Quantitative analysis of changes in blood concentrations and 'presumed effect-site concentration' of sevoflurane during one-lung ventilation

During one-lung ventilation, ventilation-perfusion mismatch decreases the arterial concentration of inhaled anaesthetics due to the arterial-to-venous concentration difference. This study tested the hypothesis that in humans, the 'presumed effect-site concentration' (taken as the mid-point between the arterial and superior jugular venous concentrations) of inhaled anaesthetic falls during one-lung (vs two-lung) ventilation. Four patients scheduled for elective prostatectomy (two-lung ventilation) and four patients for elective thoracotomy (one-lung ventilation) were randomly selected and assigned to receive sevoflurane (vaporiser-dial setting, 1.5%). Sevoflurane concentrations were measured periodically from radial artery and superior jugular vein (via a catheter advanced cephalad from the jugular vein). During one-lung ventilation, the end-expiratory sevoflurane concentration was stable at ∼1.3% but the mean (SD) presumed effect-site concentration declined initially from 58 (6.7) to 43 (4.7) μg.ml(-1) (p=0.011) before slowly recovering. A period of insufficient depth of anaesthesia is thus a risk during one-lung ventilation.

Tumour necrosis factor alpha signalling through activation of Kupffer cells plays an essential role in liver fibrosis of non-alcoholic steatohepatitis in mice

BACKGROUND

While tumour necrosis factor alpha (TNF-alpha) appears to be associated with the development of non-alcoholic steatohepatitis (NASH), its precise role in the pathogenesis of NASH is not well understood.

METHODS

Male mice deficient in both TNF receptors 1 (TNFR1) and 2 (TNFR2) (TNFRDKO mice) and wild-type mice were fed a methionine and choline deficient (MCD) diet or a control diet for eight weeks, maintaining isoenergetic intake.

RESULTS

MCD dietary feeding of TNFRDKO mice for eight weeks resulted in attenuated liver steatosis and fibrosis compared with control wild-type mice. In the liver, the number of activated hepatic Kupffer cells recruited was significantly decreased in TNFRDKO mice after MCD dietary feeding. In addition, hepatic induction of TNF-alpha, vascular cell adhesion molecule 1, and intracellular adhesion molecule 1 was significantly suppressed in TNFRDKO mice. While in control animals MCD dietary feeding dramatically increased mRNA expression of tissue inhibitor of metalloproteinase 1 (TIMP-1) in both whole liver and hepatic stellate cells, concomitant with enhanced activation of hepatic stellate cells, both factors were significantly lower in TNFRDKO mice. In primary cultures, TNF-alpha administration enhanced TIMP-1 mRNA expression in activated hepatic stellate cells and suppressed apoptotic induction in activated hepatic stellate cells. Inhibition of TNF induced TIMP-1 upregulation by TIMP-1 specific siRNA reversed the apoptotic suppression seen in hepatic stellate cells.

CONCLUSIONS

Enhancement of the TNF-alpha/TNFR mediated signalling pathway via activation of Kupffer cells in an autocrine or paracrine manner may be critically involved in the pathogenesis of liver fibrosis in this NASH animal model.

Interleukin-6 concentrations in the placenta and blood in normal pregnancies and preeclampsia

AIM

To evaluate whether IL-6 concentrations in the placenta and blood from women with preeclampsia differed from those in normal pregnancies.

METHODS

This study involved 41 pregnant women carrying single fetuses. Of these pregnancies, 23 were normal pregnant and 18 were preeclamptic patients. The average gestational age at entry was 37-38 weeks of gestation. Blood was collected before the onset of labor. Serum was separated and stored at -20 degrees C. A tissue segment of the placenta was cut and chilled in liquid nitrogen immediately after delivery and stored at -80 degrees C. The frozen tissue was added to phosphate-buffered saline and fully homogenized. After centrifugation, the separated supernatant was stored at -80 degrees C. IL-6 levels in separated serum and IL-6 and total protein (TP) levels in separated supernatant were measured. The presence of IL-6 in the placenta was evaluated by immunohistochemistry in five preeclamptic and five normal pregnant patients.

RESULTS

Neither IL-6/TP levels in the placenta nor IL-6 levels in blood differed significantly between the two groups. IL-6 immunostaining on trophoblastic cells in the placenta was weak in one and absent in four in normal pregnancies, and absent in all patients with preeclampsia. There was no strong immunostaining for IL-6 in preeclampsia by immunohistochemistry.

CONCLUSIONS

Our findings suggest that IL-6 in the placenta and blood does not play a significant role in the induction of an immunologic imbalance, which may contribute to the etiological mechanism leading to preeclampsia.

Undifferentiated endometrial carcinoma of the uterus: marked effect of chemotherapy with tetrahydropyranyl-adriamycin, paclitaxel, and carboplatin

Undifferentiated endometrial carcinoma of the uterus is rare, and is thought to show a poor prognosis. To date, there is no consensus as to the optimal chemotherapy for this carcinoma. We report a rare case of this carcinoma in a patient who was treated surgically in combination with chemotherapy using a regimen designed by us. This chemotherapy consists of tetrahydropyranyl-adriamycin, paclitaxel, and carboplatin. This regimen is called TTJ [tetrahydropryanyl-adriamycin, taxan (paclitaxel), JM-8 (carboplatin)] chemotherapy and showed a marked effect. The patient was a 52-year-old woman with a giant tumor of the uterus measuring 28 x 18 x 13 cm and weighing 3386 g. She underwent total abdominal hysterectomy with bilateral salpingo-oophorectomy and omentectomy, but residual carcinoma remained on the surface of the small intestine. Pathologically tumor tissues comprised the whole uterus except for the uterine cervix and there were tumor tissues in the omentum. She was treated with six courses of TTJ chemotherapy without major side-effects. Currently, she remains alive without metastasis 41 months after hysterectomy. This report describes a rare case of undifferentiated endometrial carcinoma of the uterus and introduces TTJ chemotherapy resulting in the remarkable effect on this carcinoma.

Undifferentiated endometrial carcinoma of the uterus: marked effect of chemotherapy with tetrahydropyranyl-adriamycin, paclitaxel, and carboplatin

Undifferentiated endometrial carcinoma of the uterus is rare, and is thought to show a poor prognosis. To date, there is no consensus as to the optimal chemotherapy for this carcinoma. We report a rare case of this carcinoma in a patient who was treated surgically in combination with chemotherapy using a regimen designed by us. This chemotherapy consists of tetrahydropyranyl-adriamycin, paclitaxel, and carboplatin. This regimen is called TTJ [tetrahydropryanyl-adriamycin, taxan (paclitaxel), JM-8 (carboplatin)] chemotherapy and showed a marked effect. The patient was a 52-year-old woman with a giant tumor of the uterus measuring 28 × 18 × 13 cm and weighing 3386 g. She underwent total abdominal hysterectomy with bilateral salpingo-oophorectomy and omentectomy, but residual carcinoma remained on the surface of the small intestine. Pathologically tumor tissues comprised the whole uterus except for the uterine cervix and there were tumor tissues in the omentum. She was treated with six courses of TTJ chemotherapy without major side-effects. Currently, she remains alive without metastasis 41 months after hysterectomy. This report describes a rare case of undifferentiated endometrial carcinoma of the uterus and introduces TTJ chemotherapy resulting in the remarkable effect on this carcinoma.

