Positron emission tomography analysis of [11C]KW-6002 binding to human and rat adenosine A2A receptors in the brain

Adenosine A(2A) receptors are found on striatal neurones projecting to the external pallidum. KW-6002 (istradefylline) is a potent and selective antagonist for the adenosine A(2A) receptors in the CNS and acts to inhibit the excessive activity of this pathway in the MPTP marmoset model of PD, thus relieving parkinsonism. The objectives of this study were to investigate the regional binding of the novel positron emission tomography tracer [(11)C]KW-6002 in the healthy human brain and the rat brain, along with receptor occupancy by cold KW-6002 at varying doses in human. The highest [(11)C]KW-6002 uptake in the rat brain was seen in striatum and lower levels in cortex and cerebellum. Brain [(11)C]KW-6002 uptake was well characterized in humans by a two-tissue compartmental model with a blood volume term, and the ED(50) of cold KW-6002 was 0.5 mg in the striatum. Over 90% receptor occupancy was achieved with daily oral doses of greater than 5 mg. In humans, blockable binding was present in all gray matter structures including the cerebellum, which has not been reported to express A(2A) receptors. MRS 1745, an A(2B) receptor selective antagonist, had no effect on the cerebellar binding of [(11)C]KW-6002 in rats, suggesting that this blockable signal is unlikely to result from an affinity for adenosine A(2B) receptors.

Symptoms of gastroesophageal reflux in diabetes patients

We used a simple questionnaire to determine the presence or absence of symptoms of gastroesophageal reflux disease (GERD) among control (n=531) and diabetic patients (n=629). Of 531 controls, 24.3% reported having symptoms, while 24.9% of 629 diabetic patients had symptoms. Symptomatic diabetic patients (n=157) were then asked to complete a supplemental questionnaire (QUEST) to determine the frequency, severity, and duration of GERD symptoms; a total diagnostic score > or =4 was considered to be positive for GERD. Diabetic patients whose QUEST score was > or =4 had a significantly higher BMI (26.9+/-0.4* vs. 24.4+/-0.4), higher HbA1c (7.5+/-0.2* vs. 7.2+/-0.1), longer duration of diabetes (113.5+/-8.7* vs. 94.0+/-10.6 months), and a higher prevalence of diabetic complications (retinopathy, 24.8%* vs. 21.3%; nephropathy, 32.6%* vs. 19.4%; neuropathy, 30.4%* vs. 23.6%) than diabetic patients whose QUEST score was <4 (*p<0.05). In diabetic patients with GERD, therapy should include not only proton pump inhibitor therapy and other specific measures for GERD, but also appropriate therapy for the diabetes, particularly blood glucose control and weight reduction.

Placental site trophoblastic tumor presenting as subaponeurotic metastasis

Cases of metastatic placental site trophoblastic tumor (PSTT) have a very poor prognosis because these tumors tend to be less sensitive to chemotherapy than other types of gestational trophoblastic disease. We describe the case of a 25-year-old woman who presented with occipital tumor and abnormal vaginal bleeding. Hysterectomy, bilateral salpingo-oophorectomy, and occipital tumor removal revealed a primary PSTT in the uterus, with ovarian and occipital subaponeurotic metastases. She received etoposide, methotrexate, actinomycin-D/cyclophosphamide, vincristine chemotherapy and had a complete clinical remission. Fifteen months later, she had a recurrent subaponeurotic occipital tumor invading the cranium and underwent tumor removal along with cranial bone followed by local irradiation. She was then treated with etoposide, cis-platinum/etoposide, methotrexate, actinomycin-D chemotherapy and again had a remission for 5 months. The patient, however, had a left parietal subaponeurotic tumor, invading the dura mater, and received local irradiation. Soon after, she developed left orbital bone metastasis, treated by local irradiation. These bone metastases responded to the radiation completely. However, multiple organ metastases were found, and she died of the disease. This represents the first case of PSTT with initial subaponeurotic metastasis in a living patient. New modalities of treatment for high-risk or metastatic PSTT need to be developed.

Placental site trophoblastic tumor presenting as subaponeurotic metastasis

Cases of metastatic placental site trophoblastic tumor (PSTT) have a very poor prognosis because these tumors tend to be less sensitive to chemotherapy than other types of gestational trophoblastic disease. We describe the case of a 25-year-old woman who presented with occipital tumor and abnormal vaginal bleeding. Hysterectomy, bilateral salpingo-oophorectomy, and occipital tumor removal revealed a primary PSTT in the uterus, with ovarian and occipital subaponeurotic metastases. She received etoposide, methotrexate, actinomycin-D/cyclophosphamide, vincristine chemotherapy and had a complete clinical remission. Fifteen months later, she had a recurrent subaponeurotic occipital tumor invading the cranium and underwent tumor removal along with cranial bone followed by local irradiation. She was then treated with etoposide, cis-platinum/etoposide, methotrexate, actinomycin-D chemotherapy and again had a remission for 5 months. The patient, however, had a left parietal subaponeurotic tumor, invading the dura mater, and received local irradiation. Soon after, she developed left orbital bone metastasis, treated by local irradiation. These bone metastases responded to the radiation completely. However, multiple organ metastases were found, and she died of the disease. This represents the first case of PSTT with initial subaponeurotic metastasis in a living patient. New modalities of treatment for high-risk or metastatic PSTT need to be developed

Adenosine A2A receptor-mediated modulation of GABA and glutamate release in the output regions of the basal ganglia in a rodent model of Parkinson's disease

A target neuron of adenosine A(2A) receptor antagonists to exert anti-parkinsonian activities has been currently identified to be, at least in part, striatopallidal medium spiny neurons (MSNs). In the present study, we determine whether A(2A) receptor-mediated modulation is associated with changes in the release of GABA and glutamate in the substantia nigra pars reticulata (SNr), an output structure of the whole basal ganglia network, using in vivo microdialysis in a rat Parkinson's disease (PD) model. In 6-hydroxydopamine (OHDA)-lesioned rats compared with normal rats, basal extracellular GABA levels in the SNr show no change, whereas basal glutamate levels are significantly increased. Oral administration of the A(2A) receptor-selective antagonist (E-1,3-diethyl-8-(3,4-dimethoxystyryl)-7-methyl-3,7-dihydro-1-H-purine-2,6-dion (KW-6002) to 6-OHDA-lesioned rats at 1 mg/kg caused a marked and sustained increase of GABA and glutamate levels in the SNr. The increase of nigral glutamate by KW-6002 was abolished by a kainic acid-induced lesion of the globus pallidus (GP) or subthalamic nucleus (STN) in 6-OHDA-lesioned rats, whereas the increase of nigral GABA was completely blocked by the GP-lesion but only partially blocked by the STN-lesion. These results indicate that changes in neurotransmitter release in the SNr brought about by KW-6002 are largely attributable to blockade of A(2A) receptor-mediated modulation of striatopallidal MSNs. Thus, these actions of KW-6002 on striatopallidal MSNs may be the main mechanism for ameliorating PD by A(2A) antagonists.

