Processing of CD109 by furin and its role in the regulation of TGF-beta signaling.

CD109 is a glycosylphosphatidylinositol (GPI)-anchored glycoprotein, whose expression is upregulated in squamous cell carcinomas of the lung, esophagus, uterus and oral cavity. CD109 negatively regulates transforming growth factor (TGF)-beta signaling in keratinocytes by directly modulating receptor activity. In this study, we further characterized CD109 regulation of TGF-beta signaling and cell proliferation. We found that CD109 is produced as a 205 kDa glycoprotein, which is then processed in the Golgi apparatus into 180 kDa and 25 kDa proteins by furin (furinase). 180 kDa CD109 associated with GPI-anchored 25 kDa CD109 on the cell surface and was also secreted into the culture medium. To investigate whether furinase cleavage of CD109 is necessary for its biological activity, we mutated arginine 1273 in the CD109 furinase cleavage motif (amino acid 1270-RRRR-1273) to serine (R1273S). Interestingly, CD109 R1273S neither significantly impaired TGF-beta signaling nor affected TGF-beta-mediated suppression of cell growth, although it was expressed on the cell surface as a 205 kDa protein. Consistent with this finding, the 180 kDa and 25 kDa CD109 complex, but not CD109 R1273S, associated with the type I TGF-beta receptor. These findings indicate that processing of CD109 into 180 kDa and 25 kDa proteins by furin, followed by complex formation with the type I TGF-beta receptor is required for the regulation of TGF-beta signaling in cancer cells and keratinocytes.

Responses to 5-HT in morphologically identified neurons in the rat substantia gelatinosa in vitro.

Bath application of 5-HT (1-1000 muM) induced a tetrodotoxin (TTX)-resistant outward current at the holding membrane potential (V(H)) of -50 mV in 104/162 (64.2%) of substantia gelatinosa (SG) neurons from the rat spinal cord in vitro. The 5-HT-induced outward current was suppressed by an external solution containing Ba(2+), or a pipette solution containing Cs(2)SO(4) and tetraethylammonium. It was reversed near the equilibrium potential of the K(+) channel. The response to 5-HT was abolished 30 min after patch formation with a pipette solution containing guanosine-5-O-(2-thiodiphosphate)-S. The 5-HT-induced outward current was mimicked by a 5-HT(1A) agonist, (+/-)-8-hydroxy-2-(di-n-propylamino) tetralin hydrobromide, and suppressed by a 5-HT(1A) antagonist, WAY100635, suggesting the 5HT(1A) receptor-mediated activation of K(+) channels in the outward current. In 11/162 (6.8%) SG neurons, 5-HT produced an inward current, which was mimicked by a 5-HT(3) agonist, 1-(m-chlorophenyl)-biguanide (mCPBG). The 5-HT-induced outward currents were observed in vertical cells (21/34) and small islet cells (11/34), while inward currents were induced in islet cells (1/5) and small islet (4/5) cells, but not in vertical cells. It is known that most vertical cells and islet cells in the SG are excitatory (glutamatergic) and inhibitory interneurons, respectively, while small islet cells consist of both excitatory and inhibitory neurons. Bath application of 5-HT or mCPBG increased the amplitude and the frequency of spontaneous inhibitory postsynaptic currents (sIPSCs), but no neurons showed a decrease in sIPSC. Furthermore, frequency, but not amplitude, of miniature IPSCs increased with perfusion with 5-HT in the presence of TTX. These findings, taken together, suggest that 5-HT induces outward currents through 5-HT(1A) receptors in excitatory SG neurons. These findings also suggest that the inward currents are post- and presynaptically evoked through 5-HT(3) receptors, probably in inhibitory neurons.

Action of neuropeptide Y on nociceptive transmission in substantia gelatinosa of the adult rat spinal dorsal horn.