Increased levels of serum macrophage colony-stimulating factor before the onset of preeclampsia

Macrophage colony-stimulating factor (M-CSF) is known to play a central role in maintaining pregnancy. The present study determined whether the increase in serum M-CSF levels preceded the onset of preeclampsia. Blood was collected from 110 normotensive pregnant women at risk for preeclampsia who were carrying single fetuses at about 30 weeks of gestation. After centrifugation, serum was stored at -20 degrees C until assay. Eighteen women developed preeclampsia at a later stage of pregnancy (group 1), while 88 women continued to have normotensive pregnancies until delivery. Thirty-four of the 88 women with normotensive pregnancy who were matched for age and parity were selected to form a control group (group 2). Serum M-CSF levels were determined by the sandwich ELISA method using three antibodies. Serum level of M-CSF was 1,266 U/ml (median) in group 1 and 1,082 U/ml in group 2. Serum M-CSF levels were significantly higher in group 1 than in group 2 (p < 0.0002). Increased levels of serum M-CSF markedly precede the development of clinical manifestations of preeclampsia. High serum M-CSF levels support M-CSF elevation in the placenta. This elevation at 30 weeks of gestation may be associated with placental hypoxia, which is considered the cause of preeclampsia.

Platelet aggregation response and adenosine triphosphate secretion after abdominal total hysterectomy

This study was designed to clarify the quantitative relationship between platelet aggregation and the secretion of adenosine triphosphate (ATP) after surgery. Peripheral blood was collected from 41 patients who underwent abdominal total hysterectomy. Platelet count, volume, aggregation and the amount of secreted ATP were determined using live platelets before, one day after and two weeks after surgery. Platelet aggregation and ATP secretion were investigated using a lumi-aggregometer. The aggregating reagents used were 5 microM of adenosine diphosphate (ADP) (final concentration) and 5 microg/ml of collagen. Structural alterations of platelets at these time points were also investigated by electron microscopy. Platelet aggregation induced by collagen was significantly lower (p<0.05) one day after surgery. ADP-induced aggregation two weeks after surgery was more intense than before (p<0.05) and one day after (p<0.05) surgery. The amount of secreted ATP induced by each of ADP and collagen was significantly lower (p<0.05-0.01) one day after surgery and correlation coefficients between platelet aggregation and secretion of ATP showed lower values in both ADP- and collagen-induced aggregation. One day after surgery electron microscopy showed that granule concentrations were markedly reduced in platelets. In conclusion, after consumption of circulating platelets at the site of operation, in addition to being lost by bleeding, the remaining platelets in circulation consist of platelet subpopulations different from those present before surgery, exhibiting low values of correlation coefficients between platelet aggregation and secretion of ATP and low concentrations of granules.

Successful pregnancy following gonadotropin therapy in a patient with hypogonadotropic hypogonadism resulting from craniopharyngioma

The authors report a rare case of a patient with panhypopituitarism who became pregnant by gonadotropin therapy and gave birth to a healthy baby. A brain tumour and/or the surgical resection of a brain tumour occasionally results in pituitary dysfunction. An 18-year-old Japanese patient developed hypogonadotropic secondary amenorrhoea because of a craniopharyngioma, which was surgically removed. The patient came to us, and peripheral blood was collected every 15 minutes for four hours. The levels of luteinising hormone (LH) and follicle-stimulating hormone (FSH) were measured. Results showed that LH and FSH levels were very low and did not fluctuate. Several years later, the patient complained of infertility, and treatment with human menopausal gonadotropin (hMG) and human chorionic gonadotropin (hCG) was started. The therapy was repeated for several cycles, but she did not conceive, so hMG-hCG therapy combined with conjugated oestrogen administration was started. The patient became pregnant at the seventh cycle of this combined therapy. She was not treated with supplementary growth hormone.

Mature adrenomedullin concentrations in plasma during pregnancy

OBJECTIVE

Adrenomedullin is a novel peptide that exerts a potent, dose-dependent and long-lasting hypotensive effect. In human plasma, adrenomedullin consists of two molecular forms: mature and immature. Immature adrenomedullin is much less bioactive than mature adrenomedullin. Although a gradual increase in plasma adrenomedullin has been reportedly observed as pregnancy progressed, mature adrenomedullin has not been examined. The aim of this study was to elucidate the plasma level of mature adrenomedullin in pregnant women.

METHODS

We measured the concentrations of mature adrenomedullin in ten pregnant women in the first trimester, ten pregnant women in the third trimester, and ten non-pregnant controls with the immunoradiometric assay.

RESULTS

The mean concentration of mature adrenomedullin was significantly increased in pregnant women in the first trimester compared to age-matched non-pregnant subjects (p < 0.05). The mean concentration of mature adrenomedullin was significantly increased in pregnant women in the third trimester compared with pregnant women in the first trimester (p < 0.005).

CONCLUSION

Our study demonstrated that concentrations of mature adrenomedullin were elevated in pregnant women compared with non-pregnant women and its concentration in the third trimester was significantly higher than that in the first trimester.

CD26 and CD30 expression on the surface of lymphocyte during normal pregnancy

It is increasingly apparent that the Th1/Th2 cell ratio is decreased during pregnancy. In a previous study, we revealed that combined analysis of soluble CD26 and CD30 might be a potent surrogate tool for evaluating the Th1/Th2 balance during pregnancy. Therefore, in the present study, we elucidated whether the CD26 and CD30 expression on the surface of lymphocyte is useful marker for Th1 and Th2 lymphocytes, respectively, during pregnancy with flow cytometric technique. The peripheral blood samples were obtained from 6 non-pregnant healthy women, 8 healthy pregnant women in the first trimester and 12 pregnant women in the third trimester. The mean percentages of CD26 expression did not differ significantly among these groups (p = 0.45). Also, the mean percentages of CD30 expression did not differ significantly among these groups (p = 0.32). From the present study, the expression of CD26 and CD30 did not appear to be a useful marker for Th1 and Th2 lymphocytes during pregnancy.

