Changes in biliary glutathione level during ischemia-reperfusion of rat liver

Changes in hepatic and biliary glutathione levels were studied in rat liver treated with tert-butyl hydroperoxide (t-BuOOH) and subjected to ischemia-reperfusion. Immediately after t-BuOOH administration, the oxidized glutathione (GSSG) values and reduced glutathione (GSSG/GSH) ratio in the bile increased dose-dependently and then returned to control level within 10 min, whereas the hepatic ATP level and bile flow rate were not affected by t-BuOOH at doses of up to 1.0 mmol/kg. These data suggested that the liver remains viable on treatment with up to 1.0 mmole/kg t-BuOOH, and that hepatocytes can rapidly dismute t-BuOOH at up to this dose. The hepatic GSH and GSSG levels did not vary appreciably during ischemia for 10 or 30 min or during subsequent reperfusion, but the GSSG/GSH ratio increased after ischemia for 30 min. The rate of bile flow and the biliary level of GSH decreased after ischemia for 30 min in proportion to the decrease in the hepatic ATP level. However, the biliary GSSG concentration did not vary on reperfusion, although GSSG secretion into the bile is also related to the hepatic ATP level. As a result, the GSSG/GSH ratio in the bile increased during reperfusion after ischemia for 30 min. This increased ratio is thought to reflect oxidation of hepatic GSH by hydroperoxide produced during reperfusion. The GSSG/GSH ratio in the bile after 30 min ischemia corresponded to that observed after a small dose (0.07 mmole/kg body wt) of t-BuOOH, which hepatocytes could dismute rapidly without loss of their viability.(ABSTRACT TRUNCATED AT 250 WORDS)

Gene expression of tumor necrosis factor alpha and interferon gamma in the lungs of Mycoplasma pulmonis-infected mice

ICR mice were infected intranasally with Mycoplasma pulmonis isolated freshly from the lungs of a rat with pneumonia. We demonstrated with high reproducibility the expressions of messenger RNAs of cytokines, tumor necrosis factor alpha (TNF alpha) and interferon gamma (IFN gamma) in the lung tissue of M. pulmonis-infected mice by the reverse transcriptase-polymerase chain reaction and confirmed specific mRNA of the cytokines by restriction endonuclease digestion. Both the viable population of M. pulmonis in the lung tissue and the titers of the neutralizing antibody in the serum increased between 7 and 21 days, and reached their maximum 35 days after infection. The pneumonia in mice progresses with the development of lung lesions after 7 days of infection. The early lesions are characterized primarily by neutrophils and edema in the alveolar spaces. mRNAs prepared from the lung tissue of M. pulmonis-infected and -uninfected mice were also tested for the presence of messages specific to TNF alpha and IFN gamma by the reverse transcriptase-polymerase chain reaction. The expression of the genes encoding TNF alpha and IFN gamma was constitutively demonstrated from 24 hr through 35 days after the intranasal inoculation of M. pulmonis. Furthermore, cells of two types, adherent and nonadherent cells, in bronchoalveolar lavage fluids obtained from the mice 3 weeks after inoculation of M. pulmonis were also found to express the genes of TNF alpha and IFN gamma respectively. These data suggest that these cytokines would play a role in both stimulation in the development of pathological changes in mycoplasmal infection, affecting the inflammatory responses.

[Primary mediastinal tumors in children--comparison with mediastinal tumors in adults]