Low risk endometrial cancer: A study of pelvic lymph node metastasis

The aim of our study was to find preoperative or intraoperative pathologic indicators that would discriminate a subgroup of early corpus cancers that would not require lymphadenectomy. A retrospective review of the medical records of 107 patients with endometrioid adenocarcinoma, FIGO grade 1 or 2 tumor, myometrial invasion ≤50%, and no intraoperative evidence of macroscopic extrauterine spread was performed. Clinicopathologic risk factors were analyzed with Fisher ′s exact test with regards to pelvic lymph node metastasis. The median age of the patients was 54 years. Pelvic lymph node metastasis was observed in five of 107 patients (4.7%), where two patients with small tumors of 2 cm or less had positive pelvic lymph nodes. The presence of positive pelvic lymph nodes did not correlate with depth of invasion, histologic grade, cervical invasion, peritoneal cytology, menopausal status, preoperative serum CA125 level, or primary tumor diameter. Only lymphvascular space involvement (P < 0.0001) was significantly correlated to pelvic lymph node metastasis. We suggest that all patients with endometrial cancer who are taken to the operating room for primary therapy should be prepared to undergo extended surgical staging, except when clinical or operative factors increase patients' morbidity.

Low risk endometrial cancer: a study of pelvic lymph node metastasis

The aim of our study was to find preoperative or intraoperative pathologic indicators that would discriminate a subgroup of early corpus cancers that would not require lymphadenectomy. A retrospective review of the medical records of 107 patients with endometrioid adenocarcinoma, FIGO grade 1 or 2 tumor, myometrial invasion <or=50%, and no intraoperative evidence of macroscopic extrauterine spread was performed. Clinicopathologic risk factors were analyzed with Fisher 's exact test with regards to pelvic lymph node metastasis. The median age of the patients was 54 years. Pelvic lymph node metastasis was observed in five of 107 patients (4.7%), where two patients with small tumors of 2 cm or less had positive pelvic lymph nodes. The presence of positive pelvic lymph nodes did not correlate with depth of invasion, histologic grade, cervical invasion, peritoneal cytology, menopausal status, preoperative serum CA125 level, or primary tumor diameter. Only lymphvascular space involvement (P < 0.0001) was significantly correlated to pelvic lymph node metastasis. We suggest that all patients with endometrial cancer who are taken to the operating room for primary therapy should be prepared to undergo extended surgical staging, except when clinical or operative factors increase patients' morbidity.

Docetaxel in combination with carboplatin for chemo-naive patients with epithelial ovarian cancer

We conducted a study of docetaxel-carboplatin combination therapy to confirm the efficacy and toxicity in chemotherapy-naive patients with ovarian cancer. Docetaxel 70 mg/m2 and carboplatin (area under the concentration-vs.-time curve of 5) were administered consecutively on day 1 of a 21-day cycle for five planned cycles in chemo-naive patients with the International Federation of Gynecology and Obstetrics stage IC to IV ovarian cancer with or without successful cytoreductive surgery at staging laparotomy. Twenty-six patients (median age, 53 years; range, 34-76 years) were enrolled into this trial at Niigata University Hospital. The major toxicity with this regimen was neutropenia. The incidence of grade 3 and 4 neutropenia were 27% (7/26) and 69% (18/26), respectively. However, the neutropenia was brief and reversible with G-CSF support. Nausea/emesis, fatigue, arthralgia/myalgias, and alopecia were the most common nonhematologic toxicities, in which no grade 3 or 4 toxicity was observed. Neurotoxicity was infrequently observed. Nine of 11 assessable patients responded to the regimen. We conclude that the combination of carboplatin and docetaxel seems to be highly active in ovarian cancer with the major toxicity of neutropenia, and the extremely low incidence of clinically significant neurotoxicity. Randomized controlled clinical trials should be conducted to define a role for this regimen in ovarian cancer.

Activation of a K-252b-Sensitive Protein Kinase is Necessary for a Post-Synaptic Phase of Long-Term Potentiation in Area CA1 of Rat Hippocampus

K-252b, a potent inhibitor of protein kinases blocked a late phase of long-term potentiation (LTP) in area CA1 of rat hippocampal slices, resulting in decremental LTP. It also prevented the slowly developing increase in sensitivity of CA1 neurons to iontophoretically administered alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) which was seen in control slices that exhibit nondecremental LTP. However, K-252b applied 60 - 180 min after the induction of LTP had no effect on the potentiated synaptic and AMPA-induced responses. A K-252b-sensitive protein kinase may therefore be involved in a slowly developing postsynaptic component of LTP.

Prognostic factors and failure pattern in lymph node-negative stage IB and II cervical carcinoma treated with radical hysterectomy and postoperative irradiation

The aim was to determine the prognostic factors and recurrence pattern in stages IB and II cervical carcinoma patients with negative pelvic lymph nodes. 224 patients with stages IB and II cervical carcinoma underwent radical hysterectomy (RH) from 1982 through 1995. Of 161 patients with negative lymph nodes, 65 patients received postoperative irradiation (RT) and 96 patients were given no further therapy according to surgical pathological findings. The overall 5-year disease-free survival was 94.1%. Two of 96 RH patients (2%) and 10 of 65 RH + RT patients (15%) had recurrence in pelvic and distant sites almost equally. Multivariate analysis revealed deep cervical invasion as the only independent prognostic factor. The 5-year disease-free survival was 98.8% for patients with shallow invasion and 85.8% for patients with deep invasion (p < 0.0001). It is worthwhile to develop new strategies for the lymph node-negative patients with deep stromal invasion.

MR imaging underestimates stromal invasion in patients with adenocarcinoma of the uterine cervix

PURPOSE OF INVESTIGATION

To evaluate magnetic resonance (MR) imaging in assessing the depth of stromal invasion in patients with adenocarcinoma of the uterine cervix.

METHODS

Twenty-three women with adenocarcinoma of the cervix underwent T2-weighted and dynamic MR imaging before surgical evaluation. The images were evaluated for the depth of stromal invasion and compared with histological results.

