Bosentan, a novel synthetic mixed-type endothelin receptor antagonist, attenuates acute gastric mucosal lesions induced by indomethacin and HCl in the rat: role of endogenous endothelin-1

Endothelin-1 has been reported to be responsible for gastric mucosal damage in various experimental models. We evaluated the role of endogenous endothelin-1 in the pathogenesis of gastric mucosal damage induced by indomethacin and HCl in the rat. Rats were given indomethacin (25 mg/kg) subcutaneously, and 15 min later, 0.2N HCl intragastrically. Gastric mucosal damage, gastric endogenous endothelin-1, and gastric mucosal hemodynamics were measured. The effects of bosentan, a mixed endothelin receptor antagonist, on gastric mucosal integrity and hemodynamics were assessed. Gastric endogenous endothelin-1 was significantly elevated at 20 min, gastric mucosal blood flow began to decrease significantly at 25 min, and gastric damage occupied 52.2% of the total glandular mucosa at 135 min after injection of indomethacin. Intragastric pretreatment with bosentan (5, 10, 30, and 60 mg/kg) significantly attenuated gastric damage, to 26.1%, 7.7%, 3.6%, and 1.6%, respectively, of the total glandular mucosa. Bosentan (60 mg/kg) prevented the initial decrease of blood flow and, even at 135 min, improved blood flow and hemoglobin oxygen saturation significantly. We suggest that indomethacin-induced endogenous endothelin-1 diminishes gastric mucosal blood flow and tissue oxygenation and ultimately causes gastric damage. Endogenous endothelin-1 may play an important role in the pathogenesis of the acute gastric mucosal lesions induced by indomethacin and HCl.

Role of endothelin-1 in astrocyte responses after acute brain damage

We examined the possibility of the involvement of endothelin (ET)-1, a potent vasoactive peptide, in the process of astrocyte proliferation after brain injury. Acute brain damage in rats was induced by cold-injury. Astrocytes changed from a differentiated state to an immature, RC-1-positive state immediately after the injury. In the injured site, the level of ET-1-like immunoreactivity in the tissue was significantly increased on the first postoperative day and was sustained at a high level for 5 days. ET(B) receptor mRNA was markedly but transiently down-regulated only on the first day after the injury. Brain extracts (BE) were prepared from the injured tissues, and their effects on the proliferative characteristics of astrocytes were examined in primary culture of astrocytes. The flat morphology, which was observed in association with cell proliferation, and DNA synthesis of astrocytes were enhanced by treatment with each of the BE from 1 (D1-BE), 3 and 5 days after the injury. A monoclonal antibody that recognizes the C-terminus of rat ET-1 and ET-3 inhibited the DNA synthesis of astrocytes induced by D1-BE. These results provide experimental evidence that ET-1 may participate in the initiation of gliosis in the acute phase of brain damage.

Noradrenergic activity and spontaneous recurrence of methamphetamine psychosis

The process that triggers flashbacks due to previous methamphetamine (MAP) psychosis was studied in 28 flashbackers, along with 84 non-flashbackers with a history of MAP psychosis. We measured plasma monoamine metabolite levels in 12 of the flashbackers and eight of the non-flashbackers, along with 28 normal controls. Most flashbackers had undergone frightening experiences during previous MAP use. The dominant triggering factor was a mild fear of other people. Plasma norepinephrine (NE) levels in the 12 flashbackers were increased during flashbacks. Thus, MAP use associated with threatening experiences may have increased sensitivity to stressors, leading to the occurrence of flashbacks, including exaggerated noradrenergic activity.