During the past 43 years, 628 patients with a primary mediastinal tumor underwent surgical operation in our institution. Of those patients, 106 patients (16.9%) were children of 15 yr of age or less and 522 patients (83.1%) were adults. 47 (44.3%) of the 106 children had neurogenic tumors, while 21 patients (19.8%) had a teratoma. 189 (36.2%) of the 522 adults had thymoma and 89 patients (17.1%) had teratoma. In the 106 children there were 71 benign tumor patients (66.9%) and 35 malignant tumor patients (33.1%). There were 277 (53.1%) benign and 245 (46.95) malignant tumors in the 522 adults. The adults had significantly more malignant tumors than the children (p < 0.01). In our series of malignant mediastinal tumors in children, 14 patients (13.3%) had a lymphoma and 11 patients (10.5%) had a neuroblastoma. On the other hand, in the adults, 127 patients (24.3%) had a thymoma and 66 patients (12.6%) had a lymphoma. Regarding benign mediastinal tumors, in children, 30 patients (28.5%) had a ganglioneuroma and 19 patients (18.0%) had a teratoma. In the adults, 68 patients (13.0%) had a teratoma and 62 patients (11.9%) had a thymoma. In the clinical manifestation, 51 child patients (48.1%) and 191 adult patients (36.6%) were asymptomatic. As symptoms due to compression or direct invasion to adjacent structures, dyspnea was seen in 16 child patients (15.1%), and chest pain occurred in 59 adult patients (11.3%). Dyspnea was significantly more common in children than in in adults (p < 0.01). Emergency operations were performed in children more than in adults.

In vitro and in vivo activities of Q-35, a new fluoroquinolone, against Mycoplasma pneumoniae

The in vitro potency and in vivo efficacy of Q-35, a new fluoroquinolone, against Mycoplasma pneumoniae were investigated by pharmacokinetic studies with M. pneumoniae-infected hamsters. By using fluoroquinolones, macrolides, and tetracyclines as references, Q-35 was found to possess the greatest mycoplasmacidal activity. The MIC for 90% of strains tested (MIC90) and the MIC50 were 0.78 and 0.39 microgram/ml, respectively, and the MBC for 90% of strains tested (MBC90) and the MBC50 were 3.13 and 0.78 microgram/ml, respectively. The MBC50-to-MIC50 ratio for Q-35 was 2. Furthermore, only Q-35 continued to be effective against 19 strains of erythromycin-resistant mutants of M. pneumoniae. The efficacies of fluoroquinolones against M. pneumoniae were also investigated by using an experimental hamster pneumonia model to measure the CFU of M. pneumoniae in the lungs. Q-35 and ofloxacin were efficacious following oral administration of 200 mg/kg/day for 5 days, initiated 24 h after infection, while ciprofloxacin was not active. Continuous administration of Q-35 for 10 days significantly reduced numbers of viable M. pneumoniae in the lungs. These results suggest that both Q-35 and ofloxacin are effective in the early phase of infection and, moreover, that Q-35 is also effective in the middle stage of infection, when progressive lung alterations and continuous increases in mycoplasmal growth occur. Peak levels of Q-35 in sera and lungs after oral administration were higher than those of ciprofloxacin but lower than those of ofloxacin. On the basis of these results, Q-35 appears to be a promising antimicrobial agent in chemotherapy of mycoplasmal infection.

Induction of macrophage-mediated production of tumor necrosis factor alpha by an L-form derived from Staphylococcus aureus

We investigated the capability of an L-form derived from Staphylococcus aureus to induce tumor necrosis factor alpha (TNF-alpha) production in murine peritoneal macrophages. The activity for TNF-alpha induction was found in the membrane fraction of the L-form but not in the cytoplasmal fraction purified by the sucrose step gradient centrifugation. TNF-alpha mRNA was also detected in macrophages stimulated with L-form membranes. L-form induced TNF-alpha production in macrophages from both lipopolysaccharide-responsive and -unresponsive mouse strains. Regardless of the presence of polymyxin B, the activity of TNF-alpha induction of L-form was mostly found in the phenol layer, but not in the aqueous layer, both of which were prepared by phenol extraction method. Fractions of L-form membranes representing molecular masses of approximately between 29 and 36 kDa were primarily responsible for inducing the production of TNF-alpha consistently. Moreover, this stimulatory effect was abolished by digestion with Streptomyces griseus protease. In Western blot (immunoblot) analysis with anti-lipoteichoic acid antibody, two bands (65 and 45 kDa) were observed in the sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the phenol layer, whereas one band (14 kDa) was observed in either the aqueous layer or lipoteichoic acid of S. aureus. These results suggest that the component in the membrane of the L-form, distinct from cell wall components such as teichoic acid or lipopolysaccharide, possesses the capability to stimulate TNF-alpha production by macrophages.

