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Biomedical subjects

Y Katayama

Publications and source records attributed to Y Katayama.

At least 271 records · Page 15Linked to original sources
PubMed1998

Cloning and sequencing of the Sphingomonas (Pseudomonas) paucimobilis gene essential for the O demethylation of vanillate and syringate.

Sphingomonas (Pseudomonas) paucimobilis SYK-6 is able to grow on 5,5'-dehydrodivanillic acid (DDVA), syringate, vanillate, and other dimeric model compounds of lignin as a sole carbon source. Nitrosoguanidine mutagenesis of S. paucimobilis SYK-6 was performed, and two mutants with altered DDVA degradation pathways were isolated. The mutant strain NT-1 could not degrade DDVA, but could degrade syringate, vanillate, and 2,2',3'-trihydroxy-3-methoxy-5,5'-dicarboxybiphenyl (OH-DDVA). Strain DC-49 could slowly assimilate DDVA, but could degrade neither vanillate nor syringate, although it could degrade protocatechuate and 3-O-methylgallate. A complementing DNA fragment of strain DC-49 was isolated from the cosmid library of strain SYK-6. The minimum DNA fragment complementing DC-49 was determined to be the 1.8-kbp insert of pKEX2.0. Sequencing analysis showed an open reading frame of 1,671 bp in this fragment, and a similarity search indicated that the deduced amino acid sequence of this open reading frame had significant similarity (60%) to the formyltetrahydrofolate synthetase of Clostridium thermoaceticum.

Amino Acid Sequence↗
PubMed1998

Cloning of a Sphingomonas paucimobilis SYK-6 gene encoding a novel oxygenase that cleaves lignin-related biphenyl and characterization of the enzyme.

Sphingomonas paucimobilis SYK-6 transforms 2,2'-dihydroxy-3,3'-dimethoxy-5,5'-dicarboxybiphenyl (DDVA), a lignin-related biphenyl compound, to 5-carboxyvanillic acid via 2,2',3-trihydroxy-3'-methoxy-5,5'-dicarboxybiphenyl (OH-DDVA) as an intermediate (15). The ring fission of OH-DDVA is an essential step in the DDVA degradative pathway. A 15-kb EcoRI fragment isolated from the cosmid library complemented the growth deficiency of a mutant on OH-DDVA. Subcloning and deletion analysis showed that a 1.4-kb DNA fragment included the gene responsible for the ring fission of OH-DDVA. An open reading frame encoding 334 amino acids was identified and designated ligZ. The deduced amino acid sequence of LigZ had 18 to 21% identity with the class III extradiol dioxygenase family, including the beta subunit (LigB) of protocatechuate 4,5-dioxygenase of SYK-6 (Y. Noda, S. Nishikawa, K.-I. Shiozuka, H. Kadokura, H. Nakajima, K. Yano, Y. Katayama, N. Morohoshi, T. Haraguchi, and M. Yamasaki, J. Bacteriol. 172:2704-2709, 1990), catechol 2,3-dioxygenase I (MpcI) of Alcaligenes eutrophus JMP222 (M. Kabisch and P. Fortnagel, Nucleic Acids Res. 18:3405-3406, 1990), the catalytic subunit of the meta-cleavage enzyme (CarBb) for 2'-aminobiphenyl-2,3-diol from Pseudomonas sp. strain CA10 (S. I. Sato, N. Ouchiyama, T. Kimura, H. Nojiri, H. Yamane, and T. Omori, J. Bacteriol. 179:4841-4849, 1997), and 2,3-dihydroxyphenylpropionate 1,2-dioxygenase (MhpB) of Escherichia coli (E. L. Spence, M. Kawamukai, J. Sanvoisin, H. Braven, and T. D. H. Bugg, J. Bacteriol. 178:5249-5256, 1996). The ring fission product formed from OH-DDVA by LigZ developed a yellow color with an absorption maximum at 455 nm, suggesting meta cleavage. Thus, LigZ was concluded to be a ring cleavage extradiol dioxygenase. LigZ activity was detected only for OH-DDVA and 2,2',3,3'-tetrahydroxy-5,5'-dicarboxybiphenyl and was dependent on the ferrous ion.

Amino Acid Sequence↗
PubMed1998

Cloning of genes coding for the three subunits of thiocyanate hydrolase of Thiobacillus thioparus THI 115 and their evolutionary relationships to nitrile hydratase.