Relationship between exploratory eye movements and clinical course in schizophrenic patients

Exploratory eye movements are psychophysiological indicators of schizophrenia as well as smooth pursuit eye movements. To investigate whether these eye movements change in accordance with the clinical course of the condition in schizophrenia, exploratory eye movements (number of eye fixations, mean eye scanning length, responsive search score, evaluation of reproduced Fig. 1 and 2) of 28 schizophrenic patients were evaluated in repeat test design, conducted an average of 8 months apart. Subjects were first-medicated schizophrenics, half were outpatients and the remaining half were inpatients at the Neuropsychiatry ward of Tokyo Medical and Dental University Hospital. Exploratory eye movement patterns did not improve despite an improvement in clinical symptoms of schizophrenia. This result and those of previous studies of the exploratory eye movements of schizophrenic patients' families suggest that exploratory eye movements reflect a schizophrenic vulnerability marker. Furthermore, decreased mean eye scanning length (MESL) values were observed in subjects who showed unimproved symptoms, particularly negative symptoms over an extended period of time. The result suggests that a decrease in the MESL value may be the most sensitive indicator in the development of chronicity in schizophrenia.

[Endoscopic transthoracic sympathectomy (ETS) with a fine 2-mm thoracoscope in palmar hyperhidrosis]

Endoscopic transthoracic sympathectomy (ETS) is an efficient, safe, minimally invasive procedure, and requires only a short period of hospitalization. We performed bilateral ETS using a thoracoscope 2 mm in diameter. We performed 120 ETS for the treatment of palmar hyperhidrosis from August 1997 to April 2000. The patient was placed in the semi-sitting position under general anesthesia, one-lung ventilation being used; the operation was performed with 2-mm two-puncture method. The sympathetic chain could be observed through parietal pleura riding on the costovertebral junctions. A 2-mm Kirschner wire was employed as an electrode, and the second and third thoracic sympathetic chains were electro cauterized. A thoracic drain was not used. The needling sites were only 2 mm in size and could be fixed without suture. For the patient, a small scar of this size means virtually no scar. The operative times were from 11 min to 81 min in bilateral ETS. Immediately and dramatic decrease in the sweat excretion in the palms was noted in all patients. The 95% patients were highly satisfied with the results. The commonest side effects were compensatory sweating. This procedure is recommended as the method of choice for the surgical treatments of palmar hyperhidrosis.

Regulation of dosage of conjugated equine estrogen is useful for add-back therapy

In the hormonal treatment of uterine myomas, which are estrogen dependent, GnRH agonist (GnRHa) therapy has become widespread. However, the severe hypo-estrogenic state induced by the GnRHa gives rise to annoying side effects. Although the risk of these side effects may be reportedly modified when GnRHa is combined with estrogen (add-back therapy), it is difficult to target serum estradiol (E2) concentration to stay within the therapeutic window (20 approximately 50 pg/mL) by administering 0.625 mg conjugated equine estrogen (CEE)/day. Also, there is great individual variation in the circulating E2 concentration by administering the same dosage of CEE. Therefore, the use of smaller quantities of CEE in different dosages may approximate more closely to the clinical situation. This article focuses on the methods of administration of CEE combined with GnRHa for women with symptomatic uterine myomas.

Plasma levels of soluble Fas during normal pregnancy

The Fas/Fas ligand system could reportedly help to identify a mechanism for maternal immunotolerance of the fetus in human pregnancy. However, there are few reports on soluble Fas (sFas) which is an inhibitor of apoptosis during normal pregnancy. Therefore, ascertaining plasma sFas levels during pregnancy would be of interest. The subjects studied were 10 nonpregnant healthy women and 20 healthy pregnant women in the first and third trimester with singleton gestations. The plasma sFas was measured by sandwich enzyme-linked immunosorbent assay. The mean concentration of sFas was significantly decreased in normal pregnant women in the first trimester compared to age-matched control subjects, and it did not differ significantly between normal pregnant women in the third trimester and age-matched control subjects. From these results, we presume that the decreased plasma sFas plays an important role in maternal immunotolerance in the first trimester of pregnancy.

Increased excretion of N-acetyl-beta-D-glucosaminidase and beta2-microglobulin in gestational week 30

BACKGROUND

Little is known about when the urinary excretion of a combination of N-acetyl-beta-D-glucosaminidase (NAG) and beta2-microglobulin (beta2MG) concentration [relative to creatinine (Cr)] reaches maximal values during uncomplicated normotensive pregnancy. This study was thus designed to analyze when urinary excretion of biochemical parameters was increased during normotensive pregnancy.

METHODS

NAG, beta2MG, total protein, albumin, and Cr were simultaneously measured in random (untimed) midstream urine samples from 22 healthy nonpregnant women and from 82 normotensive pregnant women (22 in gestational week 20, 25 in week 30, and 35 in week 37).

RESULTS

NAG/Cr and beta2MG/Cr ratios were significantly higher (P < 0.01-0.05) in the normotensive pregnant women in gestational week 30 than in the nonpregnant control subjects and normotensive pregnant women in gestational week 20. The NAG/Cr and beta2MG/Cr ratios showed maximal values in gestational week 30. The total protein/Cr ratio was significantly higher in gestational weeks 20, 30, and 37 than in the control subjects. The albumin/Cr ratio was significantly higher in women in gestational week 30 and 37 than in women in gestational week 20 and in the control subjects.

CONCLUSIONS

The excretion of both NAG and beta2MG relative to Cr was increased and showed the maximal values in gestational week 30 during normotensive pregnancy. The increase in a tubular enzyme (NAG) might be caused by renal tubular damage, and that in a low molecular weight protein (beta2MG) might result from decreased renal tubular reabsorption. These findings suggest that renal tubular damage and reabsorption dysfunction were increased in gestational week 30.

Changes in plasma soluble CD26 and CD30 during pregnancy: markers of Th1/Th2 balance?

The theory that the Th1 and Th2 cell ratio shifts towards Th2 dominance during pregnancy may improve fetal survival has gained support from recent studies. Also, the variation in the Th1/Th2 cell ratio is reportedly associated with intrauterine growth retardation and preeclampsia. On the basis of these findings, the analysis of the Th1/Th2 balance may be useful in predicting severe complications during pregnancy. However, simple methods for the analysis of Th1/Th2 balance are presently not available. Recently, it has been reported that regulation of CD26 cell surface expression correlates with the production of Th1-like cytokines. On the other hand, previous studies proposed that the sCD30 molecule is an activation marker useful for evaluation of a Th2 immune response. It is, therefore, possible that the analysis of the Th1/Th2 balance during pregnancy by measuring plasma sCD26 and sCD30 simultaneously is a simple and useful method. We herein demonstrate that combined analysis of sCD26 and sCD30 is a potent surrogate tool to evaluate the Th1/Th2 balance during pregnancy.

A 25-year-old patient with low cardiac risk factors having a combination of variant angina and severe coronary arterial lesions--a case report

A 25-year-old man with low cardiac risks underwent coronary arteriography because of chest pain at rest. His only risk factors for coronary artery disease was smoking. Both right and left coronary arteries were ectatic and the left anterior descending artery was obstructed. In the acetylcholine provocation test, the left circumflex coronary artery showed severe constriction. Thus, this patient was diagnosed as having a combination of variant angina and occlusive coronary artery disease.