Effects of new quinolones on Mycoplasma pneumoniae-infected hamsters

The efficacies of the new quinolones temafloxacin, ofloxacin, and ciprofloxacin were investigated against Mycoplasma pneumoniae in an experimental hamster pneumonia model. Hamsters were infected intratracheally with M. pneumoniae and sacrificed 18 h after the final medication, and their lungs were aseptically removed, homogenized, and cultured quantitatively. The efficacies of these drugs were determined by the CFU of M. pneumoniae in lungs. Temafloxacin and ofloxacin, but not ciprofloxacin, were active when the oral administration of 200 mg/kg of body weight per day (once per day) for 5 days was initiated 24 h after infection. Although no effect on the elimination of M. pneumoniae was observed after the administration of these drugs at 200 mg/kg/day at 5 days after infection, the continuous administration for 15 days of temafloxacin, but not ofloxacin or ciprofloxacin, significantly reduced viable M. pneumoniae in the lungs. These results suggest that temafloxacin and ofloxacin are effective in the acute phase of infection and, moreover, that temafloxacin is effective in the late stage of infection during which progressive lung alterations and continuous increases in mycoplasmal growth occurred. The peak levels of temafloxacin in sera and lungs after oral administration were similar to those of ofloxacin and higher than those of ciprofloxacin. The areas under the curve of temafloxacin in the lung tissue, however, were higher than those of ofloxacin and ciprofloxacin. On the basis of these results, temafloxacin and ofloxacin might be promising antimicrobial agents for the treatment of mycoplasmal infection.

Attenuation of warm ischemic injury of rat lung by inflation with room air--assessment of cellular components and the surfactant in the bronchoalveolar lavage fluid in relation to changes in cellular adenosine triphosphate

Studies were made on the effects in rat lungs of aerobic and anaerobic conditions on the intracellular levels of adenosine triphosphate and its related metabolites, the releases of intracellular enzymes, and the secretion of pulmonary surfactant. After warm ischemia for 120 min, the ATP content of lungs inflated with air was significantly higher (8.0 +/- 1.2 mumol/g dry weight) than those of deflated lungs and lungs inflated with nitrogen (0.8 +/- 0.7 mumol/g dry weight and 2.0 +/- 0.7 mumol/g dry weight, respectively; P < 0.001). The amounts of intracellular enzymes, such as lactate dehydrogenase, cytosolic and mitochondrial aspartate aminotransferase, and protein in the bronchoalveolar lavage fluid (BALF) of air-inflated lungs were significantly less than those in BALFs of deflated and nitrogen-inflated lungs (P < 0.001). The BALF-contents of dipalmitoyl phosphatidylcholine (DPPC), the main component of alveolar surfactant of aerobic and anaerobic ischemic lung were, however, similar. During 120-min warm ischemia after lavage, air-inflated lungs secreted significantly more DPPC into the alveolar space than nitrogen-inflated lungs did (P < 0.001). We conclude that cell membranes in the lungs are damaged under anaerobic conditions, but that inflation of ischemic lungs with air is effective for protecting them from cell injury and for maintaining the intracellular level of ATP and the ability of the cells to secrete pulmonary surfactant.

Stability constants of Ca-alkyl salicylate complexes and their effect on the dissolution of calcium hydroxide dental cements

The proton-ligand stability constants (pKa) and Ca-ligand stability constants (log beta) of the five types of alkyl salicylate were determined and the dissolution of the calcium hydroxide cements prepared from those salicylates was examined in water. The dissolution of the cements containing monoesters decreased with the increase in their pKa and log beta values. The cement containing diester showed lower dissolution than that estimated from those values. This seems to be related to the polymeric structure of the cement matrix consisting of the complex of the diester with calcium.

Erosion process of calcium hydroxide cements in water

Erosion process of calcium hydroxide cements was examined for 7 days by chemical analysis of eluates and observation of structural change of the eroded cements when the cements were immersed in water at 37 degrees C. The elution of salicylate from the set cements as well as that of Ca continued during the immersion time. In the early stage of the erosion, unreacted Ca(OH)2 was preferentially extracted from the cements in comparison with Ca-alkyl salicylate chelate of the cement matrix. The elution rate of N-ethyl o- and p-toluene sulphonamides, which were contained as plasticizer, was higher than those of Ca and salicylate. Insoluble inorganic filler remained at the surface of the cements after extraction of unreacted Ca(OH)2 and disintegration of the cement matrix. Types of salicylate ester seemed to affect the cement durability.