Thiocyanate hydrolase is a newly found enzyme from Thiobacillus thioparus THI 115 that converts thiocyanate to carbonyl sulfide and ammonia (Y. Katayama, Y. Narahara, Y. Inoue, F. Amano, T. Kanagawa, and H. Kuraishi, J. Biol. Chem. 267:9170-9175, 1992). We have cloned and sequenced the scn genes that encode the three subunits of the enzyme. The scnB, scnA, and scnC genes, arrayed in this order, contained open reading frames encoding sequences of 157, 126, and 243 amino acid residues, respectively, for the beta, alpha, and gamma subunits, respectively. Each open reading frame was preceded by a typical Shine-Dalgarno sequence. The deduced amino-terminal peptide sequences for the three subunits were in fair agreement with the chemically determined sequences. The protein molecular mass calculated for each subunit was compatible with that determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. From a computer analysis, thiocyanate hydrolase showed significant homologies to bacterial nitrile hydratases known to convert nitrile to the corresponding amide, which is further hydrolyzed by amidase to form acid and ammonia. The two enzymes were homologous over regions corresponding to almost the entire coding regions of the genes: the beta and alpha subunits of thiocyanate hydrolase were homologous to the amino- and carboxyl-terminal halves of the beta subunit of nitrile hydratase, and the gamma subunit of thiocyanate hydrolase was homologous to the alpha subunit of nitrile hydratase. Comparisons of the catalytic properties of the two homologous enzymes support the model for the reaction steps of thiocyanate hydrolase that was previously presented on the basis of biochemical analyses.

Amino Acid Sequence↗
PubMed1998

Detection of measles virus mRNA from autopsied human tissues.

By reverse transcription-PCR, measles virus (MV) mRNA was detected in the brain, kidney, spleen, liver, and lung tissues obtained from 23 (45.1%) of 51 autopsy subjects, with the detection rates of each tissue ranging from 8 to 20%. Sequence analysis revealed frequent mutations in the corresponding viral protein. These results suggest that MV mutants commonly persist in apparently healthy individuals.

Adolescent↗
PubMed1998

Characteristics of rabbit ClC-2 current expressed in Xenopus oocytes and its contribution to volume regulation.

In the Xenopus oocyte heterologous expression system, the electrophysiological characteristics of rabbit ClC-2 current and its contribution to volume regulation were examined. Expressed currents on oocytes were recorded with a two-electrode voltage-clamp technique. Oocyte volume was assessed by taking pictures of oocytes with a magnification of x 40. Rabbit ClC-2 currents exhibited inward rectification and had a halide anion permeability sequence of Cl- > or = Br- >> I- > or = F-. ClC-2 currents were inhibited by 5-nitro-2-(3-phenylpropylamino)benzoic acid (NPPB), diphenylamine-2-carboxylic acid (DPC), and anthracene-9-carboxylic acid (9-AC), with a potency order of NPPB > DPC = 9-AC, but were resistant to stilbene disulfonates. These characteristics are similar to those of rat ClC-2, suggesting rabbit ClC-2 as a counterpart of rat ClC-2. During a 30-min perfusion with hyposmolar solution, current amplitude at -160 mV and oocyte diameter were compared among three groups: oocytes injected with distilled water, oocytes injected with ClC-2 cRNA, and oocytes injected with ClC-2 delta NT cRNA (an open channel mutant with NH2-terminal truncation). Maximum inward current was largest in ClC-2 delta NT-injected oocytes (-5.9 +/- 0.4 microA), followed by ClC-2-injected oocytes (-4.3 +/- 0.6 microA), and smallest in water-injected oocytes (-0.2 +/- 0.2 microA), whereas the order of increase in oocyte diameter was as follows: water-injected oocytes (9.0 +/- 0.2%) > ClC-2-injected oocytes (5.3 +/- 0.5%) > ClC-2 delta NT-injected oocytes (1.1 +/- 0.2%). The findings that oocyte swelling was smallest in oocytes with the largest expressed currents suggest that ClC-2 currents expressed in Xenopus oocytes appear to act for volume regulation when exposed to a hyposmolar environment.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1998

[Usefulness of magnetite as an MRI contrasting agent in an experimental cerebral ischemic model evaluation of injecting time point].