Novel regulation of delta-aminolevulinate synthase in the rat harderian gland

The mode of expression of delta-aminolevulinate synthase (ALAS), as well as that of mRNAs for other heme pathway enzymes, was examined in the rat Harderian gland. Northern blot and in situ hybridization analyses demonstrated that the non-specific ALAS (ALAS-N) mRNA is highly expressed in this tissue, whereas the erythroid-specific ALAS (ALAS-E) mRNA is not. Immunoblot analysis of ALAS also confirmed this finding at the protein level. ALAS-N mRNA was maximally induced in the Harderian gland and was not increased further by treatment of animals with 2-allyl-2-isopropylacetamide (AIA). The levels of mRNAs for other heme pathway enzymes, i.e., delta-aminolevulinate dehydratase, porphobilinogen deaminase, uroporphyrinogen decarboxylase, and coproporphyrinogen oxidase, also were increased markedly in the Harderian gland and not influenced by AIA treatment. The level of ferrochelatase (FeC) mRNA in the gland was, however, lower than that in the liver. The gland contained an extremely high level of protoporphyrin, while heme was undetectable. Microsomal heme oxygenase-1 (HO-1) mRNA levels were significantly higher in the Harderian gland than in the liver. When isolated glands were incubated with hemin in vitro in organ cultures, the level of HO-1 mRNA was increased, whereas the ALAS-N mRNA level was not. These findings indicate that markedly elevated levels of protoporphyrin and extremely low levels of heme in the Harderian gland are the results of both decreased expression of FeC and markedly increased expression of ALAS-N and HO-1. The constitutive expression of the ALAS-N gene in the Harderian gland suggests a novel transcriptional control mechanism of this gene.

Studies on endothelium-dependent vasorelaxation by hydralazine in porcine coronary artery

Hydralazine relaxed porcine coronary artery strips in a concentration-dependent manner by distinct endothelium-dependent and endothelium-independent actions. With lower doses (< or = 10(-6) M), the hydralazine-induced relaxation appears to be completely endothelium-dependent and we designed the present study to elucidate the mechanisms of this endothelium-dependent relaxation. Hydralazine (10(-6) M)-induced endothelium-dependent relaxation was not affected by the presence of 10(-5) M indomethacin, 10(-3) M L-NG-nitro-arginine (L-NOARG) or 10(-5) M haemoglobin, and was accompanied by accumulation of cGMP but not of cAMP in artery strips. There was a close time-dependent parallel relationship between endothelium-dependent relaxation and accumulation of cGMP induced by hydralazine (10(-6) M). The endothelium-dependent relaxation and accumulation of cGMP induced by hydralazine showed much slower kinetics than those induced by ionomycin (10(-7) M). Pretreatment of the strips with actinomycin D (10 micrograms/ml) significantly inhibited not the endothelium-dependent relaxation and accumulation of cGMP induced by ionomycin (10(-7) M) but those induced by hydralazine (10(-6) M). These results suggest that hydralazine induces endothelium-dependent vasorelaxation via the slow accumulation of cGMP in the strips. This does not occur through the release of nitric oxide or prostaglandin I2 but through immediate transcription and probably expression of a molecule in the endothelium.

Serologic survey for HTLV-I in Kanagawa Prefecture

To investigate the seroprevalence of HTLV-I in Kanagawa Prefecture (central Japan), we tested the sera of 8,264 healthy volunteers and 2,414 pregnant women. Of the 8,264 healthy volunteers, 66 (0.80%) were seropositive. The seroprevalence of HTLV-I in the pregnant women was 14/2,414 (0.58%), and this rate was almost identical to that in the healthy female volunteers 15 to 44 years of age (0.59%). These figures indicate that the seroprevalence of HTLV-I in Kanagawa Prefecture is very low and that sexual contact may not be an important contributory factor.