Filtration coefficient in isolated preserved and reperfused canine lung

The filtration coefficient (Kf) in Starling's equation for fluid exchange was estimated in isolated reperfused canine lobes to evaluate the effect of ischemia-reperfusion injury on alveolar-capillary permeability quantitatively and to determine the inhibitory effects of a high dose of methylprednisolone (MPS) or dimethylthiourea (DMTU), a potent hydroxyl radical scavenger, on this injury. We reperfused isolated canine left lower lobes (LLLs) with blood at a constant flow after 3 hr of warm (38 degrees C) or cold (4 degrees C) ischemia and measured Kf after 1 hr of reperfusion. The mean value of Kf (+/- 1 SD) in the cold ischemic lobes (COLD, n = 7), 0.13 +/- 0.04 g.min-1.cmH2O-1.100 g-1, was not different from that in the control nonischemic lobes (CONT, n = 6), 0.10 +/- 0.04 g.min-1.cmH2O-1.100 g-1. In contrast, the mean value of the Kf in the warm ischemic lobes (WARM, n = 7), 0.38 +/- 0.17 g.min-1.cmH2O-1.100 g-1, was significantly (P less than 0.001) higher than in CONT.MPS (30 mg/Kg) or DMTU (0.75 g/kg) administered before isolation of LLL and before reperfusion reduced the increase in Kf in warm ischemic lobes to 0.19 +/- 0.09 and 0.19 +/- 0.05 g.min-1.cmH2O-1.100 g-1, respectively (P less than 0.005 WARM vs MPS, and P less than 0.01 WARM vs DMTU). MPS and DMTU also attenuated the impairment of gas exchange. We conclude that (1) reperfusion after 3 hr of warm ischemia increases Kf but after cold ischemia does not, and (2) MPS and DMTU prevent the increase in Kf.(ABSTRACT TRUNCATED AT 250 WORDS)

Protective effect of DM-9384, a novel pyrrolidone derivative, against experimental cerebral anoxia

The protective effects of DM-9384 [N-(2,6-dimethylphenyl)-2-(2-oxo- 1-pyrrolidinyl) acetamide] against cerebral anoxia were investigated using various animal models. Oral administration of DM-9384 resulted in a significant prolongation of survival time in mice and rats subjected to the normobaric hypoxia; its minimal effective doses were 30 and 10 mg/kg, respectively. A significant protection by this drug against hypobaric hypoxia, histotoxic anoxia and cerebral ischemia also occurred in mice at a dose of 100 mg/kg, p.o. Bifemelane (100-300 mg/kg, p.o.) was protective against these models except for hypobaric hypoxia, and the effects of piracetam, aniracetam and pramiracetam (1000 mg/kg, p.o.) were variable depending on the type of anoxia model used. DM-9384 (100 mg/kg and lower) attenuated the hypolocomotion and the disturbance of cerebral energy metabolism such as a decrease in ATP, an increase in lactate and lactate/pyruvate ratio induced by hypoxia in rats. The spontaneous motor activity, uptake and utilization of brain glucose in normal animals, however, were not influenced by this drug. Based on these results, DM-9384 is characterized as a broad spectrum anti-anoxic drug with negligible CNS depression, and the cerebral protective effect of this drug may be, at least in part, attributable to its ability to improve the cerebral energy metabolic disturbance.

Intrinsic pressor activity of midaglizole, an alpha-2 adrenoceptor antagonist, in pithed rats

Midaglizole (3 and 30 mg/kg, i.v.) increased blood pressure in pithed rats. The pressor response was not inhibited by intravenous prazosin (0.3 mg/kg), yohimbine (1 mg/kg), ketanserin (1 mg/kg) or diphenhydramine (5 mg/kg). Diltiazem (1 mg/kg) antagonized the hypertension. Idazoxan (10 mg/kg) also increased blood pressure, and the pressor response was inhibited by prazosin, but not by yohimbine. These results suggest that the vascular effect of midaglizole is due to a mechanism different from that of idazoxan.