The superacute stage of focal ischemia can be visualized using T2-weighted MRI following the injection of superparamagnetic iron oxide particles (magnetite). In this study we evaluated the optimal time point, i.e. the time producing the strongest signal, for the injection of magnetite using T2-weighted MRI following left parmanent middle cerebral artery occlusion (lt.-PMCAO). Male Sprague-Dawley rats were anesthetized and the left middle cerebral artery (lt.-MCA) was permanently occluded. Magnetite was then injected into the femoral vein after 20 to 30 min of lt.-PMCAO. T2-weighted MR images were taken immediately, and 15 and 30 min after magnetite injection. A high signal area at the region of the lt.-MCA was clearly seen on the T2-weighted MRI immediately after magnetite injection. However, it became less clear after 15 min, and by 30 min could not be distinguished. These results suggest that magnetite should be injected immediately prior to T2-weighted MR imaging during the superacute stage of focal ischemia.

Animals↗
PubMed1998

[An evaluation of ischemic stroke using dynamic contrast enhanced perfusion MRI].

Thrombolytic therapy during the hyperacute stage is important for salvaging dying cerebral tissue. To date, however, accurate non-invasive assessment of an ischemic lesion during the hyperacute stage has not been possible. Perfusion MRI may be the key to the quick diagnosis of ischemic lesions. To assess the feasibility of dynamic contrast enhanced perfusion MRI, echo planar imaging was performed in 10 patients with ischemic stroke. The relative cerebral blood volume (rCBV), mean transit time (MTT), and relative cerebral blood flow(rCBF) were measured based on moment analysis and the gamma variate method. These measurements, however, are not suitable for the detection of cerebral ischemia during the hyperacute stage. Therefore, we additionally studied the changes in a concentration curve (time-delta R* curve) of Gd-DTPA, injected into the median vein of the forearm. From the curve the SUM (delta R*) time to peak and the delta R* peak, which may be calculated quickly, were determined and were compared to rCBV, MTT, and rCBF, respectively. The rCBV and the rCBF in the ischemic regions were less than those in the contralateral healthy regions (p < 0.05), and the MTT in the ischemic regions was longer than that in the contralateral healthy regions (p < 0.05). Additionally, SUM (delta R*) and the delta R* peak in the ischemic regions were less, and the time to peak in the ischemic regions was longer than the value in the contralateral healthy regions (p < 0.05), correlating well to the rCBV, rCBF, and MTT measurements. Also, images of these parameters, depicting the ischemic lesion earlier than conventional T2 weighted images, can be easily made by using an MRI console. These results suggest that the SUM (delta R*), time to peak and the delta R* peak images calculated with dynamic contrast enhanced perfusion MRI may be one of the best techniques for the detection of cerebral ischemic lesions during the hyperacute stage.

Acute Disease↗
PubMed1998

[Usefulness of magnetite as an MRI contrasting agent in an experimental cerebral ischemic model. Evaluation of lesion detecting time].

Gd-DTPA has a T1 shortening effect that enhances the contrast in MRI and is widely used for the clinical evaluation of CNS diseases, though it is not suitable for the detection of cerebral ischemic regions during the superacute stage. Superparamagnetic iron oxide particles have a T2 shortening effect on relaxation time, reducing signal intensity on T2-weighted MRI in normal cerebral tissue. From this perspective we tested the feasibility of detecting ischemic lesions during the superacute stage using superparamagnetic iron oxide particles-enhanced MRI. Male Sprague-Dawley rats were anesthetized using pentobarbital and the left middle cerebral artery was permanently occluded (lt.-PMCAO) using a modified version of the Koizumi method. After lt.-PMCAO, 100 mumoles Fe/kg, 1 ml/kg magnetite, superparamagnetic iron oxide particles, (magnetite-injected group, n = 9) or physiological saline (vehicle-injected group, n = 9) was injected into the femoral vein. T2-weighted MR images were performed at designated time points immediately after injection of magnetite or vehicle on a 6.34 T MR unit. Additionally, in separate animals coronal sections of the brain were stained with 4% 2, 3, 5 triphenyl-tetrazolium-chloride (TTC) to confirm the infarct region. In the magnetite-injected group, a high signal area at the region of lt.-MCA was visible within-20 to 30 min following lt.-PMCAO, whereas in the vehicle-injected group no high signal ischemic area could be confirmed until 3 h after lt.-PMCAO. Infarction was noticed in the TTC staining 3 h following lt.-PMCAO. In this study magnetite injection allowed the detection of ischemia in the occluded MCA area on T2-weighted MRI during the superacute stage. These results suggest that ischemia during the superacute stage can be evaluated using magnetite enhanced MRI.

Animals↗
PubMed1998

[White matter changes of corpus callosum in normotensive and hypertensive rats following bilateral carotid artery stenosis].