Effects of neuropeptide Y (NPY) on substantia gelatinosa neurons were investigated in adult rat spinal cord slices using blind whole-cell patch-clamp technique. Bath application of NPY (1 microM) induced a membrane hyperpolarization, resulting in a suppression of the dorsal root stimulation-induced action potentials in 24% of the substantia gelatinosa neurons tested. In voltage clamp mode, NPY produced an outward current dose-dependently in about one third of substantia gelatinosa neurons at the holding potential of -60 mV, which was not affected by tetrodotoxin (1 microM). The NPY-induced current was suppressed by perfusion with a Ba2+-containing external solution and a Cs2SO4 or tetraethylammonium-containing pipette solution. In addition, The NPY-induced outward currents reversed its polarity near the equilibrium potential of K+ ions (-93 mV). The response to NPY recorded with guanosine-5'-O-(2-thiodiphosphate)-beta-S (GDP-beta-S) containing pipette solution was abolished 30 min after patch formation, suggesting that the response was mediated by the G-protein-coupled receptors. Application of an NPY-Y1 selective agonist, [Leu(31), Pro(-34)]-NPY (1 microM), for 30 s also induced an outward current with a similar time course and amplitude to that induced by NPY. On the other hand, the NPY response was blocked by a simultaneous application of NPY-Y1 selective antagonist, BIBP 3226 (1 microM). No significant changes were found in amplitude and frequency of miniature excitatory postsynaptic currents and dorsal root evoked excitatory postsynaptic currents by NPY. In addition, NPY did not affect both of the miniature inhibitory postsynaptic currents and evoked inhibitory postsynaptic currents, mediated by either the GABA or glycine receptor. These findings, taken together, suggest that NPY produces an outward current in substantia gelatinosa neurons through G-protein coupled, and NPY-Y1 receptor-mediated activation of K+ channels without affecting presynaptic components. The inhibition of the synaptic transmission from the primary fibers to the substantia gelatinosa neurons is considered to contribute to the antinociceptive effects of NPY.

Functional reorganization of the spinal pain pathways in developmental and pathological conditions.

Following inflammation, a subpopulation of Abeta afferents that terminates preferentially in deeper laminae have been shown to extend their axons to the superficial dorsal horn, particularly substantia gelatinosa (SG). Similarly, SG neurons in immature spinal cord receive mainly Abeta afferent inputs. To clarify whether the reorganized sensory pathway in the inflamed rats has a functional similarity with that in the developmental state, we compared synaptic inputs from primary afferents using in vitro and in vivo patch-damp recordings from SG neurons. SG neurons in the mature state had monosynaptic inputs from Adelta and C afferents, while only a few neurons received inputs from Abeta afferents. Following inflammation, the Abeta afferents extended their axons to SG and established functional monosynaptic transmission. Meanwhile, SG neurons in the immature state received preferentially Abeta as well as Adelta afferent inputs, and the majority of Abeta afferent inputs were monosynaptic. These observations support the idea that the sprouting of the large afferent fibres observed in inflamed rats is, at least in part, a regeneration process. However, the process, maybe distinct at some point from the process during development, therefore, produces pathological pain. Though the idea that the regeneration mimics the developmental process has been widely accepted, other possibilities cannot be excluded.

Analysis of receptive fields revealed by in vivo patch-clamp recordings from dorsal horn neurons and in situ intracellular recordings from dorsal root ganglion neurons.

It has been thought that spinal dorsal horn neurons receive convergent inputs from not only somatosensory but also visceral pathways. For instance, the referred pain is presumed to be due to the convergence of sensory inputs from cardiac and shoulder receptive fields. However, precise investigation has not been made from dorsal horn neurons yet, because of difficulty in studying the pathways from those regions by means of conventional electrophysiology. The purpose of this study is to clarify the convergent inputs to single dorsal horn neurons from wide receptive fields using an in vivo patch-clamp recording technique from the superficial spinal dorsal horn and an intracellular recording from dorsal root ganglion neurons that keep physiological connections with the peripheral sites. Identified dorsal root ganglion neurons received an input from a quite small area, about 1 x 1 mm in width of the skin. In contrast, substantia gelatinosa neurons in the spinal cord received inputs from an unexpectedly wide area of the skin. Previous extracellular recordings have, however, revealed that substantia gelatinosa neurons have small receptive field. This discrepancy is probably due mainly to an availability of the in vivo patch-clamp method to analyze sub-threshold synaptic responses. In contrast, the extracellular recording technique allows us to analyze predominantly the firing frequency of neurons. Thus, the in vivo patch-clamp recordings from dorsal horn neurons and the intracellular recordings from DRG neurons will be useful for well understanding the sensory processing in the spinal cord.