RESULTS

Twelve of 23 patients (52%) were correctly diagnosed in agreement with the histological findings. However, the depth of stromal invasion was underestimated in ten patients (44%). In four of nine patients who exhibited scattered type lesions, no lesions were detected by MR imaging, although deep stromal invasion (more than 1/3) was recognized histologically. In contrast, all 11 patients showed cancer lesions in solid type adenocarcinomas with deep stromal invasion.

CONCLUSION

MR imaging detected less stromal invasive lesions in adenocarcinoma of the cervix than surgical specimens, and some scattered type adenocarcinomas could not be visualized.

Docetaxel in combination with carboplatin for chemo-naive patients with epithelial ovarian cancer

We conducted a study of docetaxel-carboplatin combination therapy to confirm the efficacy and toxicity in chemotherapy-naive patients with ovarian cancer. Docetaxel 70 mg/m2 and carboplatin (area under the concentration-vs.-time curve of 5) were administered consecutively on day 1 of a 21-day cycle for five planned cycles in chemo-naive patients with the International Federation of Gynecology and Obstetrics stage IC to IV ovarian cancer with or without successful cytoreductive surgery at staging laparotomy. Twenty-six patients (median age, 53 years; range, 34–76 years) were enrolled into this trial at Niigata University Hospital. The major toxicity with this regimen was neutropenia. The incidence of grade 3 and 4 neutropenia were 27% (7/26) and 69% (18/26), respectively. However, the neutropenia was brief and reversible with G-CSF support. Nausea/emesis, fatigue, arthralgia/myalgias, and alopecia were the most common nonhematologic toxicities, in which no grade 3 or 4 toxicity was observed. Neurotoxicity was infrequently observed. Nine of 11 assessable patients responded to the regimen. We conclude that the combination of carboplatin and docetaxel seems to be highly active in ovarian cancer with the major toxicity of neutropenia, and the extremely low incidence of clinically significant neurotoxicity. Randomized controlled clinical trials should be conducted to define a role for this regimen in ovarian cancer.

Evaluation of [4-O-methyl-(11)C]KW-6002 as a potential PET ligand for mapping central adenosine A(2A) receptors in rats

KW-6002, a xanthine-based adenosine A(2A) antagonist, was labelled with the positron emitter carbon-11 by O-methylation of its precursor, KF23325, using [(11)C]iodomethane and was evaluated in rats as a putative in vivo radioligand for positron emission tomography (PET). Following intravenous injection of [(11)C]KW-6002, radioactivity was measured in blood, plasma, peripheral tissues, and in discrete brain tissues over a 2-h time period commensurate with PET scanning. In brain, [(11)C]KW-6002 showed highest retention in striata, with evidence of saturable binding, and lowest retention in frontal cortex (a tissue low in adenosine A(2A) receptors). PET scanning with [(11)C]KW-6002 demonstrated a specific signal in the striata which could be described using compartmental modelling. Specific binding was, however, also detected in extrastriatal regions, including brain areas reported to have low adenosine A(2A) receptor density. Blocking studies with the A(1) selective antagonist KF15372 and the non xanthine-type A(2A) antagonist ZM 241385 failed to elucidate the nature of this binding. Thus, although [(11)C]KW-6002 shows some potential for development as a PET ligand for quantifying striatal adenosine A(2A) receptor function, its in vivo selectivity requires further investigation.

Neoadjuvant chemotherapy for patients younger than 50 years with high-risk squamous cell carcinoma of the cervix

OBJECTIVE

To evaluate the response rate and toxicity and to improve survival, neoadjuvant chemotherapy (NAC) was utilized in patients younger than 50 years with locally advanced cervical squamous cell carcinoma.

METHODS

Twenty-one patients were treated with preoperative NAC. Eligibility included patients with previously untreated stage IB or IIA with deep stromal invasion assessed by magnetic resonance imaging or bulky tumor or IIB squamous cell carcinoma who were younger than 50 years. The NAC consisted of cisplatin (60 mg/m(2)) on day 1, vinblastine (4 mg/m(2)/day) on days 1 and 2, and peplomycin (10 mg/day) on days 1, 8, and 15 (PVP). Treatment was repeated every 3 weeks for a total of two cycles. All 21 patients underwent radical hysterectomy following NAC. Postoperative radiotherapy was given to 18 patients. We used 21 patients who underwent radical hysterectomy and postoperative radiation therapy as a nonrandomized control group.

RESULTS

The response rate for NAC was 86% (18/21). Two patients required discontinuation of PVP treatment after one administration because of grade 4 neutropenia and thrombocytopenia, and decreased carbon monoxide diffusion capacity, respectively. In the NAC group, stromal invasion was significantly reduced (P = 0.0103), and the incidence of lymph node metastasis was decreased. No patients had positive parametrial and vaginal margins. The overall 5-year survival rate was 84.0% in the NAC group, which was significantly better than that in the control group (58.9%) (P = 0.0434).

CONCLUSIONS

NAC for younger patients with locally advanced cervical carcinoma is thought to be safe, well tolerated, effective, and useful for increasing operability, decreasing pathological risk factors, and improving survival.

Stage III endometrial cancer: analysis of prognostic factors and failure patterns after adjuvant chemotherapy

OBJECTIVE

This study was performed to assess the prognostic factors and patterns of recurrence in stage III endometrial carcinoma treated with surgery and adjuvant chemotherapy.

METHODS

A retrospective review of 61 stage III endometrial carcinoma patients treated between 1988 and 1998 at Niigata University Hospital was performed. All patients underwent surgery, followed by adjuvant chemotherapy consisting of intravenous cisplatin, doxorubicin, and cyclophosphamide. Multivariate analysis was performed for the prognostic factors and actuarial techniques were used for the survival and recurrence rates.

RESULTS

The 5-year disease-free survival was 78.6%. Multivariate analysis revealed deep myometrial invasion and lymph-vascular space involvement correlated significantly with disease-free survival. Based on these two factors, the patients could be divided into low-risk and high-risk groups. The 5-year disease-free survival for the low-risk group was 100%, which was significantly better than the 59.1% for the high-risk group. Disease recurrence occurred in 13 of 30 high-risk patients, and there was no recurrence in the 31 low-risk patients. Looking at the patterns of recurrence for the high-risk group by lymph node metastasis, 5 recurrences were locoregional, 1 was locoregional/distant, and 1 was distant in 16 node-positive high-risk patients. In 14 node-negative patients, 5 had distant and 1 had locoregional/distant recurrences.

CONCLUSIONS

The locoregional failure in the node-positive high-risk group deserves further attention. For improvement of locoregional control, it may be worthwhile to consider new strategies. The role of new adjuvant chemotherapy should be investigated to control distant failure in node-negative high-risk patients.