Osteochondroma of the pubic symphysis associated with sexual disturbance

Osteochondroma of the pubic symphysis is a rare benign skeletal tumor. We report here a case of an osteochondroma of the pubic symphysis associated with a sexual disturbance, where a computed tomography scan clearly showed a tumor lesion of the pubic symphysis. The case is reported not only because of its rarity but also because it is important that gynecologists should bear this disease in mind, since a patient with this tumor may not visit an orthopedist but a gynecologist.

Primary small cell neuroendocrine carcinoma of the vagina. Marked effect of combination chemotherapy: a case report

Primary small cell neuroendocrine carcinoma of the vagina is extremely rare and very aggressive. Nineteen patients with this cancer have been reported in the English-language literature to date. We report a 51-year-old woman with this cancer. Punch biopsy specimens of the vaginal tumor were studied. Electron microscopy demonstrated neuroendocrine granules in the cytoplasm. Tumor cells were strongly stained for cytokeratin, neuron-specific enolase, chromogranin A and serotonin. These findings were consistent with small cell neuroendocrine carcinoma. The patient was treated with combination chemotherapy. The cancer mass completely disappeared after five cycles of the therapy. The patient is still alive without metastasis 41 months after diagnosis. This is the first report of such a remarkable effect of combination chemotherapy on small cell neuroendocrine carcinoma of the vagina.

Angiosarcoma of the chest wall

A 50-year-old man sustaining bilateral chest wall angiosarcomas at intervals of several months underwent lesion resection. Angiosarcoma is so rare that we found no case in the literature who had undergone bilateral chest wall surgery for such tumors. His second tumor was thought to be metastatic rather than primary. Despite the 2 surgeries, irradiation, and chemotherapy, however, his prognosis was grave, as in other reports on angiosarcoma.

A hypothesis to explain the occurence of inner myometrial laceration causing massive postpartum hemorrhage

BACKGROUND

Inner myometrial lacerations were found in three patients who developed uncontrollable postpartum massive bleeding despite the usual treatment for uterine atony. Because all the patients suffered from hemorrhage shock and their medical status deteriorated, their uteri were surgically removed to stop bleeding. After removal, one of them died. Postpartum hemorrhage was caused by inner myometrial laceration. We hypothesized a cause of inner myometrial laceration, using the three resected uteri, an assumed model of the uterine body, and 34 women.

METHODS

The subjects were 37 women, of whom three were patients with inner myometrial laceration, 23 were women without inner myometrial laceration who underwent cesarean section, and 11 were women in the first stage of labor. The three resected uteri were examined both macroscopically and microscopically. We measured the thickness of the wall of the uterine muscle at the widest point of the uterine corpus and the thickness of the myometrial wall at a transverse section of the uterine cervix, as well as the radius of the inner lumen at the widest point of the uterus in 23 women during cesarean section. We also measured the thickness of the myometrial wall at the widest point of the uterine corpus in 11 women at the end of the first stage of labor during ultrasonic examination. The data were then used to estimate the stress on the uterine muscle.

RESULTS

The stress on the uterine cervix was stronger than that on the uterine corpus during labor. When the stress on the uterine muscle is stronger than a specific value, inner myometrial lacerations develop on the right and/or left side of the uterine cervix. These lacerations may involve large vessels.

CONCLUSIONS

We have discovered another cause of postpartum hemorrhage which we have named inner myometrial laceration. These lacerations appeared to result from a strong stress on the uterine cervix caused by an abnormal rise in intrauterine pressure during labor.

Intracellular lectins associated with N-linked glycoprotein traffic

The vectorial intracellular transport of N-glycan-linked glycoproteins is indispensable for biological functions. In order to sort these glycoproteins to the correct destination, animal intracellular lectins play important roles as sorting receptors. The roles of such lectins in the biosynthetic pathway from the endoplasmic reticulum (ER) to the cell surface are addressed in this review. Calnexin and calreticulin function via specific carbohydrates in quality control of newly synthesized glycoproteins in the ER, and ERGIC-53 seems to function in the transport of glycoproteins from ER to the Golgi complex. In addition to the well-understood role of mannose 6-phosphate receptor in lysosomal protein sorting, the vesicular integral protein of 36 kDa (VIP36) functions as a sorting receptor by recognizing high-mannose type glycans containing alpha1-->2Man residues for transport from Golgi to the cell surface in polarized epithelial cells.

Determination of carbohydrate-deficient transferrin separated by lectin affinity chromatography for detecting chronic alcohol abuse

Carbohydrate-deficient transferrin (CDT) has been established as a valuable biological marker for detecting chronic alcohol abuse. To improve the diagnostic efficiency, we studied new CDT determination procedures involving the use of lectin affinity chromatography with Allomyrina dichotoma agglutinin (allo A) and Trichosanthes japonica agglutinin I (TJA-I) to isolate the CDT isoforms CDT-allo A and CDT-TJA, respectively. These procedures, based on detection of the CDT-allo A and CDT-TJA isoforms in sera, showed high sensitivity (100% and 98%, respectively) and high specificity (93% and 85%, respectively). These results demonstrate that the new procedures involving the use of lectin affinity chromatography are more useful for isolating markers in the CDT test than the conventional charge-based separation method.

Leopard syndrome associated with hyperelastic skin: analysis of collagen metabolism in cultured skin fibroblasts

We present a patient with Leopard syndrome and hyperelastic skin. Biochemical analysis using cultured skin fibroblasts showed normal type III and V collagen synthesis, lysyl hydroxylation level of type I procollagen and processing of pro-alpha(1) and alpha(2)(I). Our results suggest that molecular defects of hyperelasticity in Leopard syndrome are not related to abnormal collagen metabolism, although not all steps of collagen synthesis have been investigated.

Synthesis of conformationally restricted analogs of baclofen, a potent GABAB receptor agonist, by the introduction of a cyclopropane ring

Conformationally restricted analogs of baclofen (2), i.e., 5, 6, and their enantiomers ent-5, and ent-6, the conformations of which were restricted by introducing a cyclopropane ring, were designed as potential GABAB receptor ligands. Reaction of (R)-epichlorohydrin [(R)-7] and (4-chlorophenyl)acetonitrile in the presence of NaNH2 in benzene/tetrahydrofuran gave chiral cyclopropane derivatives 11 and 12, which were then converted into the target compounds 5 and 6, respectively. Their corresponding enantiomers, ent-5 and ent-6, were also synthesized starting from (S)-epichlorohydrin [(S)-7].

