2+ to the incubation medium. Both cell types respond to ACTH in a concentration-dependent manner. Increasing concentrations of K+ (0-20 mM) cause increased production of corticosteroids and accelerated influx of Ca2+ in bovine fasciculata cells but no change in either of these two parameters in rat fasciculata cells. Two inhibitors of Ca2+ channels (nifedipine and PY108-068) inhibit both the production of steroids by unstimulated bovine cells and the stimulation produced by three agents (ACTH, (Bu)2 cAMP, and K+). Half-maximal inhibition of these responses was produced in each case by submicromolar or low micromolar concentrations of the inhibitors. These inhibitors are without effect in rat fasciculata cells. One Ca2(+)-channel agonist (BAY K8644) stimulated synthesis of steroids by bovine cells and potentiated the response to ACTH. The agonist acts in the low micromolar range but was without effect on rat cells or on the responses of steroid synthesis by these cells to either ACTH or dibutyryl cAMP. Moreover, bovine fasciculata cells show specific binding sites for [+]PN 200-110, a specific ligand for 1,4-dihydropyridine receptors associated with voltage-dependent Ca2+ channels [dissociation constant (Kd), 14.3 nM; maximum number of binding sites (Bmax), 0.52 pmol/10(6) cells]. Rat cells show no specific binding of PN 200-110. We conclude that bovine fasciculata cells possess voltage-dependent Ca2+ channels which are involved in the regulation of steroid synthesis in these cells and that rat fasciculata cells are without such channels.

Conversion of cholesterol to pregnenolone mobilizes cytochrome P-450 in the inner membrane of adrenocortical mitochondria: protein rotation study.

Rotation of cytochrome P-450 was examined in bovine adrenocortical mitochondria before and after an enzymatic transformation of cholesterol into pregnenolone by cytochrome P-450scc in the presence of malate. Rotational diffusion was measured by observing the decay of absorption anisotropy, r(t), after photolysis of the heme.CO complex by a vertically polarized laser flash. Analysis of r(t) was based on a "rotation-about-membrane normal" model. The measurements were used to investigate substrate-dependent intermolecular interactions of cytochrome P-450 with other redox components. Rotational mobility of cytochrome P-450 was significantly dependent on the decrease in cholesterol content by side chain cleavage reaction catalyzed by cytochrome P-450scc. In a typical experiment, the observed value for the normalized time-independent anisotropy r(infinity)/r(0) was decreased from 0.78 in control mitochondria to 0.60 after conversion of 21% of cholesterol to pregnenolone, while no significant change was observed for the average rotational relaxation time phi of about 700 microseconds. Significantly high values of r(infinity)/r(0) = 0.78 and 0.60 imply co-existence of mobile and immobile populations of cytochrome P-450. Since we observed that the heme angle tilted 55 degrees from membrane plane, 22% (control mitochondria) and 40% (after conversion of cholesterol to pregnenolone) of cytochrome P-450 in mitochondria are calculated to be mobile in the preparation. The significant mobilization of cytochrome P-450scc molecules caused by the conversion of cholesterol to pregnenolone is likely due to changes in protein-protein interactions with its redox partners, since the lipid fluidity was kept unchanged by the cholesterol depletion.(ABSTRACT TRUNCATED AT 250 WORDS)

Peripheral-type benzodiazepine receptors are involved in the regulation of cholesterol side chain cleavage in adrenocortical mitochondria.

In an attempt to elucidate the physiological relevance of the peripheral type of benzodiazepine receptor in adrenocortical mitochondria, we examined the effect of three different benzodiazepines (diazepam, Ro5-4864, and chlordiazepoxide) on the conversion of cholesterol to pregnenolone, the rate-limiting step in steroidogenesis, by using cholesterol-loaded mitochondria from bovine adrenal zona fasciculata. These benzodiazepines, except chlordiazepoxide, caused a dose-dependent stimulation of the cholesterol side chain cleavage in the mitochondria. The stimulatory effect of Ro5-4864 was approximately 10 times more potent than that of diazepam. No inhibitory effect of YM-684 (Ro15-1788), a potent antagonist to central-type benzodiazepine receptors, was observed in the stimulation induced by diazepam and Ro5-4864. Both external calcium ion and voltage-dependent calcium channel blocker, (+)-PN200-110, were without effect on the diazepam-induced steroidogenesis. By contrast, pretreatment of mitochondria with digitonin abolished the stimulatory effect of diazepam on the mitochondrial steroidogenesis. The present results indicate that the peripheral-type benzodiazepine receptor of adrenocortical mitochondria plays an essential role in regulating cholesterol side chain cleavage without any change of calcium channels.

Diazepam potentiates the corticoidogenic response of bovine adrenal fasciculata cells to dibutyryl cyclic AMP.

To provide a possible role of peripheral type benzodiazepine receptors in the regulation of glucocorticoid biosynthesis. We have examined the effect of diazepam on the corticoidogenic response to dibutyryl cyclic AMP in isolated bovine adrenal fasciculata cells. Diazepam alone (up to 100 microM) had no effect on the corticoidogenesis. Diazepam caused a dose-dependent potentiation of dibutyryl cyclic AMP-induced corticoidogenesis. However, diazepam had no effect on the corticoidogenic response to ACTH and a high concentration of KCl. The potentiating effect by diazepam was clearly detected after 90 min-incubation, and it was blocked by YM-684 (diazepam antagonist) and ML-236B (cholesterol de novo synthesis inhibitor). Diazepam caused no significant decrease of intracellular content of cholesteryl esters during the corticoidogenic response to dibutyryl cyclic AMP. When the cells were incubated in the presence of (+)-PN200-110, a potent voltage-dependent Ca channel inhibitor, the potentiating effect by diazepam was not affected in spite of a significant inhibition of dibutyryl cyclic AMP-induced corticoidogenesis. These results indicate that the potentiating effect of diazepam on dibutyryl cyclic AMP-induced corticoidogenesis is due in part to the activation of the intracellular cholesterol supply system (cholesterol de novo synthesis) without any change of voltage-dependent Ca channels.