Nociceptin inhibits excitatory but not inhibitory transmission to substantia gelatinosa neurones of adult rat spinal cord.

Although intrathecal administration of nociceptin, an endogenous ligand of the opioid receptor-like1 receptor, exhibits an antinociceptive effect in various pain models, cellular mechanisms underlying this action are still unknown. Here, we investigated the effects of nociceptin on excitatory and inhibitory synaptic transmission to substantia gelatinosa neurones of an adult rat spinal cord slice with an attached dorsal root by use of the blind whole-cell patch-clamp technique; this was done under the condition of a blockade of a hyperpolarising effect of nociceptin. In about 70% of the neurones examined, nociceptin (1 microM) reduced the amplitude of glutamatergic excitatory postsynaptic currents (EPSCs) which were monosynaptically evoked by stimulating Adelta- or C-afferent fibres; the inhibition of C-fibre EPSCs (50+/-6%, n=11) was larger than that of Adelta-fibre EPSCs (30+/-5%, n=23; P<0.05). Each of the nociceptin actions was dose-dependent in a concentration range of 0.1 to 1 microM, and was largely suppressed by a selective opioid receptor-like1 receptor antagonist, 1-[(3R,4R)-1-cyclooctylmethyl-3-hydroxymethyl-4-piperidyl]-3-ethyl-1,3-dihydro-2H-benzimidazol-2-one (3 microM). Nociceptin (1 microM) also decreased miniature EPSCs frequency by 22+/-6% (n=7) while not affecting their amplitude. Responses of substantia gelatinosa neurones to bath-applied alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (10 microM) were not changed by nociceptin. Both electrically evoked and miniature inhibitory postsynaptic currents, mediated by either the GABA(A) or glycine receptor, were unaffected by nociceptin. These results indicate that nociceptin suppresses excitatory but not inhibitory synaptic transmission to substantia gelatinosa neurones through the activation of the opioid receptor-like1 receptor; this action is pre-synaptic in origin. Considering that the substantia gelatinosa is the main part of termination of Adelta- and C-fibres transmitting nociceptive information, the present finding would account for at least a part of the inhibitory action of nociceptin on pain transmission. Nociceptin could inhibit more potently slow-conducting than fast-conducting pain transmission.

Nociceptin-induced outward current in substantia gelatinosa neurones of the adult rat spinal cord.