Vesicular-integral membrane protein, VIP36, recognizes high-mannose type glycans containing alpha1-->2 mannosyl residues in MDCK cells

The 36 kDa vesicular-integral membrane protein, VIP36, has been originally isolated from MDCK cells as a component of glycolipid-enriched detergent-insoluble complexes containing apical marker proteins, and its luminal domain shows homology to leguminous plant lectins and ERGIC-53. As the first step to identify the functional role of VIP36, the carbohydrate binding specificity of VIP36 was investigated using a fusion protein of glutathione- S -transferase and luminal domain of VIP36 (Vip36). It was found that VIP36 recognizes high-mannose type glycans containing alpha1-->2 Man residues and alpha-amino substituted asparagine. The binding of Vip36 to high-mannose type glycans was independent of Ca(2+)and theoptimal condition was pH 6.0 at 37 degrees C. The concentration at which half inhibition of the binding by Man(7-9).GlcNAc(2). N Ac. Asn occurred was 1.0 x 10(-9)M. The association constant between Man(7-9).GlcNAc(2)in porcine thyroglobulin and immobilized Vip36 was 2.1 x 10(8)M(-1)as determined by means of a biosensor based on surface plasmon resonance. These results indicate that VIP36 functions as an intracellular lectin recognizing glycoproteins which possess high-mannose type glycans, (Manalpha1-->2)(2-4).Man(5). GlcNAc(2).

Ex vivo and in vivo alpha1-adrenoceptor binding characteristics of a novel alpha1L-adrenoceptor antagonist, JTH-601, in rat tissues

In vitro, ex vivo and in vivo alpha1-adrenoceptor binding of JTH-601 (3-[N-[2-(4-hydroxy-2-isopropyl-5-methylphenoxy)ethyl]-N-methylaminometh yl]-4-methoxy-2,5,6-trimethyl-phenol hemifumarate), a novel alpha1L-adrenoceptor antagonist, in rat tissues was investigated. JTH-601 competed in a concentration-dependent manner with [3H]prazosin for binding sites in the prostate, submaxillary gland and spleen of rats in vitro, and the inhibitory effect was not largely different among these tissues, as shown by the Ki values of 2-3 nM. At 0.25, 0.5 and 3 h after oral administration of JTH-601 (6.5 micromol/kg) in rats, there was a significant (57, 64 and 28%, respectively) increase in the apparent dissociation constant (Kd) for prostatic [3H]prazosin binding, compared to the control value. The administration of a higher dose (21.8 micromol/kg) of this agent produced greater (67-99%) increases in Kd values for prostatic [3H]prazosin binding at 0.5-12 h later. Similar significant increases in Kd values, as with the prostate, were seen in the submaxillary gland and heart 0.25-12 h after the oral administration of JTH-601 (6.5 and 21.8 micromol/kg), but significant increases in the spleen and cerebral cortex were seen only at 0.25-3 h and 0.5 h, respectively. At 10 min of i.v. injection of [3H]JTH-601 in rats, in vivo specific binding was observed in the prostate, cerebral cortex, submaxillary gland, spleen and heart but not in the aorta. The binding in the prostate, submaxillary gland and heart, but not in the cerebral cortex and spleen, lasted until 120 min. It is concluded that JTH-601 may exert a considerably sustained blockade of alpha1-adrenoceptors in the prostate of rats. This finding may be important in characterizing the therapeutic effect of JTH-601 for bladder outlet obstruction in patients with benign prostatic hyperplasia.

In vivo measurement by [3H]Tamsulosin of alpha1 adrenoceptors in rat tissues in relation to the pharmacokinetics

The present study was undertaken to simultaneously measure alpha1 adrenoceptors in rat tissues by [3H]tamsulosin in vivo. In vivo specific [3H]tamsulosin binding was observed in the prostate, vas deferens, aorta, submaxillary gland, spleen, heart, lung, and kidney after i.v. injection of the ligand but not in the cerebral cortex and liver. Specific [3H]tamsulosin binding in the kidney, lung, heart, and spleen was greatest at 3 min after i.v. injection and declined rapidly with the disappearance of [3H]tamsulosin from the plasma. On the other hand, [3H]tamsulosin binding in the prostate and aorta peaked at 10 to 60 min after i.v. injection, and a considerable level of specific binding in both tissues persisted up to 240 min. The most sustained binding of [3H]tamsulosin occurred in the submaxillary gland. In vivo specific [3H]tamsulosin binding in rat tissues was effectively inhibited by the coinjection of low doses of unlabeled tamsulosin, prazosin, and terazosin with the radioligand but not by relatively high doses of yohimbine and propranolol. Based on estimated ID50 values, in vivo inhibitory effect of tamsulosin compared with prazosin was 5 to 14 times greater in rat tissues except the spleen, which showed 1.6 times less potent than prazosin. From ratios of ID50 (spleen) to ID50 (submaxillary gland) or ID50 (prostate), tamsulosin was 9 and 19 times, respectively, greater than prazosin in selectivity of alpha1 adrenoceptors in the submaxillary gland and prostate versus the spleen, respectively, suggesting that tamsulosin binds to alpha1A subtype with higher affinity than alpha1B subtype in vivo. The present study suggests that [3H]tamsulosin is a useful radioligand for in vivo measurement of alpha1 adrenoceptors in rat tissues.

Comparative study on pharmacokinetics and in vivo alpha1-adrenoceptor binding of [3H]tamsulosin and [3H]prazosin in rats

The plasma concentration, total radioactivity and in vivo alpha1-adrenoceptor binding in rat tissues after intravenous (i.v.) injection of [3H]tamsulosin were measured and they were compared with those obtained after the injection of [3H]prazosin. The plasma concentration of [3H]tamsulosin was consistently higher than that of [3H]prazosin, with 1.4 times greater areas under the curve (AUC(0-infinity)) of plasma concentration. As there was a significantly lower value of apparent volume of central compartment (Vd(c)) and distribution volume at steady state (Vd(ss)) for [3H]tamsulosin than [3H]prazosin with little difference in elimination rate constant (beta), the higher concentration of [3H]tamsulosin in plasma might be associated mainly with the smaller volume of distribution. The ratio of total radioactivity in tissues to the plasma unbound concentration of [3H]tamsulosin after i.v. injection of the ligand was consistently lower than that of [3H]prazosin. These observations suggest that [3H]tamsulosin is distributed in rat tissues in a more limited manner than [3H]prazosin. A significantly lower level of in vivo specific binding of [3H]tamsulosin than [3H]prazosin was observed in the spleen, heart and liver. Further, the apparent dissociation constant (Kd) and maximal number of binding sites (Bmax) for in vivo specific [3H]tamsulosin binding were considerably lower than those for [3H]prazosin binding. Therefore, these findings suggest that [3H]tamsulosin labels preferentially a subpopulation of the alpha1-adrenoceptor sites in rat tissues labeled by [3H]prazosin. In conclusion, the present study has shown that there is a significant difference in the pharmacokinetics and in vivo alpha1-adrenoceptor binding characteristics between tamsulosin and prazosin.