New aspects of physiological and pathophysiological functions of adenosine A2A receptor in basal ganglia

There is now growing interest in the functional role of adenosine A2A receptors. Their distribution within the brain is restricted in the basal ganglia, particularly abundant in the striatum, which are thought to play a crucial role in the control of motor behavior. Indeed, newly developed A2A receptor selective antagonists have a profound influence on motor functions, with anti-Parkinsonian activities in several animal models. Striatal spiny neurons serve as a major anatomical locus for the relay of cortical information flow through the basal ganglia. The GABA releasing projection neurons represent the A2A receptor-mediated main target of adenosine. The GABAergic synaptic neurotransmission is regulated by adenosine via A2A receptors on the presynaptic terminals. Blockade of this modulatory function by A2A antagonists could repair striatopallidal abnormal neuronal activities provoked by striatal dopamine depletion in the Parkinsonian state. A2A receptor antagonists provide a novel therapeutic potential for the treatment of Parkinson's disease.

Adenosine A(2A) receptor enhances GABA(A)-mediated IPSCs in the rat globus pallidus

1. The actions of adenosine A(2A) receptor agonists were examined on GABAergic synaptic transmission in the globus pallidus (GP) in rat brain slices using whole-cell patch-clamp recording. GP neurones were characterized into two major groups, type I and type II, according to the degree of time-dependent hyperpolarization-activated inward rectification and the size of input resistance. 2. The A(2A) receptor agonist 2-[p-(2-carboxyethyl)phenethylamino]-5'-N-ethylcarboxamido- adenosine (CGS21680; 0.3-3 microM) enhanced IPSCs evoked by stimulation within the GP. The actions of CGS21680 were blocked by the A(2A) antagonists (E)-8-(3,4-dimethoxystyryl)-1,3-dipropyl-7-methylxanthine (KF17837) and 4-(2-[7-amino-2-(2-furyl)[1,2,4]triazolo[2,3-a][1,3,5]triazin-5-ylamino]ethyl)phenol (ZM241385). 3. The CGS21680-induced increase in IPSCs was associated with a reduction in paired-pulse facilitation. CGS21680 (0.3 microM) increased the frequency of miniature IPSCs (mIPSCs) without affecting mIPSC amplitude. These observations demonstrated that the enhancement of IPSCs in the GP was attributable to presynaptic, but not postsynaptic, A(2A) receptors. 4. The results suggest that A(2A) receptors in the GP serve to inhibit GP neuronal activity, thereby disinhibiting subthalamic nucleus neurone activity. Thus, the A(2A) receptor-mediated presynaptic regulation in the GP, together with the A(2A) receptor-mediated intrastriatal presynaptic control of GABAergic neurotransmission described previously, may play a crucial role in controlling the neuronal functions of basal ganglia. This A(2A) receptor-mediated presynaptic dual control in the striatopallidal pathway could also afford the mode of action of A(2A) antagonists for ameliorating the symptoms of Parkinson's disease in an animal model.

Systemic administration of adenosine A(2A) receptor antagonist reverses increased GABA release in the globus pallidus of unilateral 6-hydroxydopamine-lesioned rats: a microdialysis study

The ability of adenosine A(2A) receptor antagonists to exhibit antiparkinsonian activity has recently been reported, but the mechanisms of action are still unknown. Since A(2A) receptors have been localized to GABAergic striatopallidal neurons, it is probable that these antagonists affect the activity of these neurons. In the present study, extracellular GABA basal levels were increased in the ipsilateral striatum and globus pallidus following a unilateral 6-hydroxydopamine lesion of the nigrostriatal pathway. The A(2A) receptor-selective antagonist KW-6002 (3mg/kg, p.o.) caused a marked and sustained decrease of extracellular GABA levels in the globus pallidus of the 6-hydroxydopamine-lesioned rats, whereas no changes in GABA levels were observed in the globus pallidus of the non-lesioned rats. Microinjection of the A(2A) receptor agonist CGS21680 (0.005-0.5 microg) into the striatum of non-lesioned animals increased GABA concentrations in the globus pallidus, which was abolished by the voltage-dependent Na(+) channel blocker tetrodotoxin (1 micromol/l) delivered locally to the globus pallidus via the dialysis membrane. Furthermore, intrapallidal infusion of CGS21680 (10 micromol/l) also increased GABA levels in the globus pallidus. These data indicate that GABA release from striatopallidal neurons is regulated through A(2A) receptors in both the striatum and globus pallidus. The reversal of the 6-hydroxydopamine-induced increase in pallidal GABA levels by KW-6002 suggests that the antiparkinsonian effects of A(2A) receptor antagonists occur on the striatopallidal neurons.

[A case of stage IV gastric cancer responding to combined chemotherapy by intravenous, intraarterial and intraperitoneal injection]

We treated a case of unresectable gastric cancer in which peritoneal lavage cytology and the primary tumor responded to combined chemotherapy by intravenous, intraarterial and intraperitoneal injection. The patient was a 61-year-old male with loss of appetite. He underwent laparotomy for gastric cancer in November, 1997. An intraperitoneal catheter was set without gastrectomy because of the unresectability due to extensive peritoneal dissemination and local invasion to pancreas. The patient was given combined chemotherapy using 5-FU 6,000 mg i.v., CDDP 360 mg i.p. and 5-FU 10,500 mg ia by the catheters in the supra vena cava, right gastroepiploic artery and peritoneal cavity. One month after laparotomy, peritoneal lavage cytology had changed to class I from class V, and the primary tumor had been reduced to 10 mm in size from a diffusely infiltrating tumor. His quality of life in appetite and activity was improved for 13 months.

Palmar fasciitis and polyarthritis associated with squamous cell carcinoma of the cervix

Palmar fasciitis and polyarthritis (PFPA) is an uncommon syndrome characterized by progressive and extensive rheumatic disease. We present the first example of PFPA in association with squamous cell carcinoma of the uterine cervix and peritoneal carcinoma. A 54-year-old woman developed pain in both shoulders and flexion deformities of all fingers in both hands due to an increasing swelling of both palms. She underwent surgery and histologic examination of the removed uterus revealed squamous cell carcinoma, nonkeratinizing type with a small portion of undifferentiated carcinoma. Chemotherapy resulted in an excellent response, during which the arthritic symptoms improved gradually. PFPA can occur in a wide range of cancers and warrants extensive investigation for a malignant tumor.