The pathological mechanism responsible for cerebral white matter lesions, frequently observed in elderly individuals, is supposed to be chronic cerebral hypoperfusion Vascular risk factors such as hypertension and carotid artery stenosis are usually involved in these lesions. The objective of this study was to elucidate the role of hypertension in white matter changes using a bilateral carotid artery stenosis model. To induce cerebral hypoperfusion, chronic stenosis was produced by placing a 3 mm long polyethylene cuff around the bilateral carotid arteries of normotensive Wistar rats (Wistar) and spontaneously hypertensive rats (SHR). Two different diameters of tube, PE-50 (inside diameter 0.58 mm) and PE-60 (inside 0.76 mm), were used to induce different degrees of stenosis. The rats were divided into three groups, sham group, PE-50 group, and PE-60 group (each group included 15 Wistar and 15 SHR). At 1,2, and 4 weeks after the operation, pathological changes in which matter were observed in the corpus callosum, and the degree of lesions was assessed using the Vacuole Index. PaO2, PaCO2, pH and mean arterial blood pressure (MABP) were measured prior to and immediately after carotid stenosis. MABP in SHR was significantly higher than in Wistar in all groups (p < 0.05). Other physiological data did not differ significantly between Wistar and SHR. There was no difference in white matter changes between the Wistar sham and SHR sham groups at any time point. There was only a small degree of white matter lesions in the Wistar PE-50 and -60 groups after 4 weeks stenosis, and they did not differ significantly from the sham. In both the SHR PE-50 and -60 groups, however, white matter lesions were slightly apparent at 1 week, and were clearly visible at 4 weeks. The degree of lesions in the SHR PE-50 was significantly higher at 1 week than in the sham (p < 0.01), and both the sham and the Wistar PE-50 at 2 and 4 weeks (p < 0.01), and the SHR PE-60 at 4 weeks (p < 0.01). The SHR PE-60 also had significantly more lesions than the sham at 2 weeks (p < 0.05), and both the sham and the Wistar PE-60 at 4 weeks (p < 0.01). These findings indicate that both hypertension and chronic hypoperfusion play important roles in the development of white matter lesions.

Animals↗
PubMed1998

The mouse mammary tumor cell line, MMT060562, produces prostaglandin E2 and leukemia inhibitory factor and supports osteoclast formation in vitro via a stromal cell-dependent pathway.

Osteoclastic bone resorption increases at the site of bone metastasis, but little is known about how tumor cells induce osteoclast (OC) recruitment in the bone marrow microenvironment. To clarify this point, we examined the effects of various mouse tumor cells on OC recruitment using cocultures of tumor cells and mouse marrow cells. The mouse mammary tumor cell lines, MMT060562 (MMT), BALB/c-MC, Jyg-MC(A), or other nonmammary tumor cell lines, LLC and B16, were cocultured with mouse marrow cells, and OC recruitment from marrow cells was determined by counting the number of tartrate-resistant acid phosphatase-positive multinucleated cells (TRAP(+) MNCs) formed. Of the tumor cells examined, MMT and BALB/c-MC stimulated OC formation, but other tumor cells did not. OC formation with MMT was dependent on the number of MMTs inoculated, and only ten cells per well were sufficient to induce OC development. OCs appeared on day 4, and the number reached a maximum on days 5-8 and decreased thereafter. TRAP(+) MNCs induced by MMT satisfied the major criteria of OCs, such as the presence of calcitonin receptors and the ability to resorb calcified tissues. The majority of OCs were formed adjacent to the stromal cells, which were positive for alkaline phosphatase. When spleen cells were cocultured with MMT, no OCs were formed. In contrast, when osteoblastic cells were added to cocultures of spleen cells and MMT, many OCs were formed. The cultured media (CM) of MMT induced OC formation in mouse marrow cultures. Neither parathyroid hormone-like nor interleukin 1-like activity was present in the CM. MMT constitutively produced prostaglandin E2 (PGE2) and OC formation in cocultures was completely inhibited by indomethacin. Fractionation of the CM of MMT by ultrafiltration indicated that the OC-inducing activities were present not only in the fraction with molecular weight below 3 kDa but also in the fraction with molecular weight above 3 kDa. OC-inducing activity with high molecular weight was eluted around 50 kDa by Bio-Gel P-60 column chromatography. The active fractions also possessed leukemia inhibitory factor (LIF) activity, and OC-inducing activity of the peak fraction was inhibited in the presence of anti-LIF neutralizing antibody. The results of this study indicated that MMTs release PGE2 and LIF, which in turn stimulate OC formation via a stromal cell-dependent pathway. These culture systems will help to clarify the mechanisms by which tumor cells induce OC formation in a bone marrow microenvironment.