Ex vivo occupancy by tamsulosin of alpha1-adrenoceptors in rat tissues in relation to the plasma concentration

At 0.5-12 h after oral administration of tamsulosin (2.3 micromol/kg) in rats, there was a significant decrease in specific [3H]prazosin binding in the prostate as compared to the control value. The greater decrease occurred in the submaxillary gland. The effect of tamsulosin was mainly due to a marked reduction of [3H]prazosin binding sites (Bmax) rather than to an increase in the dissociation constant (Kd). In contrast, there was only a slight decrease or no change in the [3H]prazosin binding in the spleen, heart, and cerebral cortex of tamsulosin-administered rats at 0.5-12 h. Oral administration of terazosin (21.7 micromol/kg) significantly increased Kd values for [3H]prazosin binding with little effect on Bmax values in the rat prostate at 3 and 6 h. The greater increases in Kd values were observed in the submaxillary gland, spleen and heart at 0.5-12 h. Terazosin had a slight effect on Kd values for the cerebral cortical [3H]prazosin binding. Tamsulosin was absorbed rapidly after oral administration at a dose of 2.3 micromol/kg in rats, and at 6 h, plasma concentration decreased markedly to approximately one-twentieth of the 0.5 h peak level. alpha1-Adrenoceptor occupancy was estimated as a percentage of decrease in Bmax values for [3H]prazosin binding in tissues of tamsulosin-treated rats compared with control rats. The alpha1-adrenoceptor occupancy by tamsulosin in the prostate and submaxillary gland occurred rapidly in parallel with the rise in plasma concentration of tamsulosin, and lasted for over 12 h despite the marked decrease in plasma concentration. Consequently, it is suggested that tamsulosin produces more selective and sustained occupancy in vivo of alpha1-adrenoceptors in the submaxillary gland and prostate of rats than in other tissues.

The activities of the Tokyo Center

The main World Health Organization (WHO) activities of the Tokyo Center are as follows: (1) It performed the research project entitled 'A Bio-Psycho-Social Study on Children with Emotional and Behavioral Problems' in cooperation with the Beijing and Seoul Centers from 1985 to 1987. These results suggested that the deviant behavior of children in the general population had no biological background, but presumably stemmed from psychosocial disadvantages. (2) It has participated in a field trial for the proposed draft for chapter V of the ICD-10 as the Field Trial Coordinating Center in Japan since 1986 and the first Japanese edition of the ICD-10 Classification of Mental and Behavioral Disorders: Clinical Descriptions and Diagnostic Guidelines were published in 1993. (3) It proposed the collaborative project exploratory eye movements in patients with schizophrenia in 1989 and has promoted the project with the cooperation of six centers that included Beijing, Casablanca, Montreal, Munich, Prague and Sapporo. The findings of the present project indicated that exploratory eye movements may be specific to schizophrenia and can be practically used to discriminate schizophrenia without significantly depending on language.

In vivo receptor binding of novel alpha1-adrenoceptor antagonists for treatment of benign prostatic hyperplasia

New types of alpha1-adrenoceptor antagonists (tamsulosin, KMD-3213 and JTH-601) are currently receiving a great deal of attention, especially in terms of developing effective therapeutic agents to treat bladder outlet obstruction with less side effects, such as postural hypotension, in patients with benign prostatic hyperplasia (BPH). In vivo alpha1-adrenoceptor binding properties of these antagonists in prostate and other tissues of rats were examined. Intravenous injections of tamsulosin, KMD-3213 and JTH-601 inhibited dose-dependently in vivo specific [3H]tamsulosin binding in various tissues. Ratios of ID50(aorta) to ID50(prostate) of KMD-3213 and JTH-601 were greater than those of tamsulosin and prazosin. Further, the ratios of ID50(spleen) to ID50(submaxillary gland) of these drugs were greater than that of prazosin. Following intravenous injections of [3H]KMD-3213 in rats, the amount of specific binding in prostate was significantly greater than that of [3H]prazosin, but that in aorta or spleen was much smaller. Interestingly, [3H]JTH-601 showed little in vivo specific binding in aorta. These data suggest that KMD-3213 and JTH-601 exhibit higher affinity to alpha1-adrenoceptors in prostate and submaxillary gland than in vascular tissues in vivo.

Direct measurement of nitric oxide release in gastric mucosa during ischemia-reperfusion in rats

Nitric oxide (NO) generation in the rat gastric mucosa during ischemia-reperfusion was measured using an NO-sensitive electrode. Under pentobarbital sodium anesthesia, an electrode was inserted into the submucosa from the serous membrane side in the fundus. After steady-state baseline recording, the celiac artery was clamped for 30 min, and then ischemia-reperfusion was achieved by removing the clamp. The clamping of the celiac artery caused a decrease in blood flow and an increase in NO level in the gastric tissue. Just after the removal of the clamp, the NO level rapidly fell and returned to the baseline level. Administration of NG-nitro-L-arginine methyl ester (an NO synthase inhibitor, 30 mg/kg i.p.) before ischemia significantly attenuated both the increase in NO level during ischemia and the formation of acute gastric mucosal lesions observed after 60 min reperfusion. Administration of superoxide dismutase (a superoxide radical scavenger, 10,000 U/kg i.v.) at the end of ischemia inhibited both the rapid decrease in NO level during the reperfusion and the gastric mucosal erosions. Because NO and superoxide radical produce a highly reactive peroxynitrite, it can be argued that NO has an important pathological role in acute gastric mucosal injury induced by ischemia-reperfusion. Our conclusion was strongly supported by immunohistochemical staining of nitrotyrosine residues, an indication of peroxynitrite formation.

[Antiphospholipid antibodies in the elderly patients with ischemic stroke]

The importance of antiphospholipid antibodies as a cause of ischemic stroke in young adults is well demonstrated in the previous studies, but the relationship between the elderly patients with ischemic stroke and antiphospholipid antibodies is not defined. The frequency of positivity for antiphospholipid antibodies was 5.4% (6 out of 112 elderly patients with ischemic stroke), and much higher than that of the elderly healthy individuals (none of 108 individuals) (p < 0.001). Equal numbers of stroke patients with or without antiphospholipid antibodies had other stroke risk factors. The clinical features of the elderly patients with ischemic stroke, who were positive for antiphospholipid antibodies, presented recurrent and multiple infarct dementia, and had thromboses of the other organs. The hemostatic state of the patients with positive antiphospholipid antibodies revealed, in particular, increased intravascular coagulation. Antithrombotic treatment with warfarin at high international normalized ratios (INRs: 1.47-2.80) were effective comparing with antiplatelet treatment with ticlopidine alone in preventing further thromboembolic events.