Nociceptin (NOC), also known as orphanin FQ, is a newly discovered endogenous ligand for the opioid receptor-like1 (ORL1) receptor. Although NOC has been shown to modulate nociceptive transmission, mechanisms for this action are still unknown. In the present study, actions of NOC on substantia gelatinosa (SG) neurones were examined in adult rat spinal cord slice preparations by using the whole-cell patch-clamp technique. NOC at a concentration of 1 microM induced an outward current having an amplitude of 26+/-5 pA (n=68) at a holding potential of -70 mV; this action was dose-dependent with an EC(50) value of 0.23 microM (Hill coefficient: 1.5). The NOC current reversed its polarity at a potential which was close to the equilibrium potential for K(+), as calculated by the Nernst equation (n=4). The NOC current had slope conductances of 0.80+/-0.15 nS and 0.50+/-0.13 nS (n=4) in voltage ranges of -120 to -140 mV and of -60 to -90 mV, respectively. The NOC current was inhibited by Ba(2+) (100 microM; by 56+/-8%, n=4) but not by 4-aminopyridine (4-AP; 1 mM; n=4) and tetraethylammonium (TEA; 5 mM; n=4). The NOC current was not affected by tetrodotoxin (TTX; 1 microM; n=4) and also by a non-specific opioid receptor antagonist, naloxone (1 microM; n=4). When examined using some inhibitors with respect to the ORL1 receptor, the NOC (1 microM) current was depressed in amplitude by a putative NOC precursor product, nocistatin (1 microM; by 18+/-4%, n=6) and also by a non-peptidyl ORL1 receptor antagonist, CompB (1 microM; by 64+/-10%, n=7) without a change in holding currents. On the other hand, a putative ORL1 receptor antagonist, [Phe(1)psi(CH(2)-NH)Gly(2)]nociceptin-(1-13)-NH(2) (1 microM; which is a derivative of NOC), by itself induced an outward current (7+/-3 pA, n=8), during which the NOC current was suppressed in amplitude by 56+/-8% (n=8). We conclude that NOC activates in SG neurones a K(+) channel exhibiting a mild inwardly rectification through the activation of ORL1 receptor; this hyperpolarising action of NOC might contribute to at least a part of its antinociceptive effect.

[Examination on efficacy and safety of concurrent use of ondansetron hydrochloride and steroid in gynecological cancer patients on cisplatin].

The anti-emetic effect and safety in patients receiving ondansetron hydrochloride (OND group) and ondansetron and dexamethasone (DEX group) concurrently in cases of acute and delayed onset emesis induced by a single high dose of cisplatin, given as a chemotherapy to gynecological cancer patients, were comparatively studied. The study subjects were 139 gynecological cancer patients. The OND group received 4 mg of ondansetron via slow intravenous injection on Day 1, 30 minutes prior to cisplatin, and for Days 2 to 5, the subjects orally received 4 mg ondansetron tablet each day. The DEX group received the same dose regimen of ondansetron as the OND group for Days 1-5, but in addition the subjects received dexamethasone injection in doses of 8 mg twice daily on Day 1 and 4 mg (1 mg QID) daily for Days 2-5. An anti-emetic effect against acute nausea and vomiting was achieved in 47.9% of the OND group and in a higher rate of 84.2% of the DEX group. Significantly better efficacy was seen in the DEX group also in the complete suppression rate of nausea and vomiting and the improvement of food intake. The group also achieved better efficacy in delayed onset of emesis. Adverse reactions were observed in 2 cases (2 reports of headache) in the OND group and 5 cases (2 reports of hiccups, 2 headache, 2 diarrhea, one constipation, one hot facial flushes and one elevation of gamma-GTP) in the DEX group; however, since the symptoms were all mild, we did not consider there was any problem in safety. We conclude from the above findings that concurrent administration of ondansetron hydrochloride and dexamethasone is a clinically useful treatment for acute and delayed onset emesis induced by a single high dose of cisplatin given to gynecological cancer patients.

[Examination on efficacy and safety of concurrent use of ondansetron hydrochloride and steroid in lung cancer patients on cisplatin].

The anti-emetic effect and safety in patients receiving ondansetron hydrochloride (OND group) and concurrent use of ondansetron and dexamethasone (DEX group) in cases of acute and delayed onset emesis induced by a single high dose of cisplatin, given as a chemotherapy to lung cancer patients, were comparatively studied. The study subjects were 78 lung cancer patients. The OND group received 4 mg of ondansetron via slow intravenous injection on Day 1, 30 minutes prior to cisplatin, and for Days 2 to 5, the subjects orally received 4 mg ondansetron tablet each day. The DEX group received the same dose regimen of ondansetron as the OND group for Days 1-5, but in addition the subjects received dexamethasone injection in doses of 8 mg twice daily on Day 1 and 4 mg (1 mg QID) daily for Days 2-5. An anti-emetic effect against acute nausea and vomiting was achieved in 83.8% of the OND group and in a higher rate of 94.6% of the DEX group. Significantly better efficacy was seen in the DEX group as to the complete suppression rate of nausea and vomiting and the improvement of food intake. The group also achieved better efficacy in delayed onset of emesis. Two cases of adverse reactions (hiccups and elevation of ALT and BUN) were observed in the DEX group; however, since the symptoms were all mild, we did not consider there was any problem in safety. We conclude from the above findings that concurrent administration of ondansetron hydrochloride and dexamethasone is a clinically useful treatment for acute and delayed onset emesis induced by a single high dose of cisplatin given to lung cancer patients.