Molecular cloning and sequencing of cDNA encoding plasma countertrypin, a member of mammalian fetuin family, from the Mongolian gerbil, Meriones unguiculatus

Complementary DNA clones coding for countertrypin were isolated from a liver cDNA library of the Mongolian gerbil, and sequenced. They contained one open reading frame encoding 348 amino acid residues, which were assigned to consist of an 18-residue signal peptide and a 330-residue mature protein. The amino acid sequence was about 74% identical with mouse countertrypin and rat fetuin, 60% with bovine fetuin, and 55% with human alpha2HS glycoprotein, indicating that this protein belongs to the mammalian fetuin family. The members of this family are known to consist of three domains, i.e., two tandemly arranged cystatin domains (D1 and D2) and an unrelated domain (D3) located at the C-terminal region. When compared with the other members of this family, D3, especially its N-terminal half, varies greatly with deletion or insertion as well as nucleotide substitutions even among three rodent species, i.e., gerbil, rat, and mouse. The sequence comparison also suggests that the conformation of human alpha2HS glycoprotein differs greatly from that of other members of this family. A molecular phylogenetic tree of 7 members, constructed on the basis of the synonymous substitution rate of D1 and D2, shows that the gerbil gene diverged prior to the separation of mouse and rat.

[A 36-year-old woman with acute onset left hemiplegia and anosognosia]

We report a 36-year-old woman with right hemiplegia, anosognosia, and rapidly deteriorating course. She was well until the end of January, 1995 when she had an onset of fever, sputum, and cough. A 5 x 5 tumor was found in her left lower lobe. She was admitted to the Pulmonary Medicine on May 24, 1995 when she was 36-year-old. General physical examination was unremarkable. Bone scintigraphy revealed increased uptake in the skull, sternum, right scapula, vertebrae, right femur, and in ribs. Cranial CT scan revealed a large mass lesion in the right frontal subcortical region with central low density and peripheral high density areas, and small low density lesions in the right thalamic area and in the right posterior frontal region; ring enhancement was observed in the latter two lesions. On the second day of admission, she noted left-sided weakness which improved by corticosteroid treatment. On June 17, there was a sudden onset of left hemiparesis and a neurologic consultation was asked. Upon neurologic examination, she appeared somnolent but could understand verbal commands. She showed constructional apraxia, neglect of the left hemisphere, and anosognosia. Cranial nerves were unremarkable. Motor-wise, she showed flaccid left hemiplegia. Deep tendon reflexes were exaggerated on the left and the plantar response was extensor bilaterally. Nuchal stiffness was noted. Her cranial CT scan on June 17 revealed enlargement of the right frontal mass lesion. The subsequent course was complicated by DIC and progressive worsening of her consciousness. On June 18, she was comatose and pupillary light reflex was lost. She developed Cheyne-Stokes respiration and expired on that evening. The patient was discussed in a neurological CPC, and the chief discussant arrived at the conclusion that the patient had a primary adenocarcinoma in the lung with multiple metastases including the brain. The fulminant terminal course was ascribed to hemorrhage within the tumor and subsequent central type of transtentorial herniation. Opinions were divided regarding the cause of hemorrhage; some participants thought hemorrhage was caused by DIC. Post-mortem examination revealed an adenocarcinoma arising at the S6 segment of the left lung with multiple organ metastases. In the brain, a huge hemorrhagic metastasis was found in the right frontal lobe and a non-hemorrhagic metastasis in the right thalamic region. Probably, the size of the metastases influenced the occurrence of hemorrhage. The direct cause of the death was transtentorial herniation.

[Astrocytes and endothelins: possibilities for tissue-repair in damaged central nervous system]

Endothelins and their receptor of type B (ETBR) that couples with G-protein are widely distributed in the mammalian central nervous system (CNS). ETBR mainly exists on astrocytes, and endothelins exert mitogenic action on astrocytes through stimulation of the receptor. The intracellular signaling of ETBR in astrocytes is converged in the activation of mitogen-activated protein kinase through a protein kinase C-dependent pathway and a pertussis toxin-sensitive G-protein-mediated pathway. We demonstrated that cultured astrocytes. When differentiated and growth-arrested by treatment with dibutyryl cyclic AMP, abundantly expressed ETBR and these cells immediately entered into a proliferative state in response to endothelin-1 at the plasma level. This has the following physiological implication in vivo: plasma-derived endothelin-1 intrudes into parenchyme upon CNS damage, and it initiates astrogliosis through activation of ETBR. We used two models of CNS injury in rats. The first is a brain edema model induced by cold-injury, and the second is a spinal cord injury model, both of which allow plasma to exude into the injured tissues and subsequently trigger sequential proliferative responses of astrocytes after the injury. Anti-endothelin monoclonal antibody and SB209670, an endothelin receptor antagonist, specifically and potently inhibited astrocytic proliferation 24 hr after the injury. It is concluded that endothelin-1 plays a key role for initiation of astrocytic proliferation in the acute phase of CNS damage.