Abnormality in plasma catecholamines and myocardial adrenoceptors in cardiomyopathic BIO 53.58 Syrian hamsters and improvement by metoprolol treatment

The catecholaminergic neuronal activity and the densities of alpha-1 and beta adrenoceptors and angiotensin II receptors were simultaneously determined in BIO 53.58, a model of idiopathic dilated cardiomyopathy, and F1B control hamsters. Further, we examined the effect of repeated p.o. administration of metoprolol on these biochemical parameters. Compared with F1B control hamsters, there was a significant decrease in Bmax of specific binding of both (-)-[125I]iodocyanopindolol and [3H]prazosin with a marked elevation of plasma catecholamine (mainly norepinephrine and epinephrine) concentrations, in BIO 53.58 hamsters at 11 and 18 weeks of age (severe cardiomyopathic stage), but not at 5 weeks of age. On the other hand, the Bmax value of myocardial [125I]angiotensin II binding in BIO 53.58 hamsters was almost identical to that in F1B hamsters. These results suggest a development of down-regulation of myocardial beta and alpha-1 adrenoceptors because of an increased catecholaminergic neuronal activity with aging in BIO 53.58 hamsters. Repeated p.o. administration of a relatively low dose (1 mg/kg/day) of metoprolol for 7 weeks in 11-week-old BIO 53.58 hamsters caused a significant increase of myocardial (-)-[125I]iodocyanopindolol binding sites with a marked reduction in plasma catecholamine levels; this indicated a significant recovery to the F1B levels. The improvement of these biochemical parameters by metoprolol treatment was also accompanied by a significant decrease in the fibrosis in the heart in BIO 53.58 hamsters. These data suggest that catecholaminergic neurons and adrenoceptors play a part in the development of heart failure in idiopathic dilated cardiomyopathy. Consequently, the present study may provide a further pharmacological basis for the use of beta-1 adrenoceptor antagonists in patients with idiopathic dilated cardiomyopathy.

Lectin-like characteristics of recombinant human interleukin-1beta recognizing glycans of the glycosylphosphatidylinositol anchor

We found that 35S-labeled recombinant human interleukin-1beta (rhIL-1beta) binds phosphatidylinositol-specific phospholipase C-treated human placental alkaline phosphatase, phosphatidylinositol-specific phospholipase C-treated trypanosome surface variant glycoproteins, and urinary uromodulin immobilized on plates or immobilized on CNBr-activated Sepharose 4B. The interaction between rhIL-1beta and these glycoproteins was lectin-like, since it was inhibited in the presence of specific saccharides, i.e. mannose 6-phosphate or synthetic Ac-NH.CH2.CH2. PO4--->6Manalpha1-->(+/-2Manalpha1-->+/-6Manalpha1-->) propyl at about 1 microM. On the other hand, a wide variety of compounds including biantennary sugar chains derived from these glycoproteins as well as ethanolamine phosphate, inositol phosphate, mannose 6-sulfate, mannose 1-phosphate, glucose 6-phosphate, and mannitol 6-phosphate did not show any inhibitory effect at concentrations up to 1 mM. These results indicate that rhIL-1beta interacts with these glycoproteins via the mannose 6-phosphate diester of glycans on the glycosylphosphatidylinositol (GPI) anchor. Furthermore, when monolayers of polarized Madin-Darby canine kidney cells on polycarbonate filter membranes were incubated with 35S-rhIL-1beta in either the apical or basolateral chamber, 35S-interleukin-1beta was found to bind specifically to the apical membranes with a Ka value of 4.6 x 10(7) M-1, and the specific interaction was inhibited by 1 microM mannose 6-phosphate. Since the mannose 6-phosphate diester moiety exists only in the GPI glycans on plasma membranes, it was evident that interleukin-1beta can directly interact with the mannose 6-phosphate diester component of the intact glycan of GPI anchors on plasma membranes.

A partial deficiency of dehydrodolichol reduction is a cause of carbohydrate-deficient glycoprotein syndrome type I

Carbohydrate-deficient glycoprotein (CDG) syndrome type I is a congenital disorder that involves the underglycosylation of N-glycosylated glycoproteins (Yamashita, K., Ideo, H., Ohkura, T., Fukushima, K., Yuasa, I., Ohno, K., and Takeshita, K. (1993) J. Biol. Chem. 268, 5783-5789). In an effort to further elucidate the biochemical basis of CDG syndrome type I in our patients, we investigated the defect in the multi-step pathway for biosynthesis of lipid-linked oligosaccharides (LLO) by the metabolic labeling method using [3H]glucosamine, [3H]mannose, and [3H]mevalonate. The LLO levels in synchronized cultures of fibroblasts from these patients were severalfold lower than those in control fibroblasts in the S phase, and the oligosaccharides released from LLO showed the same structural composition, Glc1 approximately 3.Man9.GlcNAc.GlcNAc, in the case of both the patients and controls. The amount of [3H]mannose incorporated into mannose 6-phosphate, mannose 1-phosphate, and GDP-mannose was greater in fibroblasts from these patients than in the control fibroblasts in the G1 period, although the ratios of these acidic mannose derivatives as indicated by the relative levels of radioactivity were the same for the two types of fibroblasts. Furthermore, upon metabolic labeling with [3H]mevalonate, the level of [3H]dehydrodolichol in fibroblasts from these patients increased in the S phase, and the levels of [3H]dolichol and [3H]dolichol-PP oligosaccharides concomitantly decreased, although the chain length distribution of the respective dolichols and dehydrodolichols was the same in the two types of fibroblasts. These results indicate that the conversion of dehydrodolichol to dolichol is partially defective in our patients and that the resulting loss of dolichol leads directly to underglycosylation.

Synthesis of lipid-linked oligosaccharides is dependent on the cell cycle in rat 3Y1 cells

Synchronized cultures of rat 3Y1 cells, prepared by the density-arrested method, were used to investigate the relationship of N-glycosylation to the cell cycle. Although total cellular proteins were synthesized independently of the cell cycle, the synthesis of membrane-bound proteins was found to be dependent on the cell cycle, the time of maximum synthesis being just before that of maximum DNA synthesis. The synthesis of lipid-linked oligosaccharides (LLO), which are utilized as intermediates in N-glycosylation, increased in the S phase to a level at least ten times higher than in the G1, G2, and M periods. Moreover, the activities of dehydrodolichyl diphosphate synthase and farnesyl diphosphate synthase, which synthesize the precursors of dolichol, also increased in the S phase concomitantly with LLO synthesis. However, since the cell cycle dependency curves of these two enzyme activities were somewhat broader than that of LLO synthesis, the rate-limiting enzyme in the regulation of LLO synthesis might be another one such as dehydrodolichol reductase. These results suggest that LLO synthesis is regulated by multiple synthetic enzymes which are activated in a cell cycle dependent manner.

Detection of proviruses and viral RNA in the early stages of feline immunodeficiency virus infection in cats: a possible model of the early stage of HIV infection

Feline immunodeficiency virus (FIV) infection in cats has been reported to be a useful animal model for human AIDS studies, especially in the early stages of infection. We examined the temporal changes in provirus detection in peripheral blood mononuclear cells (PBMC) and the distribution of FIV-DNA and RNA in feline tissues by the polymerase chain reaction at 10, 35, 70 days after intravenous inoculation of FIV. Viral DNA in the PBMC was detected three to four weeks after infection and its fluctuation was demonstrated for the first time. Ten days after infection, before seroconversion, proviruses were detected only in the mesenteric lymph nodes and intestines. At 35 and 70 days after infection, after seroconversion, proviruses were detected in most lymphoid organs and the salivary glands, but the expression of FIV-RNA was limited to the thymus at 70 days after infection. These results show that FIV-RNA is transcribed from proviral DNA exclusively in the thymus at this stage. We suggest that the quantitative changes in detectable proviruses in the PBMC depend on the relation between the decrease in infected cells caused by cytolytic T lymphocytes and/or apoptosis and their increase caused by the release of a new supply of lymphocytes from the thymus.