[Circulating cancer cells in the peripheral blood].

Occasional observations on this subject were seen until 1995 when Engell reported the large study on circulating cancer cells in the peripheral blood. Engell's report generated great enthusiasm in our country also. But, these cytologic method have a low sensitivity. Consequently, studies on the circulating tumor cells have been abandoned. However, since 1987, RT-PCR and other molecular biologic method were introduced for the identification of circulating cancer cells and micrometastases in bone marrow as well as in lymphnode. Serial analysis of a large number of patients by well-qualified laboratories have been performed. Several authors have shown a significant correlation between detection of cancer cells and relapse in some forms of malignancies. These research may be beneficial in the staging of cancer, in monitoring the effectiveness of cancer treatment, etc. Detection of cancer cells in the peripheral blood likely to have a profound impact on the practice of clinical oncology.

Voltage-clamp recordings of postsynaptic currents in substantia gelatinosa neurons in vitro and its applications to assess synaptic transmission.

We describe here procedures for recording postsynaptic currents in substantia gelatinosa neurons on a transverse spinal cord slice preparation with an attached dorsal root. At the holding potential of -70 mV, glutamatergic spontaneous excitatory postsynaptic currents (EPSCs) and dorsal root (A delta and/or C fiber) stimulation-evoked EPSCs could be observed. Whereas at the holding potential of 0 mV, spontaneous inhibitory postsynaptic currents (IPSCs) and dorsal root A delta fiber stimulation-evoked IPSCs could be encountered. The methods make it possible to evaluate synaptic transmission by analysing the postsynaptic currents on dorsal root attached spinal cord slice.

[Anti-nociceptive effect of calcitonin on chronic pain associated with osteoporosis].

Calcitonin is widely used clinically for alleviating hyperalgesia as well as recovering bone mass associated with osteoporosis. However, it's analgesic mechanism is not clear, although involvement of serotonergic system is suggested. We investigated a mechanism of calcitonin actions using ovariectomized rats which exhibit hyperalgesia. Whole-cell patch-clamp recording was employed to test an effect of calcitonin on synaptic transmission in the dorsal horn. In normal rats, transmitter release from fine myelinated Adelta and unmyelinated C afferents was depressed by serotonin, while the effect of 5-HT on C afferents was disappeared in OVX rats. This elimination of the 5-HT action was reversed by administration of calcitonin.

In vivo patch-clamp analysis of IPSCs evoked in rat substantia gelatinosa neurons by cutaneous mechanical stimulation.

To know a functional role of inhibitory synaptic responses in transmitting noxious and innoxious information from the periphery to the rat spinal dorsal horn, we examined inhibitory postsynaptic currents (IPSCs) elicited in substantia gelatinosa (SG) neurons by mechanical stimuli applied to the skin using the newly developed in vivo patch-clamp technique. In the majority (80%) of SG neurons examined, a brush stimulus applied to the ipsilateral hind limb produced a barrage of IPSCs that persisted during the stimulus, while a pinch stimulus evoked IPSCs only at its beginning and end. The pinch-evoked IPSCs may have been caused by a touch that occurs at the on/off time of the pinch. The evoked IPSCs were blocked by either a glycine-receptor antagonist, strychnine (4 microM), or a GABA(A)-receptor antagonist, bicuculline (20 microM). All SG neurons examined received inhibitory inputs from a wide area throughout the thigh and lower leg. When IPSCs were examined together with excitatory postsynaptic currents (EPSCs) in the same neurons, a brush evoked a persistent activity of both IPSCs and EPSCs during the stimulus while a pinch evoked such an activity of EPSCs but not IPSCs. It is suggested that innoxious mechanical stimuli activate a GABAergic or glycinergic circuitry in the spinal dorsal horn. This inhibitory transmission may play an important role in the modulation of noxious information in the SG.