Histopathological aspects of dural arteriovenous fistulas in the transverse-sigmoid sinus region in nine patients

OBJECTIVE

In recent years, dural arteriovenous fistulas (DAVFs) have been primarily thought to be acquired lesions, formed after sinus thrombosis. The pathogenesis of DAVF, however, is still controversial. We have studied histopathological aspects of DAVFs in resected specimens obtained from nine patients, to obtain clues to the pathogenesis of DAVFs.

METHODS

Histological comparison was made among nine DAVF cases and five control cases without venous sinus disease. In addition, the relationship between the clinical course and histological aspects was investigated.

RESULTS

The essential abnormality found was a connection between the dural arteries and the dural veins within the venous sinus wall, through small vessels averaging approximately 30 microns in diameter. By using several staining methods, we confirmed that the vessels were part of the venous system; we named these dilated venules "crack-like vessels."

CONCLUSIONS

The development of abnormal communications between dural arteries and dural veins (crack-like vessels) is regarded as the essential part of the pathogenesis of DAVFs, and sinus thrombus is not thought to be an essential lesion of DAVFs. It might be postulated that sinus hypertension caused by stenocclusive disease of the venous sinuses triggers the development of fistulous connections between arteries and veins in the dural wall, which may result in increasingly dilated venules and the formation of DAVFs.

Triplet repeat polymorphism in the transmembrane region of the MICA gene: a strong association of six GCT repetitions with Behçet disease

A member of a novel family of the human major histocompatibility complex (MHC) class I genes termed MIC (MHC class I chain-related genes), MICA, has been recently identified near the HLA-B gene on the short arm of human chromosome 6. The predicted amino acid sequence of the MICA chain suggests that it folds similarly to typical class I chains and may have the capacity to bind peptides or other short ligands. Therefore, MICA is predicted to have a specialized function in antigen presentation or T cell recognition. During nucleotide sequence analyses of the MICA genomic clone, we found a triplet repeat microsatellite polymorphism of (GCT/AGC)n in the transmembrane (TM) region of the MICA gene. In 68 HLA homozygous B cell lines, 5 distinct alleles of this microsatellite sequence were detected. One of them contained an additional one base insertion that created a frameshift mutation resulting in a premature termination codon in the TM region. This particular allele may encode a soluble, secreted form of the MICA molecule. In addition, we have investigated this microsatellite polymorphism in 77 Japanese patients with Behcet disease, which is known to be associated with HLA-B51. The microsatellite allele consisting of 6 repetitions of GCT/AGC was present at significantly higher frequency in the patient group (Pc = 0.00055) than in a control population. Furthermore, the (GCT/AGC)6 allele was present in all B51 positive patients and in an additional 13 B51 negative patients. These results suggest the possibility of a primary association of Behcet disease with MICA rather than HLA-B.