Failure of high-dose chemotherapy with peripheral blood stem cell support for refractory placental site trophoblastic tumor

Placental site trophoblastic tumor (PSTT) is a rare form of gestational trophoblastic disease. The metastatic and refractory cases have a very poor prognosis. To our knowledge, this is the first report of the application of high-dose chemotherapy with autologous peripheral blood stem cell transplantation (PBSCT) for the treatment of refractory metastatic PSTT. A 36-year-old woman had a metastatic PSTT refractory to several lines of chemotherapy. She was treated with high dose of carboplatin and etoposide with autologous PBSCT. She showed only a temporary response to high-dose chemotherapy with PBSCT support and died of disease.

Rescue of locomotor impairment in dopamine D2 receptor-deficient mice by an adenosine A2A receptor antagonist

In Parkinson's disease a degeneration of dopaminergic neurons of the nigrostriatal pathway is observed. Loss of dopaminergic regulation of striatal neuron activity results in altered motor functions. Adenosine A2A (A2AR) and dopamine D2 (D2R) receptors are colocalized in striatal medium spiny neurons. It has been proposed that adenosine binding to A2AR lowers the affinity of dopamine for D2R, thus modulating the function of this receptor. Absence of D2R in knockout mice (D2R-/-) results in impaired locomotion and coordinated movements. This indicates that absence of dopamine in Parkinson's disease might principally affect D2R-mediated effects with regard to locomotor functions. A2AR-selective antagonists have been demonstrated to have anti- parkinsonian activities in various models of Parkinson's disease in rodents and nonhuman primates. In this article, D2R-/- mice were used to explore the possibility that an A2AR antagonist might reestablish their motor impairment. Interestingly, blockade of A2AR rescues the behavioral parameters altered in D2R-/- mice. In addition, the level of expression of enkephalin and substance P, which were altered in D2R-/-, were also reestablished to normal levels after A2AR antagonist treatment. These results show that A2AR and D2R have antagonistic and independent activities in controlling neuronal and motor functions in the basal ganglia. They also provide evidence that selective A2AR antagonists can exhibit their anti-parkinsonian activities through a nondopaminergic mechanism.

Combined use of the adenosine A(2A) antagonist KW-6002 with L-DOPA or with selective D1 or D2 dopamine agonists increases antiparkinsonian activity but not dyskinesia in MPTP-treated monkeys

The novel selective adenosine A(2A) receptor antagonist KW-6002 improves motor disability in MPTP-treated parkinsonian marmosets without provoking dyskinesia. In this study we have investigated whether KW-6002 in combination with l-DOPA or selective D1 or D2 dopamine receptor agonists enhances antiparkinsonian activity in MPTP-treated common marmosets. Combination of KW-6002 with the selective dopamine D2 receptor agonist quinpirole or the D1 receptor agonist SKF80723 produced an additive improvement in motor disability. Coadministration of KW-6002 with a low dose of L-DOPA also produced an additive improvement in motor disability, and increased locomotor activity. The ability of KW-6002 to enhance antiparkinsonian activity was more marked with L-DOPA and quinpirole than with the D1 agonist. However, despite producing an enhanced antiparkinsonian response KW-6002 did not exacerbate L-DOPA-induced dyskinesia in MPTP-treated common marmosets previously primed to exhibit dyskinesia by prior exposure to L-DOPA. Selective adenosine A(2A) receptor antagonists, such as KW-6002, may be one means of reducing the dosage of L-DOPA used in treating Parkinson's disease and are potentially a novel approach to treating the illness both as monotherapy and in combination with dopaminergic drugs.

Synthesis of tricyclic compounds as steroid 5alpha-reductase inhibitors

A series of 4-phenoxybutyric acid derivatives attached to a tricyclic skeleton were prepared and evaluated as 5alpha-reductase inhibitors. Structure activity relationships for these compounds in terms of rat epididymis (type 2) 5alpha-reductase inhibitory activities reveal that 1) the substitution pattern at the 11-position of dibenz[b,e]oxepin influenced potency, 2) higher lipophilicity of the tricyclic skeleton improved potency, whereas the existence of a basic nitrogen atom in this skeleton was detrimental to potency, and 3) isobutyl substitution at the 8 positon of the azepine skeleton was tolerated. Among the tricyclic compounds studied, 4-[3-[5-benzyl-8-(2-methyl)propyl-10,11-dihydrodibenz[b,f]azepine- 2-carboxamido]phenoxy]butyric acid (26) was the most potent inhibitor of rat type 2 5alpha-reductase at 0.1 microM.

Ovarian metastasis in stage IB and II cervical adenocarcinoma

We performed the present study to identify those patients with adenocarcinoma of the cervix in whom ovarian preservation might be acceptable. Between January 1971 and December 1996, 82 patients with International Federation of Gynecology and Obstetrics stage IB and II cervical adenocarcinoma and adenosquamous carcinoma, treated by radical hysterectomy, bilateral salpingo-oophorectomy, and pelvic node dissection, were identified. The mean age of the patients was 44.6 years (range 27-72). The incidence of ovarian metastasis was more frequent in stage II (19.0%) than in stage IB disease (2.5%), in which only 1 patient with apparent extrauterine disease at laparotomy had an ovarian metastasis. No patients with up to inner two-thirds of stromal invasion had ovarian metastasis; however, 5 of 24 patients with outer one-third stromal invasion (20.8%) and 4 of 20 with parametrial invasion (20.0%) had ovarian metastasis. A significantly higher incidence of ovarian metastasis was also observed in 5 of 20 cases with lymph node metastasis (25.0%) than in 4 of 62 patients without lymph node metastasis (6.5%). Multivariate analysis, however, found only deep stromal invasion to be an independent risk factor for ovarian metastasis. Although it would be reasonable to conserve normal-appearing ovaries in young women undergoing radical hysterectomy for treatment of stage IB cervical adenocarcinoma and adenosquamous carcinoma, gross intraoperative inspection of the radical hysterectomy specimen may identify deep cervical invasion or extrauterine spread in those who are at increased risk of ovarian metastases.

Observations of high iron diamine-alcian blue stain in uterine cervical glandular lesions

We studied epithelial glycoproteins in uterine cervical lesions, including glandular lesions, and investigated whether a more accurate diagnosis could be obtained using high iron diamine-alcian blue (HID-AB) stain and immunostaining with carcinoembryonic antigen (CEA). In addition, we examined the usefulness of preoperative diagnosis using biopsy specimens stained with HID-AB and CEA. Normal endocervical glands showed a predominance of sulfomucin, while adenocarcinoma predominantly showed sialomucin. CEA was highly detected in adenocarcinoma, but not in normal endocervix or in glandular dysplasia, suggesting that this stain has high specificity. The staining patterns of biopsy specimens and hysterectomy specimens were similar. Therefore HID-AB stain and CEA stain may be useful as a supplementary means of diagnosing uterine cervical lesions.