Effects of antihypertensive drugs on experimental cerebral ischemia in spontaneously hypertensive rats

The effects of antihypertensive drugs on ischemic cerebral damage were investigated using the bilateral carotid artery occlusion (BCAO) model in SHR. Oral budralazine and nifedipine, at doses that increased cerebral blood flow (CBF) in SHR in our previous study (Tanaka, S. et al., Folia Pharmacol, Japan, 87, 1986), significantly improved cerebral energy failure after the BCAO, but prazosin which does not increase CBF had no effect on the energy failure. These results suggest that the amelioration by these antihypertensive drugs of the energy failure after the BCAO results from its CBF-increasing effects in SHR.

Alpha 2-adrenoceptor-blocking properties of midaglizole (DG-5128) in rats

The alpha 2-adrenoceptor antagonistic potency of midaglizole was evaluated and compared with that of the selective alpha 2-adrenoceptor antagonists yohimbine and idazoxan. Intravenously administered midaglizole, like yohimbine and idazoxan, reversed the clonidine-induced inhibition of the tachycardic response to cardiac nerve stimulation in pithed rats. Midaglizole, yohimbine and idazoxan inhibited the pressor responses to B-HT 920 (alpha 2-adrenoceptor agonist), in a dose-related manner, to a greater extent than the response to methoxamine (alpha 1-adrenoceptor agonist). Conversely, prazosin produced a highly selective antagonism of the methoxamine-evoked response in this preparation. Midaglizole failed to antagonize centrally mediated hypotension and bradycardia induced by intravenous clonidine, whereas the other alpha 2-antagonists attenuated the clonidine-induced cardiovascular responses in intact rats. These results suggest that midaglizole is a selective alpha 2-adrenoceptor antagonist and, unlike yohimbine and idazoxan, is characterized by its ability to block peripheral but not central alpha 2-adrenoreceptors when administered systemically.

Antiulcer effects of 3-[[[2-(3,4-dimethoxyphenyl)ethyl] carbamoyl]methyl]-amino-N-methylbenzamide in experimental gastric and duodenal ulcers

Effects of 3-[[[2-(3,4-dimethoxyphenyl)ethyl]carbamoyl] methyl]-amino-N-methylbenzamide (DQ-2511), a newly synthesized compound, were evaluated using various types of experimental gastric and duodenal ulcers in rats. Pretreatment with DQ-2511, over the dose range 30-300 mg/kg p.o., resulted in a dose-related inhibition of water-immersion stress-, serotonin-, acetylsalicylic acid (ASA)-, indometacin-, ethanol-, and 2-deoxy-D-glucose(2DG) plus indometacin-induced gastric ulcers as well as cysteamine-induced duodenal ulcers. The antiulcer potencies of DQ-2511 were equal to or greater than those of H2-receptor antagonist cimetidine in these ulcer models except for ASA- and 2DG plus indometacin-induced ulcers. The rate of healing of chronic gastric ulcers induced by acetic acid was significantly accelerated by DQ-2511 (100 and 300 mg/kg p.o.) but not by the same doses of cimetidine. DQ-2511, at doses of 30 mg/kg p.o. and above, produced a significant decrease in gastric acid and pepsin output in pylorus-ligated rats. In anesthetized rats with acute gastric fistulae, 30 mg/kg i.v. of DQ-2511 significantly inhibited gastric acid secretion stimulated by 2DG, whereas it did not affect gastric hyperacidity evoked by either carbachol, histamine or pentagastrin. At effective antiulcer doses, this compound produced a sustained increase in gastric mucosal blood flow in conscious, restrained rats. Based on these observations, DQ-2511 is characterized as a new antiulcer compound with beneficial effects on both gastric aggressive and defensive factors. Furthermore, these results indicate a possible superiority of DQ2511 over cimetidine in regard to its antiulcer potency and spectrum.