Methamphetamine psychosis: spontaneous recurrence of paranoid-hallucinatory states and monoamine neurotransmitter function

We studied the process that triggers spontaneous recurrences of methamphetamine (MAP) psychosis, a phenomenon known as flashbacks, in 28 female patients who experienced flashbacks, by comparing them with 92 female nonflashbackers with a history of previous MAP psychosis. The study evaluated plasma monoamine neurotransmitter function in 12 of the 28 flashbackers and in 8 of the 92 nonflashbackers. Control data were obtained from 28 normal, healthy females composed of 13 MAP users and 15 nonusers, none of whom became psychotic. The 28 flashbackers had experienced significantly greater frequencies of threatening events and frightening paranoid-hallucinatory states during previous MAP abuse than the 92 nonflashbackers. The dominant triggering factor was a mild fear of other persons. Plasma norepinephrine (NE) levels were significantly higher in the 12 flashbackers during flashbacks than during periods of normalcy and were significantly higher than those in the 13 user and 15 nonuser control subjects. Plasma NE levels in the 12 flashbackers during periods of normalcy were significantly higher than those in the 13 user control subjects. The eight nonflashbackers had significantly higher NE levels than the 13 user control subjects. This suggests that an increase in peripheral noradrenergic activity may be related to the occurrence of flashbacks. The present study suggests that repeated MAP use with frightening experiences may induce sensitivity to psychosocial stressors. A mild fear of other persons may have actualized the encoded frightening memories associated with the frightening experiences via increased sensitivity to psychosocial stressors. Thus, flashbacks may have been caused through an increase in peripheral noradrenergic activity.

Pregnancy increases ET-1-induced contraction and changes receptor subtypes in uterine smooth muscle in humans

The purpose of the present study was to investigate whether pregnancy affects endothelin (ET)-1-induced contraction, the density ofET receptors, and the ratio of receptor subtypes (ET(A) and ET(B)) in uterine smooth muscle in humans. We also investigated which ET receptor subtypes mediate ET-1-induced contraction in the human uterus. In uterine membrane preparations, (125)I-labeled ET-1 ((125)I-ET-1) binding sites (Bmax) in pregnant women did not differ from those in age-matched nonpregnant women (596.2 +/- 107.1 vs. 512.1 +/- 167.7 fmol/mg protein). The dissociation constant (Kd) in pregnant women did not differ from that in nonpregnant women. Competitive displacement experiments with (125)I-ET-1 binding to the membranes using BQ-123 (ET(A) receptor antagonist) showed that the percentage of ET(A) receptors in uterine muscle was significantly higher in pregnant women than in nonpregnant women (P < 0.01). The calculated ratios of ET(A) to ET(B) receptors in pregnant and nonpregnant uteri were 92:8 and 68:32, respectively. Combination treatment with BQ-788 (ET(B) receptor antagonist) completely inhibited the BQ-123-resistant component of (125)I-ET-1 specific binding. ET-1 caused dose-dependent contractions in isolated human uteri from both pregnant and nonpregnant women. The maximum response was markedly greater in pregnant women than in nonpregnant women, whereas pD2 (-log[EC50]) values did not differ between pregnant and nonpregnant uteri. In pregnant human uterus, BQ-123 (10(-6) M) significantly shifted the dose-dependent curve of ET-1 response to the right, whereas BQ-3020 (ET(B) receptor agonist) did not cause contraction. These results suggested that ET-1-induced contraction of the human uterus is mediated through only ET(A) receptors and that ET-1-induced uterine contraction in humans is markedly increased during pregnancy. In addition, the present study suggests that, although (125)I-ET-1 Bmax are not altered during pregnancy, the proportion of ET(A) receptors is increased and that of ET(B) receptors is decreased in the pregnant human uterus.

The seroprevalence of HTLV-I in patients with ocular diseases, pregnant women and healthy volunteers in the Kanto district, central Japan