Capsaicin induces a slow inward current which is not mediated by substance P in substantia gelatinosa neurons of the rat spinal cord.

Whole-cell voltage-clamp techniques were employed to investigate a capsaicin-induced current in substantia gelatinosa (SG) neurons in the dorsal horn of adult rat spinal cord slices. Bath-applied capsaicin (2 microM) for 30 s activated a slow excitatory current having an amplitude of 21.3+/-6.3 pA and a duration of 93+/-13 s (n=10; V(H)=-70 mV). This capsaicin current was compared in amplitude under various conditions among different SG neurons. After either neonatal capsaicin treatment or sciatic-nerve transection, by which C-afferent fibers are known to degenerate, this capsaicin current was reduced in amplitude to 5.0+/-3.5 pA (n=8) or 4.5+/-2.3 pA (n=6), respectively. A non-N-methyl-D-aspartate (NMDA)-receptor antagonist, CNQX (10 microM), depressed greatly the capsaicin current to 4.0+/-1.3 pA (n=9). On the other hand, this current had an amplitude of 14.4+/-2.7 pA (n=10) in the presence of an NMDA-receptor antagonist, AP-5 (50 microM); this value was not significantly different from that in the control (P>0.05). Substance P (SP; 1-2 microM) superfused for 2 min had no detectable effect on all SG neurons examined (n=7). After SP washout, however, these cells exhibited a capsaicin current (22.8+/-12.1 pA); this current persisted in the presence of a neurokinin-1 receptor antagonist, L-732,138 (1 microM; 19.8+/-3.5pA, n=9). The capsaicin current was not abolished by an intracellular dialysis with GDP-beta-S (1 mM; 20. 2+/-2.4 pA, n=9) which inhibited a baclofen (10 microM) response mediated by the G-protein-coupled GABA(B) receptor. These results indicate that the capsaicin-induced current is mediated through the activation of C-fibers by non-NMDA receptors. This mechanism in SG neurons is different from that known in neurons in other laminae of the dorsal horn that is thought to be a direct action of SP released from C-fibers. This current in SG neurons would contribute to the pain sensation caused by capsaicin.

Responsiveness of rat substantia gelatinosa neurones to mechanical but not thermal stimuli revealed by in vivo patch-clamp recording.

1. Synaptic responses of 46 substantia gelatinosa (SG) neurones in the spinal dorsal horn to cutaneous mechanical and/or thermal stimuli were investigated in an in vivo rat preparation with whole-cell patch-clamp recordings. The clamped neurones were identified as being in the SG based on either their morphological features by intrasomatic injection of biocytin or the depth of the neurones from the surface of the spinal cord. 2. In all SG neurones examined where spontaneous EPSCs occurred, pinch (noxious) and air (innocuous) stimuli applied to the ipsilateral hindlimb elicited a barrage of EPSCs (some of which initiated an action potential under current-clamp conditions), which subsided just after cessation of the stimuli without any residual slow current (or after-discharge). The spontaneous and evoked EPSCs were reversibly abolished by a non-N-methyl-D-aspartate (non-NMDA) receptor antagonist, CNQX (20 microM). 3. Noxious (>= 45 C) or innocuous (<= 40 C) thermal stimuli did not elicit any synaptic responses in all 18 SG neurones tested which were sensitive to mechanical stimuli. Noxious cold stimulation (<= 10 C) also failed to produce any responses (n = 6). 4. It is concluded that both noxious and innocuous mechanical information to SG neurones are transmitted primarily by activation of non-NMDA receptors, probably without any involvement of slow synaptic transmission, and that thermal information is conveyed to areas of the dorsal horn other than SG.