Acid Phosphatase↗
PubMed1998

Chinese hamster ovary cells expressing alpha4beta1 integrin stimulate osteoclast formation in vitro.

It is reported that Chinese hamster ovary cells transfected with human alpha4 cDNA (alpha4CHOs) and expressing functional alpha4beta1 integrin developed bone metasasis in nude mice. To clarify the role of alpha4beta1 integrin in bone metastasis, in terms of tumor-mediated bone destruction, we examined whether alpha4CHOs stimulate osteoclast formation in cocultures with mouse bone marrow cells. The number of osteoclast-like cells identified as tartrate-resistant acid phosphatase positive multinucleated cells (TRAP(+) MNCs) formed from bone marrow cells increased with the increasing number of alpha4CHOs cocultured. The effects of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) and prostaglandin E2 (PGE2) on TRAP(+) MNC formation were enhanced in cocultures with alpha4CHOs. TRAP(+) MNCs induced by alpha4CHOs possessed calcitonin receptors and resorbed calcified tissues. In cocultures, alpha4CHOs and bone marrow stromal cells were in contact with each other and bone marrow stromal cells expressed vascular cell adhesion molecule-1 (VCAM-1), which is one of the ligands for alpha4beta1 integrin. TRAP(+) MNC formation was not stimulated in cocultures where direct contact between alpha4CHOs and bone marrow cells was inhibited by membrane filters. Alpha4CHOs do not support TRAP(+) MNC formation in cocultures with spleen cells but do support TRAP(+) mononuclear cell and MNC formation from spleen cells in the presence of osteoblastic cells. Cultured media from alpha4CHOs, bone marrow cells, and cocultures of alpha4CHOs and bone marrow cells did not stimulate TRAP(+) MNC formation or enhance the effects of 1,25(OH)2D3 and PGE2 in bone marrow cultures. The concentrations of PGE2 and interleukin-6 (IL-6) in cultured media were not different between the cultures of bone marrow cells and the cocultures of bone marrow cells and alpha4CHOs. Anti-human alpha4 and anti-mouse VCAM-1 antibodies inhibited TRAP(+) MNC formation induced by alpha4CHOs. These results indicate that alpha4CHOs stimulated TRAP(+) MNC formation through direct cell-to-cell interaction between alpha4beta1 and VCAM-1. It is suggested that in addition to various soluble factors regulating osteoclast formation, cell-to-cell interaction between tumor cells and bone marrow cells is important for inducing osteoclasts at the site of bone metastasis and leading to bone destruction.

Acid Phosphatase↗
PubMed1998

Type I collagen influence on gene expression in UMR106-06 osteoblast-like cells is inhibited by genistein.

We have previously shown that an exogenous type I collagen matrix can regulate expression of mRNA for parathyroid hormone (PTH)-related protein (PTHrP) and its receptor, the PTH/PTHrP receptor, in the UMR106-06 osteogenic sarcoma cell line, which is considered to be representative of a relatively mature osteoblast phenotype. Consistent with those data, we show here that growth of UMR106-06 cells on type I collagen increased PTH/PTHrP receptor-binding capacity. Analysis of the binding data showed that the number of PTH/PTHrP receptors expressed by cells cultured on collagen was at least 2-fold greater than that of cells cultured on plastic. Expression of mRNA encoding alkaline phosphatase (ALP) and osteopontin (OP) was also upregulated in cells cultured on collagen, suggesting that interaction with collagen promotes the osteoblast phenotype in this cell line. Retinoic acid (RA), which has also been shown to promote osteoblastic differentiation, synergized with type I collagen to cause super-induction of OP mRNA. In contrast, RA abolished the collagen-induced increase in ALP mRNA and PTH/PTHrP receptor mRNA. The collagen-mediated increase in the expression of OP and PTH/PTHrP receptor mRNA, but not that of ALP, was perturbed by prior covalent modification of the collagen by non-enzymatic glycation. The collagen effects did not occur via interaction with RGD amino acid domains in type I collagen, but evidence was obtained for involvement of the DGEA amino acid cell-binding domain. The mechanism by which plating of UMR106-06 cells on a type I collagen substrate affects PTH/PTHrP receptor mRNA levels was investigated. Inhibition of cytoskeletal organization using cytochalasin D, and inhibitors of protein phosphatases, protein kinase C, phospholipase C and cyclooxygenase, did not abrogate the collagen-mediated effects. In contrast, treatment of cells with the protein tyrosine kinase inhibitor genistein, but not herbimycin A, dose-dependently abolished the collagen effects on the expression of PTH/PTHrP receptor, ALP and OP mRNA. These results show that a type I collagen substrate influences the expression of osteoblast-associated genes in a cell model of mature osteoblasts and suggests that this involves, at least in part, changes in intracellular tyrosine phosphorylation.