Antiparkinsonian effect of a new selective adenosine A2A receptor antagonist in MPTP-treated monkeys

BACKGROUND

Chronic treatment with L-3,4-dihydroxyphenylalanine (L-dopa) is often associated with motor side effects in PD patients. The search for new therapeutic approaches has led to study the role of other neuromodulators including adenosine. Among the four adenosine receptors characterized so far, the A2A subtype is distinctively present on striatopallidal output neurons containing enkephalin and mainly bearing dopamine (DA) D2 receptors (indirect pathway). Studies in DA-denervated rats suggest that blockade of adenosine A2A receptors might be used in PD.

OBJECTIVE

To evaluate the antiparkinsonian effect of a new selective adenosine A2A receptor antagonist, KW-6002, in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated monkeys.

METHODS

In the present study, we used six MPTP-exposed cynomolgus monkeys already primed and exhibiting L-dopa-induced dyskinesias to evaluate both the antiparkinsonian and dyskinetic effect upon challenge with two oral doses (60 and 90 mg/kg) of KW-6002 administered alone or in combination with L-dopa/benserazide (50/12.5 mg).

RESULTS

KW-6002 administered alone produced a dose-dependent antiparkinsonian response that reached the level of efficacy of L-dopa/benserazide but was less likely to reproduce dyskinesias in these animals. When co-administered, KW-6002 potentiated the effects of L-dopa/benserazide on motor activity (up to 30%) without affecting the dyskinetic response.

CONCLUSION

Adenosine A2A receptor antagonists have antiparkinsonian effects of their own with a reduced propensity to elicit dyskinesias. They might therefore be useful agents in the treatment of PD.

Glutathione S-transferase pi immunostaining of cisplatin-resistant ovarian cancer cells in ascites

OBJECTIVE

To clarify immunohistochemically the correlation between glutathione S-transferase pi (GST pi) expression of surgically resected specimens and clinical response in ovarian cancer and to evaluate ascites cytology using GST pi staining.

STUDY DESIGN

Eighty-seven patients with ovarian cancer underwent initial debulking surgery and received cisplatin-based chemotherapy after surgery. Immunostaining for GST pi was performed on formalin-fixed sections of the patients' tumors. The cytologic slides of 24 cases were acquired for evaluation of GST pi staining.

RESULTS

Of 87 surgically resected specimens, 55 (63.2%) were GST pi positive. Twenty-five of 28 patients (89.3%) who showed no response to chemotherapy had GST pi-positive tumor cells. The predictive value of positive GST pi staining for drug resistance was 75.8% (25/33). Of 18 cases that were GST pi positive in surgically resected specimens, 17 were positive in ascites cytology. Five cases were negative in both resected specimens and ascites cytology. There was a significant correlation in the GST pi labelling index between resected specimen and ascites cytology from the same case; the correlation coefficient was .701 and P value < .001.

CONCLUSION

Overexpression of GST pi is related to resistance to cisplatin, and GST pi staining of ascites cytology can be used in pretherapeutic assessment of patients with ovarian cancer.

[Reevaluation and potential therapeutic effects of estrogen therapy to prostate cancer patients]

Survival time of 65 patients with stage D2 prostate cancer who were treated by estrogen with or without antiplatelet drugs was examined. Survival time of 37 patients with antiplatelet drugs was significantly longer than that of 28 histological control ones. The frequency of death of cardiovascular disease in the former group decreased to 5.3%. Next, progression free time of the 37 patients was compared to the time of 37 patients treated by antiandrogen therapy. The former one was better than the latter. However, survival time after relapse of the estrogen group was shorter than the control. These results suggest that estrogen therapy improved by a combination of antiplatelet drugs has to be reevaluated and contains specific therapeutic effects differing from antiandrogen therapy.

Adenosine A2A antagonist: a novel antiparkinsonian agent that does not provoke dyskinesia in parkinsonian monkeys

Treatment of Parkinson's disease with L-dopa therapy leads to long-term complications, including loss of drug efficacy and the onset of dyskinesia. Adenosine A2A receptors in striatum are selectively localized to GABAergic output neurons of the striato-pallidal pathway and may avoid such problems. The novel adenosine A2A receptor antagonist KW-6002 has been examined for antiparkinsonian activity in MPTP-treated primates. Oral administration of KW-6002 reversed motor disability in MPTP-treated common marmosets in a dose-dependent manner. However, KW-6002 only modestly increased overall locomotor activity and did not cause abnormal movement, such as stereotypy. The ability of KW-6002 to reverse motor disability was maintained on repeated daily administration for 21 days, and no tolerance was observed. KW-6002 induced little or no dyskinesia in MPTP-treated primates previously primed to exhibit dyskinesia by prior exposure to L-dopa. These results suggest that selective adenosine A2A receptor antagonists represent a new class of antiparkinsonian agents that improve disability without producing hyperactivity and without inducing dyskinesia.

Unique binding pocket for KW-4679 in the histamine H1 receptor

The histamine H1 receptor has an aspartate (Asp) residue in transmembrane helix 3 (TM3), which is well-conserved among biogenic amine receptors. The Asp residue is one of the most crucial amino acids for ligand binding. The tested histamine H1 receptor antagonists with tri- and tetracyclic structures were not selective for histamine H1 receptors and showed affinity for several other biogenic amine receptors. In contrast, KW-4679 ((Z)-11-[3-(dimethylamino)propylidene]-6,11-dihydrodibenz[b, e]oxepin-2-acetic acid hydrochloride), a tricyclic compound, was a selective histamine H1 receptor antagonist. [3H]KW-4679 had high affinity (Kd value of 2.5 +/- 0.12 nM) for wild-type human histamine H1 receptors. In the [3H]KW-4679 binding assay, replacement of Asp107 by alanine by site-directed mutagenesis greatly reduced the affinities (280-2100-fold) of tri- and tetracyclic compounds, whereas this mutation led to a comparatively small reduction (14-fold) in KW-4679 affinity. These results demonstrate that the tested tri- and tetracyclic histamine H1 receptor antagonists which have a tight interaction with the Asp residue are not selective for the histamine H1 receptor. Furthermore, the high selectivity of KW-4679 might be explained by a unique binding pocket, which consists of the Asp residue and other acceptor sites, in the histamine H1 receptor.