HTLV-I has been shown to be related to the development of inflammatory diseases in various organs such as the eyes, lungs and joints. In south-west Japan where HTLV-I is highly endemic, the term 'HTLV-I associated complex' has been approved. To investigate the seroprevalence of HTLV-I in the Kanto district in central Japan, we have estimated the frequency of seropositivity to HTLV-I in 2,110 patients with various ocular diseases and 2,683 pregnant women, in addition to 5,336 healthy volunteers. Of the healthy volunteers, only 42 (0.79%) were seropositive, and the HTLV-I seroprevalence in pregnant women was also only 16/2,683 (0.60%) which was almost equal to that in female healthy volunteers aged 15-44 years (0.59%). In patients with various ocular diseases, however, there was significantly higher seroprevalence of HTLV-I (2.32%) compared with healthy volunteers in each sex (male: p = 0.0029; female: p = 0.000023). These results suggest that the seroprevalence of HTLV-I in the Kanto district is much lower than in south-west Japan. On the other hand, HTLV-I infection was shown to be correlated to ocular diseases also in the Kanto district. In particular, we found a higher seroprevalence of HTLV-I in patients with inflammatory ocular disease, such as endogenous uveitis, episcleritis, retinitis pigmentosa and degenerative choroiditis. This possibly suggests a causative role of HTLV-I in the development of these inflammatory ocular diseases also where HTLV-I is not endemic.

Dose-intensive weekly chemotherapy for treatment of relapsed small-cell lung cancer

PURPOSE

This study was undertaken to determine the activity and toxicity of dose-intensive weekly chemotherapy (cisplatin, vincristine, doxorubicin, and etoposide [CODE] regimen) for previous treated, recurrent small-cell lung cancer (SCLC).

PATIENTS AND METHODS

The 17 patients with relapsed SCLC entered onto the study were to receive intensive weekly chemotherapy with the CODE regimen. All 17 patients had been heavily pretreated with some form of cisplatin-based combination chemotherapy. Six patients had received previous chemotherapy with CODE and one patient with cisplatin and etoposide (PE) as induction therapy. Nine patients had been treated with concurrent or sequential PE plus thoracic irradiation (TRT). The median time off chemotherapy was 6.7 months (range, 3.3 to 72). Patients were treated with 9 weeks of the CODE regimen. Response, survival, and toxicity data were noted.

RESULTS

All 17 patients were assessable for response, survival, and toxicity. Fifteen of 17 patients (88.2%) had an objective response, with five complete responses (CRs; 29%) and 10 partial responses (PRs; 58.8%). The median durations of response and survival were 156 days and 245 days, respectively. Myelosuppression was significant, with 76% of patients developing grade 4 leukopenia. No treatment-related death was observed.

CONCLUSION

The CODE regimen is highly active in the treatment of relapsed SCLC with an encouraging survival outcome.

Monoamine neurotransmitter metabolites and spontaneous recurrence of methamphetamine psychosis

The present study was conducted to evaluate plasma levels of monoamine neurotransmitter metabolites in spontaneous recurrences of methamphetamine psychosis (i.e., flashbacks). The subjects were 50 physically healthy females comprised of 25 who experienced flashbacks (flashbackers), 18 who did not experienced methamphetamine psychosis, and 9 who were currently suffering from persistent methamphetamine psychosis. The control data were available from 28 normal healthy females, of whom 20 had previously abused methamphetamine (users) and 8 who had not (nonusers), none of whom had ever become psychotic. Plasma levels of norepinephrine (NE), dopamine (DA), and 5-hydroxytryptamine (5-HT), and their respective metabolites were assayed. Plasma NE levels were significantly higher in the 25 flashbackers during their flashbacks than during their periods of normalcy, and were significantly higher than those in the 20 user and 8 nonuser controls. Plasma 3-methoxy-4-hydroxyphenylglycol (MHPG) levels during flashbacks were significantly higher than those in the 20 user controls. The nine subjects with persistent methamphetamine psychosis had significantly higher NE levels than the user and nonuser controls. The 16 nonflashbackers had significantly higher MHPG levels than the user controls. The present study suggests that an increase in peripheral noradrenergic activity is related to the occurrence of flashbacks.