Influence of antihypertensive treatment with budralazine on autoregulation of cerebral blood flow in spontaneously hypertensive rats

We studied the effect of chronic antihypertensive treatment with budralazine on the lower blood pressure limit of cerebral blood flow autoregulation using spontaneously hypertensive rats. Cerebral blood flow in the parietal cortex and caudate nucleus was measured to determine the lower limit using the hydrogen clearance method. The lower limit in both cerebral regions was significantly higher in 10 untreated spontaneously hypertensive rats than in 10 Wistar-Kyoto rats. The upward-shifted lower limit was restored to close to normal in the caudate nucleus and was partially restored in the parietal cortex of nine rats by 9 weeks of treatment with the high dose (50-68 mg/kg/day) of budralazine, which kept blood pressure constant at approximately normotension during the treatment period; the lower limit was slightly restored in both cerebral regions of seven rats by 4 weeks of treatment with the high dose. However, 9 weeks of treatment with the low dose (19-27 mg/kg/day) of budralazine, which produced moderate continuous hypotension in nine rats, did not apparently influence the lower limit. Our results suggest that long-term antihypertensive therapy with budralazine reduces the upward-shifted lower blood pressure limit of cerebral blood flow autoregulation toward normal and that the restoration induced by budralazine depends on the degree of blood pressure reduction as well as on the duration of the therapeutic period.

[Serum and tissue concentration of tegafur and 5-FU after administration of tegafur suppository in patients with lung cancer--correcting the influence of residual blood in the tissue]

Tissue concentration of tegafur and 5-FU was studied in 25 patients with of primary lung cancer, given 2 x 750 mg of tegafur suppository daily preoperatively (total doses 3.75-9.75 g, mean 5.16 g). Furthermore, the influence of blood remaining in the tissue was corrected in the determination of tegafur and 5-FU concentration. The tegafur level in tumor tissue (9.614 +/- 5.739 micrograms/g) was significantly (p less than 0.01) low compared with those in serum and normal lung tissue (13.185 +/- 8.198 micrograms/ml, 12.954 +/- 10.048 micrograms/g). On the other hand, the 5-FU level in tumor tissue (0.124 +/- 0.208) was significantly (p less than 0.01, p less than 0.05) high compared with those in serum and normal lung tissue (0.019 +/- 0.013 micrograms/ml, 0.035 +/- 0.031 micrograms/g) and showed approximately 2.5 times more minimum effective concentration against tumor cells (0.05 micrograms/g). The results show that preoperative administration of 2 x 750 mg of tegafur suppository daily is effective for the transfer of tegafur and 5-FU to lung cancer tissue.

[Complication related to operative procedure in lung cancer and mediastinal malignancy--report of 6 cases]

Of the patients who underwent surgical treatment for the respiratory system at our hospital over the past 9 years, 6 were postoperatively complicated with chylothorax, 1 with liquorrhea and the other one with paraplegia. Chylothorax occurred after mediastinal lymph node dissection which was carried out for the treatment of malignant tumors. In five cases, it occurred on the left side, and in the sixth case, it occurred on the right side. In 2 patients who received conservative treatment, there was no reduction in chyle outflow, and they died of cerebral infarction and sepsis. The other 4 cases were surgically treated. In 3 of them, the impaired site of the thoracic duct was confirmed by administration of Sudan III before surgery. We confirmed that early reoperation for the chylothorax after lung resection should be performed. Liquorrhea occurred from the 5th costvertebral joint which had been directly infiltrated by lung carcinoma. Fortunately, the postoperative course was uneventful, though the patient complained of dizziness and headache until 14 postoperative days. The case of paraplegia was caused by oxydized cellulose cotton that entered the epidural space via the intervertebral foramen. It was used for hemostasis in the 5th costvertebral joint. This case indicates that oxydized cellulose cotton, which swells when it absorbs water, should be carefully used for hemostasis around the nerves.