Effects of anti-emetic drug (tropisetron) on quality of life during chemotherapy: use of a diary-type questionnaire and application of summary measures for assessment in a randomized, multicentre study. Joint Research Group for Tropisetron Double-Blind Comparative Study.

The role of tropisetron as an anti-emetic drug in the prevention of delayed nausea and vomiting remains unclear. Therefore, effectiveness of tropisetron in patients receiving cancer chemotherapy was evaluated by application of summary measures using a quality of life (QOL) questionnaire. The diary-type QOL self-rating questionnaire was constituted by seven scales. A double-blind randomized, multicentre study was performed in 33 hospitals. Quality of life was measured in 98 patients. Patients receiving cisplatin were randomized to group T (administration of tropisetron before and 4 days after cisplatin treatment) and group P (administration of tropisetron before cisplatin treatment and followed by placebo for 4 days). The rate of complete protection from delayed emesis in the groups T and P was 46.3 and 36.5%. All scales, except social wellbeing changed immediately in both groups and reached a nadir on days 2-3, after that returning to the control levels during 2 weeks after cisplatin treatment. Group T was significantly better than group P in physical wellbeing, mental wellbeing, functional wellbeing and global QOL scores summarized by area under the curve and Difmax (maximum differences of QOL scales' score from the best score throughout the entire period). These results indicate that continuous administration of tropisetron could contribute to preventing patient QOL influenced by cisplatin treatment, and the combined use of summary measures may be useful for the evaluation of QOL in cancer clinical trial.

[Cancer of the liver, pancreas, gallbladder, and bile duct].

In cancer of the liver, pancreas, gallbladder, and bile duct, symptoms and signs are non-specific compared with benign conditions. Early detection is difficult and long term survivors are extremely low. The role of systemic chemotherapy in patients with these malignancies is only palliative. Prolongation of survival has not been demonstrated with any single agent or with any combination chemotherapy. However, in some instances, useful symptomatic palliation may occur even without an objective partial response. Quality of life is an important parallel endpoint in these malignancies. In advanced cancer of the liver, numerous alternative therapies have been investigated. These include pharmacologically based chemotherapeutic delivery methods, percutaneous alcohol injection, TAE, TACE, etc. However, further rigorous investigations will be warranted. It is hoped that successful chemotherapeutic agents or other modalities can be developed and combined with limited efficacy of surgery and radiotherapy. In this respect, newer, more active chemotherapy regimens are clearly needed.

Action of capsaicin on dorsal root-evoked synaptic transmission to substantia gelatinosa neurons in adult rat spinal cord slices.

An action of capsaicin was investigated on dorsal root-evoked synaptic transmission to substantia gelatinosa (SG) neurons in adult rat spinal cord slices by use of the whole-cell voltage-clamp technique. In 79% of neurons examined, superfusing capsaicin (1 microM) for 30 s depressed a C-fiber-evoked excitatory synaptic current in a manner sensitive to a capsaicin-receptor antagonist, capsazepine (10 microM). On the contrary, Adelta-fiber-evoked excitatory and inhibitory synaptic currents were unaffected by capsaicin in all of cells tested. It is concluded that capsaicin specifically acts on C-afferents, resulting in an inhibition of evoked excitatory transmission to the SG; this may contribute to, at least in part, an acute analgesic action of capsaicin.

[Combination chemotherapy--present status and problems].

Principles for the development of effective clinical combination chemotherapy has been recognized for many years, and many trials have been continue to be used in the design of more effective combinations. Drugs to be used in the combination chemotherapy regimen are as follows: 1) Only those drugs proven effective should be combined, 2) Each drugs have a different mechanism of action, 3) Each drug have a different spectrum of toxicities, 4) Each drugs should be administered at their adequate dose intensity and schedule. Optimally, all agents would be administered simultaneously, but they can be administered in alternating sequence. However, the available results have not provided definitive evidence for the development of adequate, effective combination chemotherapy. Prospective randomized comparisons will eventually elucidate the better regimens. Further studies are warranted.