Identification of des-(Gly-Ile)-endozepine as an effector of corticotropin-dependent adrenal steroidogenesis: stimulation of cholesterol delivery is mediated by the peripheral benzodiazepine receptor.

Delivery of cholesterol to inner mitochondrial membranes is rate-limiting for steroidogenesis in the zona fasciculata of adrenal cortex. A protein that stimulates this process was isolated to homogeneity from bovine adrenal tissue. This protein's primary structure has been determined in its entirety by a combination of automated Edman microsequencing, fast-atom bombardment mass spectrometry (FAB-MS). The sequence was identical to that previously reported for bovine brain endozepine, except that it lacks the last two residues, -Gly-Ile, at the C terminus. To our knowledge, isolation of an endozepine-related protein from a tissue other than brain has not been reported previously. Endozepine competes with benzodiazepines for saturable binding sites in synaptosomes and in mitochondria of specific peripheral tissues. Previous reports have localized the adrenal benzodiazepine receptor to the outer mitochondrial membrane. In this report, we show that the prototypic benzodiazepine, diazepam, effects a stimulation of adrenal mitochondrial cholesterol delivery similar to that observed for endozepine. The effective diazepam concentration was consistent with that previously shown to displace a high-affinity ligand of the mitochondrial benzodiazepine receptor. The action of diazepam in adrenal mitochondria suggests that the mediation of corticotropin-induced steroidogenesis may be the physiological function of the peripheral-type benzodiazepine receptor. These studies provide new insights into the previously unknown function of peripheral benzodiazepine receptors and should allow new investigations into the stimulation of steroidogenesis by endozepines and benzodiazepines in the brain and in certain peripheral tissues.

Forskolin activates voltage-dependent Ca2+ channels in bovine but not in rat fasciculata cells.

The action of forskolin on bovine and rat fasciculata cells was examined in freshly prepared cells. Bovine cells show a close parallelism between production of steroids and production of cAMP as a function of the concentration of ACTH up to 10(-8) M. By contrast, forskolin (10(-7)-10(-5) M) causes a similar increase in steroid synthesis but relatively little effect on the production of cAMP. cAMP-dependent protein kinase shows a similar response to ACTH but no response to forskolin in the same range of concentrations. ACTH and forskolin, at submaximal concentrations, cause greater steroid production when added together than when added separately, but the two agents at high concentrations produce the same response whether added together or separately. The inhibitors of voltage-dependent Ca2+ channels inhibit the steroidogenic response to forskolin (IC50 for nifedipine is 0.1 microM and for Py108-068 is 0.4 microM). A Ca2+ channel agonist (BAY K8644) increases the steroidogenic response of bovine adrenal cells to forskolin, but not that of ACTH. Finally, forskolin causes a concentration-dependent uptake of Ca2+ by these cells; in the concentration range of 0.1-10 microM, forskolin caused an increase in [Ca2+] from 185 nM to 345 nM. By contrast, forskolin caused some stimulation of the production of cAMP, but not that of steroids in rat fasciculata cells. It is concluded that in bovine fasciculata cells forskolin activates voltage-dependent Ca2+ channels with a consequent increase in steroid synthesis. This effect is independent of the well known action of forskolin on adenylate cyclase. Rat fasciculata cells, on the other hand, do not possess such Ca2+ channels and do not show a steroidogenic response to forskolin.

Postoperative radiation therapy for esophageal cancer.

The value of postoperative radiation therapy (RT) was investigated in 77 patients with esophageal cancer resected between 1977 and 1986. Surgical resection was palliative in 13 of these patients. Although seven of them underwent postoperative irradiation to the residual tumor, all of the patients died within one year. Following potentially curative resection performed in 64 patients, 31 patients received 50 Gy of postoperative RT to the lower neck and the mediastinum (group Ia), seven were unable to receive full-dose postoperative RT (group Ib), and 26 were not treated with postoperative RT (group II). The 5-year survival rate estimated by the Kaplan-Meier method was 54% for group Ia, 29% for group Ib, and 33% for group II, with the difference between groups Ia and II being significant (p less than 0.025). The local recurrence rate in the mediastinum was lower in group Ia than in group II. Prophylactic postoperative RT for esophageal cancer is a safe and effective regimen for patients with resected disease.

Transthoracic resection of esophageal cancer in patients with pulmonary dysfunction. Usefulness of high frequency ventilation during thoracotomy.

Although curative resection of esophageal cancer has become a safe procedure, in patients with pulmonary dysfunction, postoperative complications remain a serious problem. Of 122 patients who had transthoracic resection of esophageal cancer, 27 had pulmonary dysfunction; in six, the forced vital capacity was less than 70% (minimum of 42.8%, mean +/- SD of 56.6 +/- 8.9%); in 18, forced expiratory volume for one second (FEV1%) was less than 70% (minimum of 34.6%, mean +/- SD of 60 +/- 10%); and in three, both forced vital capacity and forced expiratory volume was less than 70%. Two patients had undergone hemipneumonectomy before receiving resection of the esophagus. During the intrathoracic operative procedure, high frequency ventilation was used, providing good surgical exposure and contributing to a decrease of postoperative pulmonary complications. There were no deaths during the month after surgery. The survival curve of these patients was not significantly different from that of other patients who had had esophagectomy for cancer of the esophagus. These patients survived for an average of 24 months. The patient who survived the longest has been alive for more than 11 years.