[The effect of an antihypertensive drug budralazine on cerebrovascular lesions in salt-loaded SHR]

Budralazine was evaluated for its protective effect on the onset of cerebrovascular lesions in SHR given 1.5% NaCl as drinking water. The salt-loading for 67 days rapidly accelerated the development of hypertension in SHR (from 180 to over 250 mmHg, 40 days after the loading). The acceleration of hypertension was accompanied by an increase in the incidence of brain softening, cerebral infarct, angionecrosis and hemorrhage by 30-60% following the thrombosis and necrosis of cerebral arterioles. Renal angionecrosis associated with the interstitial nephrosis was also observed by 90% in the animals. Throughout the salt-loading period, oral administration of budralazine (1, 4 and 15 mg/kg/day) resulted in a dose-dependent inhibition of the accelerated hypertension. At larger doses (4 and 15 mg/kg/day), budralazine almost completely ameliorated the cerebral and renal lesions and significantly attenuated the rise of weight in the brain and heart observed in the salt-loaded control rats. Changes in the serum biochemical findings were also inhibited by this drug. In some of the parameters measured, budralazine appeared to be more efficacious than hydralazine (1, 4 and 15 mg/kg/day, p.o.). These results suggest that budralazine attenuates the serious development of hypertension and reduces the incidence and severity of stroke in salt-loaded SHR.

Effects of N-(2,6-dimethylphenyl)-2-(2-oxo-1-pyrrolidinyl)acetamide (DM-9384) on learning and memory in rats

Effects of N-(2,6-dimethylphenyl)-2-(2-oxo-1-pyrrolidinyl) acetamide (DM-9384) on learning and memory were studied using four different experimental rat models. In electroconvulsive shock- or scopolamine-induced amnesia in the step-through passive avoidance task, DM-9384 improved both types of amnesia when administered before the training trial. Aniracetam also showed similar but somewhat weaker effects. Furthermore, in the scopolamine amnesia model, an improvement was confirmed with arecoline. The dose-response curves for these compounds were bell-shaped. In the shuttle box active avoidance task, DM-9384 administered daily 1 hr before each training session facilitated the acquisition process of the avoidance response. In addition, the experiment of light-dark discrimination task with positive reinforcement showed that this compound administered daily after each session slightly accelerated the acquisition process of the correct response. These results suggest an ability of DM-9384 to enhance cognitive functions.

[Study on indication of unilateral pulmonary artery occlusion test in patients undergoing pneumonectomy]

We tried to establish an indication of unilateral pulmonary artery occlusion test (UPAO), by analyzing the preoperative data of UPAO, overall and regional pulmonary function tests, and arterial blood gas in 55 patients who were intended for pneumonectomy. Our limits of functional indication for pneumonectomy were PPA less than or equal to 25 mmHg or TPVRI less than or equal to 700 dyne.cm-5.m2. PPA correlated with the inverse of contralateral FEV1.0/BSA (FEV section 1.0) and DLCO/BSA (section DLCO), which were calculated by multiplying preoperative values by contralateral ventilation fraction. TPVRI correlated with age, the inverse of PaO2, the inverse of FEV section 1.0, and the inverse of section DLCO. Multiple regression analysis yielded the equation, TPVRI approximately p = 1120/section DLCO + 24800/PaO2 + 6.40 X Age -506. In order to make false negative zero, the values of each parameter were as follows: age greater than or equal to 55, PaO2 less than or equal to 85 mmHg, FEV section 1.0 less than or equal to 0.8 L/m2, section DLCO less than or equal to 6.0 ml/min/mmHg/m2 and TPVRI approximately p greater than or equal to 450 dyne.sec.cm-5.m2. The specificities of each parameter were 18.6%, 20.9%, 39.2%, 40.4% and 59.0%. Therefore, in order to make false positive patients least, the criteria of TPVRI approximately p greater than or equal to 450 dyne.sec.cm-5.m2 should be used.

[The result of extended thymectomy in patients with myasthenia gravis of pure ocular type]

We studied postoperative status of 14 patients with myasthenia gravis of ocular type who underwent extended thymectomy. Nine patients were in remission, three improved, and two unchanged. No patient became worse and died. The remission rates at one, three, five, and ten years after operation were 50.0%, 58.3%, 60.0%, and 80.0%. The palliation rates at one, three, five, and ten years after operation were 64.3%, 75.0%, 80.0%, and 100%. The remission rate at one year after operation in patients of ocular type was significantly (p less than 0.05) higher than that in generalized type (191 patients). The mean preoperative duration of symptoms in patients who obtained remission after surgery was 7.2 +/- 6.5 months, while mean duration was 85.6 +/- 45.8 months in those patients who could not obtain remission, indicating a significant difference (p less than 0.05) of duration of symptoms between two groups. Among 89 patients with generalized as well as ocular symptoms before extended thymectomy, 62 patients (69.7%) still complained of ocular symptoms and 48 patients (53.9%) had generalized symptoms with or without ocular symptoms in 1 to 12 years after operation. This result shows that ocular symptoms do not disappear more easily than generalized ones. We conclude that extended thymectomy should be performed even in patients with myasthenia gravis of pure ocular type.