Radioligand binding characteristics of the endothelin receptor in the rabbit iris

We previously suggested the presence of functionally atypical endothelin (ET) A receptors in the rabbit iris sphincter. Here, we further characterized the ET receptor by a radioligand-receptor binding study utilizing a membrane fraction of the rabbit iris. In addition, we functionally confirm the presence of an atypical ET(A) receptor in the iris dilator similar to that in the iris sphincter. In binding experiments, [125I]ET-1 was completely displaced by ET-3 in a biphasic fashion, but only partially by BQ-123 and ET(B) ligands. In the presence of RES-701, ET-3 and sarafotoxin (SRTX)-b completely displaced [125I]ET-1 in a monophasic fashion, but with shallow slopes. Moreover, ET-1, ET-3 and SRTX-b completely displaced [3H]BQ-123 with IC50 values of 0.8, 81 and 4.4 nM, respectively, but with slopes of ET-3 and SRTX-b being again shallow. In iris dilator muscles, ET-3 showed lower and SRTX-b showed higher contractile activities than ET-1. SRTX-c was inactive. BQ-123 more preferentially antagonized ET-3 and SRTX-b than ET-1, with the Schild plot slope of SRTX-b being shallow. Thus, functional experiments suggested the presence of atypical ET(A) receptors in the iris dilator similar to the iris sphincter. However, the binding experiments suggested the presence of rather typical ET(A)- and ET(B)-like receptors. Therefore, we apparently failed to show ET binding sites corresponding to functionally atypical ET(A) receptors.

[Our experience of PEG and home care for twelve years]

Percutaneous endoscopic gastrostomy (PEG) was introduced in 1980 by Ponsky et al. This technique does not require general anesthesia and is performed safely and rapidly under local anesthesia without laparotomy. For the past twelve years, in order to maintain enteral alimentation for patients who suffered from dysphagia due to cerebral angiopathy, and to reduce patients' suffering from the long-term placement of a nasogastric tube, PEGs were performed in 150 patients (130 patients for enteral nutrition and 20 for drainage of gastrointestinal contents). We also provided home care service for 30 (27 for enteral nutrition and 3 for decompression) of these patients. We pointed out two problems connected with our retrospective studies for PEG. One is related to the indication of PEG, especially to the evaluation of preoperative status. We suggested a new method for measuring the preoperative status of patients for PEG (PEG-POS score). Retrospective studies showed the PEG-POS score was effective. Using this PEG-POS score, we have not had any early-stage deaths after PEG. Another is related to the home care service for patients with PEG. Consulting the questionnaire survey of families who experienced PEG home care, we examined various problems of home care.

Adenosine A2A receptor antagonists as new agents for the treatment of Parkinson's disease

There is now good reason to believe that blockade of the adenosine A2A receptor could be of value in the treatment of Parkinson's disease. Peter J. Richardson, Hiroshi Kase and Peter G. Jenner review the actions of this receptor in the striatum, emphasizing its ability to modulate the neuronal activity of striatal GABA-releasing output neurones, and showing that recently developed A2A receptor antagonists are capable of reducing the disabling effects of nigral cell degeneration in primates. They conclude that such antagonists may be useful as novel therapeutic agents for the treatment of Parkinson's disease.

Anti-inflammatory and bronchodilator properties of KF19514, a phosphodiesterase 4 and 1 inhibitor

We investigated the effects of KF19514 (5-phenyl-3-(3-pyridyl)methyl-3H-imidazo[4,5-c][1,8]naphthyridin-4 (5H)-one) on bronchoconstriction and allergic inflammation in guinea pigs and on tumor necrosis factor-alpha production in mice. KF19514 inhibited phosphodiesterase 4 (IC50 = 0.40 microM) and phosphodiesterase 1 (IC50 = 0.27 microM) derived from canine tracheal smooth muscles. KF19514 relaxed contracted tracheal smooth muscle and had a potent inhibitory effect on antigen-induced bronchoconstriction (EC50 = 0.058 microM) in vitro. Intravenous administration of KF19514 inhibited histamine-induced bronchoconstriction (ID50 = 2.8 microg/kg i.v.). Moreover, oral administration of KF19514 inhibited anaphylactic bronchoconstriction (ID50 = 0.2 mg/kg p.o.), and eosinophil infiltration in airway stimulated with platelet-activating factor (PAF) or antigen. KF19514 also produced a significant inhibition of tumor necrosis factor-alpha production in mice (ID50 = 0.023 mg/kg p.o.). Finally, KF19514 completely inhibited antigen-induced hyperreactivity at 0.1 mg/kg p.o. These results demonstrate that KF19514 may have efficacy in the treatment of asthma.

Successful one-stage complete removal of an entire intravenous leiomyomatosis in the heart, vena cava, and uterus

The patient was a 61-year-old woman who had intravenous leiomyomatosis (IVL) extending into the right ventricle of the heart from the uterus. Tumors in the heart and the inferior vena cava were removed under cardiopulmonary bypass and then after terminating the cardiopulmonary bypass, tumors in the abdominal cavity including uterine leiomyoma were removed. This is the first case of extended IVL in which all tumors were successfully removed at one time. If a tumor is found in the right ventricle in a woman who had or currently has uterine leiomyoma, IVL should be suspected. Complete one-stage removal of tumors can be performed using cardiopulmonary bypass, and the present patient has shown a favorable outcome.

Primary choriocarcinoma of the uterine cervix: clinical, MRI, and color Doppler ultrasonographic study

Primary choriocarcinoma of the uterine cervix was diagnosed in a 38-year-old Japanese woman 4 months after a normal vaginal, term delivery. The patient had experienced irregular genital bleeding for several weeks. A cervical polypoid tumor was detected by visual inspection 4 months after delivery. Magnetic resonance imaging (MRI) and color Doppler ultrasonography revealed a hypervascular tumor (6 cm) in the uterine cervix. The patient's urinary level of human chorionic gonadotropin (hCG) was 128,000 IU/L. Histological examination of a biopsy of the cervical tumor showed choriocarcinoma. After completion of 2 courses of chemotherapy, the patient underwent a total abdominal hysterectomy. Histological examination of uterus showed no evidence of choriocarcinoma. At present, the patient is free of disease. MRI and color Doppler ultrasonography were useful for diagnosis by detecting the abundant blood flow and central necrosis of the cervical tumor.