Zinc depletion suppresses tumor growth in mice

The hypothesis that in tumor-bearing animals an increase of host hepatic zinc metallothionein (Zn-MT) causes a restriction of zinc in the tumor tissue was studied. Three types of tumors were induced in laboratory mice by cell transplant. Tumor growth appears to be inhibited under zinc-deficient conditions, even in cases where zinc deficiency was started after tumor cell transplant. The survival times of tumor-bearing mice were prolonged by administration of cadmium chloride, which induces the synthesis of a combined zinc-cadmium metallothionein derivative in the host liver, but not in the tumor tissue, leading to an increase of hepatic zinc in the treated animals. The uptake of 65Zn by the liver of Cd-treated, tumor bearing mice was significantly higher than that of controls whereas uptake of 65Zn by tumor cells was significantly higher in controls than in the treated animals. These results suggest that restriction of zinc intake suppresses tumor growth.

Differences in the change in the time course of plasma endothelin-1 and endothelin-3 levels after exercise in humans. The response to exercise of endothelin-3 is more rapid than that of endothelin-1

Several studies have indicated that endothelin-1 (ET-1) and endothelin-3 (ET-3) are produced by different cells. Although ET-1 is produced by vascular endothelial cells, these cells do not produce ET-3. The presence of ET-3 in the brain of several species suggests that ET-3 is a novel neuropeptide. It is unclear whether there are differences in the release of ET-1 and ET-3 under various physiological conditions in humans. In the present study, we measured the plasma concentrations of both ET-1 and ET-3 before and after endurance exercise on a cycle ergometer. Male athletes exercised on a cycle ergometer for 30 min at intensity of 130% of their individual ventilatory threshold (VT), which is intense exercise. Plasma ET-1 and ET-3 were greatly elevated by exercise, but there was a marked difference in the time-course of the change in plasma concentration between the two peptides. The level of ET-1 peaked 30 min after exercise, whereas that of ET-3 peaked immediately after exercise. Thus, plasma ET-3 increased faster than plasma ET-1 after exercise. The exercise-induced change in the time course in plasma ET-3, but not in ET-1, is similar to that in plasma norepinephrine which is a neurotransmitter, suggesting that the rapid elevation in plasma ET-3 is partly attributable to the neuronal response to exercise. The observed difference in the change in the time course of plasma ET-1 and ET-3 levels suggests that the mechanisms by which exercise alters the release and/or synthesis of these two peptides differ.

Phase II study of high-dose dexamethasone-based association in acute and delayed high-dose cisplatin-induced emesis--JCOG study 9413

Thirty-three patients with lung cancer receiving 80 mg m(-2) cisplatin were treated with high-dose dexamethasone (32 mg m(-2) on days 1-3, 16 mg m(-2) on day 4 and 8 mg m(-2) on day 5) combined with granisetron on day 1 and metoclopramide on days 2-5. Twenty-eight (85%) patients had no nausea or vomiting on day 1, and 16 (48%) achieved total control on days 1-5 with acceptable toxicity. High-dose dexamethasone for cisplatin-induced delayed emesis should be further evaluated in a phase III trial.

Cloning and expression localization of cDNA for rat homolog of TRP protein, a possible store-operated calcium (Ca2+) channel

A 3.2 kbp cDNA clone encoding a possible candidate for the store-operated Ca2+ channel was isolated from a rat brain cDNA library. The deduced amino acid sequence was 51.8% identical to TRP encoded by a Drosophila trp (transient receptor potential) gene and contained ankyrin motifs, a coiled-coil structure and six transmembrane segments similar to the previously identified TRP family and named as TRP-R (rat TRP). By in situ hybridization histochemistry of rat body on embryonic day 15, no significant expression signal for TRP-R was detected. On embryonic day 20 and postnatal day 1, the expression signals were most evident in the septum, cerebral cortical plate and hippocampal neuronal layers. On postnatal day 7 and thereafter the expression in the cerebral cortex and the septum decreased progressively, and weak expression remained only in the CA1 and CA2 neuronal layers of the hippocampus in the brain on postnatal day 21 and 49. This limited spatiotemporal expression of this novel molecule. TRP-R, suggests that it is involved in some specific functions related to the neuronal differentiation.