Prediction of postoperative respiratory failure in patients undergoing lung resection for lung cancer

To evaluate the correlation between predicted postoperative lung function and postoperative respiratory morbidity, 156 patients with lung cancer who underwent resection were classified into four groups based on the degree of postoperative problems: Group 1--no problems (116 patients); Group 2--retention of sputum or atelectasis requiring bronchofiberscopy two or more times (17 patients); Group 3--tracheostomy or mechanical ventilation for more than 2 days or both (14 patients); and Group 4--postoperative death (9 patients). The mean ages of Groups 2, 3, and 4 were significantly (p less than 0.05) higher than the mean age of Group 1. The predicted postoperative lung function (F) was assessed by the formula F = [1-(b-n)/(42-n)] x f, where f is the preoperative vital capacity or forced expiratory volume in one second, b is the number of subsegments of the resected lung lobe, and n is the number of subsegments obstructed by the tumor, which was assessed by the findings on the chest tomogram, on the bronchogram, at bronchofiberscopy, or a combination of these. The total number of subsegments was assumed to be 42. The predicted postoperative % FEV1 was 65.1 +/- 19.3% in Group 1,55.3 +/- 10.6% in Group 2,37.6 +/- 12.1% in Group 3, and 42.3 +/- 18.4% in Group 4. It was significantly (p less than 0.05) different between all the groups except between Groups 3 and 4. All 10 patients with a predicted postoperative % FEV1 of less than 30% were in Groups 3 and 4. We conclude that special attention to postoperative management is needed for patients whose predicted postoperative %FEV1 is lower than 30%.

Molecular cloning and expression of a gene for a factor which stabilizes formation of inhibitor-mitochondrial ATPase complex from Saccharomyces cerevisiae

Stabilizing factor, a 9 kDa protein, stabilizes and facilitates formation of the complex between mitochondrial ATP synthase and its intrinsic inhibitor protein. A clone containing the gene encoding the 9 kDa protein was selected from a yeast genomic library to determine the structure of its precursor protein. As deduced from the nucleotide sequence, the precursor of the yeast 9 kDa stabilizing factor contains 86 amino acid residues and has a molecular weight of 10,062. From the predicted sequence we infer that the stabilizing factor precursor contains a presequence of 23 amino acid residues at its amino terminus. We also used S1 mapping to determine the initiation site of transcription under glucose-repressed or derepressed conditions. These experiments suggest that transcription of this gene starts at three different sites and that only one of them is not affected by the presence of glucose.

Cholinergic innervation of the main and the accessory olfactory bulbs of the rat as revealed by a monoclonal antibody against choline acetyltransferase

The main and accessory olfactory bulbs (MOB and AOB) of the rat were immunohistochemically stained with a monoclonal antibody against choline acetyltransferase (ChAT) in order to know the difference in the distribution patterns of cholinergic fibers between these two structures. A few ChAT-immunoreactive cell bodies were found in the superficial and middle parts of the external plexiform layer (EPL) of the MOB, in the granule cell layer (GCL) of the MOB, and in the GCL of the AOB. The frequency in appearance of these cells was 0.9 cells/section in the MOB and 0.3 cells/section in the AOB. While the glomerular layer (GL) and the superficial part of the EPL were most densely innervated in the MOB, the internal plexiform layer received the richest innervation in the AOB. There were no immunoreactive structures in the olfactory nerve layer of the MOB and in the vomeronasal nerve layer and glomerular layer of the AOB. In addition to a relatively homogenous distribution of cholinergic fibers in the MOB and AOB, there were several foci of very dense network of immunoreactive fibers at the posterior level of the OB. These foci formed a part of the modified glomerular complex that was recently identified using 2-deoxyglucose method and was presumed to be related to suckling behaviour in the neonatal rat.