Quantitative differences in GlcNAc:beta1-->3 and GlcNAc:beta1-->4 galactosyltransferase activities between human colonic adenocarcinomas and normal colonic mucosa

The activities of GlcNAc:beta1-->3 and GlcNAc:beta1->4 galactosyltransferases in normal human colonic mucosa and well or moderately differentiated colonic adenocarcinomas and their enzyme-kinetic characteristics were investigated. After UDP-[3H]galactose and N-linked type monoantennary oligosaccharides GlcNAc beta1-->2Man alpha1-->3(6)Man beta1-->4GlcNAc) had been incubated with microsome fractions prepared from these tissues, the synthesized [3H]galactose-labeled oligosaccharides were analyzed by Ricinus communis agglutinin-I agarose chromatography, Streptococcus 6646K beta-galactosidase, Gal beta1-->4-specific diplococcal beta-galactosidase, and Gal beta1-->3GlcNAc-specific lacto-N-biosidase digestion. The beta-galactosyltransferases from normal mucosa synthesized both type 1 and type 2 chains at comparable levels, whereas those from adenocarcinomas predominantly synthesized type 2 chains. To our knowledge, this is the first quantitative estimation of GlcNAc:beta1-->3 galactosyltransferase activity toward N-linked sugar chains. Furthermore, we compared the two galactosyltransferase activities in 10 normal mucosa and adenocarcinoma samples and found that while there existed similar levels of GlcNAc:beta1-->4 galactosyltransferase activity in normal mucosa and adenocarcinomas, GlcNAc:beta1-->3 galactosyltransferase activity apparently decreased from 0.67 +/- 0.26 (normal mucosa) to 0.18 +/- 0.11 nmol/min/mg of protein (adenocarcinomas). These results are consistent with those of comparative structural studies on N-linked sugar chains of carcinoembryonic antigen and its normal counterparts and suggest that in the process of differentiated carcinogenesis of human colonic tissues, the expression of GlcNAc:beta1-->3 galactosyltransferase is negatively regulated.

Down-regulation of angiotensin II receptors in hypertrophied human myocardium

1. Specific [125I]-angiotensin II (AngII) binding in normal and hypertrophied human myocardial membranes was saturable and of high affinity. Low concentrations of unlabelled AngII and saralasin competed with [125I]-AngII for the binding sites in these tissues. Thus, saturable [125I]-AngII binding in human myocardium exhibited pharmacological specificity that characterized high affinity receptors for AngII. 2. There was little difference in the apparent dissociation constant (Kd) values for [125I]-AngII binding between normal and hypertrophied human myocardium, whereas the maximal number of binding sites (Bmax) was significantly (51%) lower in the hypertrophied group. Further, PD123177, a selective antagonist of the AT2 receptor subtype, showed three orders of magnitude higher affinity for [125I]-AngII binding sites in both normal and hypertrophied myocardium than losartan, a selective antagonist of the AT1 receptor subtype; the Hill coefficients for these drugs were close to one. 3. A significant decrease in Bmax and Kd values for (-)-[125I]-iodocyanopindolol binding between normal and hypertrophied human myocardium rarely occurred. 4. The present study suggests that both normal and hypertrophied human myocardium predominantly contains the AT2 receptor subtype and that these receptors are down-regulated in hypertrophied tissues.

Alterations in calcium antagonist receptors and calcium content in senescent brain and attenuation by nimodipine and nicardipine

Characteristics of L- and N-type calcium (Ca++) channel antagonist receptors in brains of senescence-accelerated prone mouse (SAMP8) showing age-related deterioration of learning and memory were examined by using (+)-[3H]PN 200-110 and [125I]omega-conotoxin GVIA as radioligands. There was a tendency toward consistent decrease in Bmax for both radioligands in seven brain regions of SAMP8 compared with the control mouse. The reduction in (+)-[3H]Pn 200-110 binding sites was statistically significant in the hippocampus, midbrain and pons/medulla oblongata, and that in [125I]omega-conotoxin binding sites was significant in the cerebral cortex, corpus striatum and pons/medulla oblongata. On the other hand, there was a marked elevation in Ca++ content in the brain of SAMP8. Chronic p.o. administration (0.3, 1 and 3 mg/kg/day for 3 weeks) of nimodipine and nicardipine to SAMP8 caused a significant increase in the Bmax values of (+)-[3H]PN 200-110 binding in the cerebral cortex and hippocampus. This may reflect up-regulation of brain Ca++ channel antagonist receptors as a result of the prolonged blockade by nimodipine and nicardipine. On the other hand, similar administration of amlodipine and nilvadipine failed to produce an enhancement of Bmax values of (+)-[3H]PN 200-110 binding, whereas both drugs at high doses evoked a significant increase in the apparent dissociation constant. Furthermore, the brain Ca++ content in SAMP8 was markedly reduced by chronic p.o. administration of Ca++ channel antagonists, and the decrease was equivalently observed for all of four 1,4-dihydropyridine antagonists in spite of the difference in the effect on brain receptors. In conclusion, the present study suggests that there is an altered Ca++ homeostasis in the SAMP8 brain that is effectively attenuated by chronic administration of nimodipine and nicardipine. Hence SAMP8 may be a suitable animal model for evaluating the therapeutic effects of Ca++ channel antagonists on neurological disorders associated with the aging brain.

A sustained increase in beta-adrenoceptors during long-term therapy with metoprolol and bisoprolol in patients with heart failure from idiopathic dilated cardiomyopathy

Effects of long-term therapy with beta 1-selective antagonists (metoprolol, bisoprolol) on beta-adrenoceptors in lymphocytes of patients with idiopathic dilated cardiomyopathy (DCM) were examined. There was a significant reduction in the number of lymphocyte beta-adrenoceptors in patients with DCM compared to that in healthy volunteers, as demonstrated by a selective decrease in maximum number of binding sites (Bmax) for (-)-[125I]iodocyanopindolol (CYP). A therapy with metoprolol and bisoprolol in these patients caused a marked increase in lymphocyte beta-adrenoceptor density. The significant increase was observed from 2 or 3 months after the start of therapy with these drugs, and it was maintained during the therapy for 24 months. The left ventricular ejection fraction in patients with DCM was improved by the long-term therapy with metoprolol and bisoprolol, and this effect seems to be correlated with an observed enhancement of lymphocyte beta-adrenoceptors in the time course. Also, the increase in lymphocyte beta-adrenoceptors appears to be correlated with a gradual amelioration in circulating catecholamine levels by the long-term therapy with beta-adrenoceptor antagonists in patients with DCM. Thus, the present study suggests that beta-adrenoceptors in lymphocytes of patients with DCM are up-regulated by a long-term therapy with metoprolol and bisoprolol.