Indole derivatives as a new class of steroid 5 alpha-reductase inhibitors

A series of indole derivatives with varied substituents on the alpha, beta-unsaturated double bond were synthesized and evaluated for their ability to inhibit rat prostatic 5 alpha-reductase. Compounds possessing an ethyl substituent at the beta-position of the double bond showed potent inhibitory activity. Among them, (Z)-4-{2-[[3-[1-(4,4'-difluorobenzhydryl)indol-5-yl]-2-pentenoy l]- amino]phenoxy}butyric acid (16, KF20405) showed the maximum potency with an IC50 value of 0.48 +/- 0.086 nM, which was 20-fold higher potency than 1 (MK-906). Compound 16 effectively inhibited DHT production 4 h after a 3 mg/kg oral administration. Several potent indole derivatives, 1 and 2 ((+/-)-ONO-3805), were tested versus rat and human isozymes. Nonsteroidal inhibitors such as indole derivatives and 2 were 2-3 orders of magnitude less potent for human type 2 isozyme than steroidal inhibitor 1 and expressed a significant species deference for these isozymes.

[Usefulness of magnetic resonance imaging in the determination of cervical involvement in endometrial cancer]

One hundred and sixty patients with FIGO stage I and II endometrial cancer entered this study. Magnetic Resonance Imaging (MRI; 61 cases), fractional curettage (110 cases) and hysteroscopy (119 cases) were performed to evaluate the presence of cervical involvement, and the findings were histologically compared with specimens obtained in abdominal hysterectomy. MRI showed the highest sensitivity (90.9%), specificity (96.0%) and diagnostic accuracy (95.1%) for the presence of cervical involvement. In 11 cases with cervical lesions, MRI predicted all 9 cases with invasion deeper than 1.5 mm. From these results we concluded that MRI appeared to be an excellent technique for cervical involvement and it would be a great help in determining the surgical procedure for endometrial cancer.

Case report: an exaggerated placental site with a cervical pregnancy

An exaggerated placental site (EXPS) is an exuberant nonneoplastic proliferation of the intermediate trophoblast at the implantation site. We had a case of an EXPS with a cervical pregnancy. We report on this case, including the patient's clinical course and immunohistological findings.

In vivo regulation of acetylcholine release via adenosine A1 receptor in rat cerebral cortex

The roles of the endogenous adenosine on acetylcholine release via adenosine A1 receptor were investigated in rat cerebral cortex using brain microdialysis. Oral administration of KF15372 (8-dicyclopropylmethyl-1,3-dipropylxanthine), a novel selective adenosine A1 receptor antagonist, at doses of 1.25, 5, and 20 mg/kg, significantly increased the extracellular levels of acetylcholine in rat cerebral cortex. Selective A1 agonist N6-((R)-phenylisopropyl) adenosine (R-PIA) did not affect the extracellular level of acetylcholine by both oral (1.25 mg/kg) and intracortical administrations (0.3 microM) via dialysis probe. These results suggest that the extracellular level of acetylcholine is under tonic inhibitory control of endogenous adenosine via the A1 receptor.

KS-505a, an isoform-selective inhibitor of calmodulin-dependent cyclic nucleotide phosphodiesterase

The effects of KS-505a, a novel microbial metabolite, on the activity of calmodulin-dependent cyclic nucleotide phosphodiesterase (CaM-PDE) were investigated. (1) KS-505a potently inhibited the purified 61 kDa isoenzyme of CaM-PDE from bovine brain and required much higher doses to inhibit the purified 59 kDa isoenzyme of CaM-PDE from bovine heart. The inhibition of both isoenzymes was observed only in the presence of calcium-activated calmodulin (Ca2+/CaM). The IC50 values for the 61 and 59 kDa isoenzymes were 0.17 and 13 microM respectively with 20 microM cAMP as a substrate. (2) Kinetic analysis indicated that the inhibitory mode of KS-505a for the 61 kDa isoenzyme was competitive with respect to Ca2+/CaM; the K1 for KS-505a was 0.089 microM. The inhibition was not competitive with respect to the substrates cAMP or cGMP. (3) KS-505a did not interfere with the interaction between Ca2+/CaM and n-phenyll-naphthylamine, a hydrophobic fluorescent probe, nor was it adsorbed to CaM-conjugated gels in the presence of Ca2+, thereby indicating that KS-505a does not bind to Ca2+/CaM. (4) Trypsin-activated 61 kDa isoenzyme, which lacked the Ca2+/CaM-binding domain, was not inhibited by KS-505a at less than micromolar concentrations. Taken together, these results suggest that KS-505a apparently bound to a site in the Ca2+/CaM-binding domain of the 61 kDa isoenzyme and selectively inhibited Ca2+/CaM-activated 61 kDa isoenzyme activity. (5) In rat hippocampal slices, KS-505a at 10 micronM increased the intracellular cAMP concentration to approximately three times the basal level, whereas in rat striatal slices it had no effect on the cAMP concentration at concentrations of 1.0-10 microM, suggesting that each CaM-PDE isoenzyme functions differentially in these regions. These results demonstrate that KS-505a is a highly potent selective inhibitor both in vitro and in vivo and distinguishes between subfamily members within the CaM-PDE family.

KW-4679, an antiallergic drug, inhibits the production of inflammatory lipids in human polymorphonuclear leukocytes and guinea pig eosinophils

The effects of (Z)-11-[(3-dimethylamino)propylidene]-6,11-dihydrodibenz [b.e.]oxepin-2-acetic acid monohydrochloride (KW-4679), an orally active antiallergic drug, on the production of platelet-activating factor (PAF), leukotriene (LT) and thromboxane (TX) induced by Ca2+ ionophore A23187 were examined. KW-4679 at 10 microM reduced the amount of cell-associated PAF by 52.8% in human polymorphonuclear leukocytes (PMNs). KW-4679 (1-100 microM) also inhibited the release of both LTB4 and TXB2, a stable metabolite of TXA2, by human PMNs in a concentration-dependent manner, but did not influence the release of beta-glucuronidase. The 50% inhibitory concentration (IC50) values for LTB4 and TXB2 release were 5.9 and 6.0 microM, respectively. In guinea pig eosinophils, KW-4679 inhibited the release of peptide LTs at a concentration higher than 10 microM (IC50 = 66.9 microM). KW-4679 failed to inhibit PAF acetyltransferase, 5-lipoxygenase and TX synthase, but inhibited the arachidonic acid release by human PMNs in a concentration-dependent manner in a similar concentration as that inhibiting production or release of lipid mediators (IC50 = 19.5 microM). These results indicate that KW-4679 suppresses LTs and TX release and PAF formation by reducing arachidonic acid release from phospholipids, probably through interference with phospholipase A2. The inhibitory action of KW-4679 on PAF, LT and TX production is a beneficial effect of an antiallergic drug.