Alkaline Phosphatase↗
PubMed1998

Three-dimensional anisotropy contrast (3DAC) magnetic resonance imaging of the human brain: application to assess Wallerian degeneration.

Three-dimensional anisotropy contrast (3DAC) magnetic resonance imaging is a new algorithm for the treatment of apparent diffusion tensor using the three primary colors. To determine if 3DAC has a clinical application for human brain, six normal volunteers and twenty patients with supratentorial cerebrovascular accidents were examined using clinical magnetic resonance imaging (MRI), and the changes in the 3DAC images associated with Wallerian degeneration of the pyramidal tract were evaluated. The 3DAC images exhibited impressive anatomical resolution. In all chronic stage patients with hemiparesis, the colors in the pyramidal tract were faded. Patients examined during the acute stage who later recovered from hemiparesis had no visible changes of the 3DAC image, whereas patients who recovered poorly showed distinct color fading in the pyramidal tract within 14 days following stroke. In conclusion, very fine anatomical structures are visible on 3DAC images, and it can be used as a diagnostic tool for the human brain.

Aged↗
PubMed1998

Multiple choroid plexus papillomas of the lateral ventricle distinct from villous hypertrophy. Case report.

Except for villous hypertrophy of the choroid plexus that may not be true tumors, multiple choroid plexus papillomas are extremely rare. The authors report a case involving multiple choroid plexus papillomas that were distinct from villous hypertrophy. These lesions were localized, one in the atrium of the right lateral ventricle and the other in the inferior horn of the left lateral ventricle. A review of the literature revealed that this case represented the first reported case of true multiple choroid plexus papillomas documented by findings on magnetic resonance imaging.

Adolescent↗
PubMed1998

Poststroke pain control by chronic motor cortex stimulation: neurological characteristics predicting a favorable response.

OBJECT: The goal of this study was to identify the neurological characteristics of patients with poststroke pain who show a favorable response to motor cortex (MC) stimulation used to control their pain. METHODS: The neurological characteristics of 31 patients treated by MC stimulation were analyzed. In 15 patients (48%), excellent or good pain control (pain reduction > 60%) was achieved for follow-up periods of more than 2 years by using MC stimulation at intensities below the threshold for muscle contraction. Satisfactory pain control was achieved in 13 (73%) of 18 patients in whom motor weakness in the painful area was virtually absent or mild, but in only two (15%) of the 13 patients who demonstrated moderate or severe weakness in the painful area (p < 0.01). Muscle contraction was inducible in the painful area in 20 patients when stimulated at a higher intensity. No such muscle response was inducible in the remaining 11 patients, no matter how extensively the authors attempted to determine appropriate stimulation sites. Satisfactory pain control was achieved in 14 (70%) of the 20 patients in whom muscle contraction was inducible, but in only one (9%) of the 11 patients in whom muscle contraction was not inducible (p < 0.01). No significant relationship was observed between pain control and various sensory symptoms, including the presence of hypesthesia, spontaneous dysesthesia, hyperpathia, and allodynia, or the disappearance of the N20 component of the median nerve-evoked somatosensory scalp potential. No significant relationship existed between the effect of MC stimulation on the pain and stimulation-induced phenomena, including paresthesia, improvement in motor performance, and attenuation of involuntary movements. CONCLUSION: These findings suggest that the pain control afforded by MC stimulation requires neuronal circuits that are maintained by the presence of intact corticospinal tract neurons originating from the MC. Preoperative evaluation of motor weakness of the painful area appears to be useful for predicting a favorable response to MC stimulation in the control of poststroke pain.

Cerebrovascular Disorders↗
PubMed1998

[Combination chemotherapy with cis-platinum and ifosfamide for hormone unresponsive prostate cancer].

PURPOSE: There is no effective therapy against hormone refractory prostate cancer. This led us to evaluate the effectiveness and toxicity of cis-platinum (CDDP) and ifosfamide (IFM) combination chemotherapy in the patients with hormone-unresponsive carcinoma of the prostate. METHODS: Patients with hormone-unresponsive prostate cancer were scheduled to receive CDDP 70 mg/m2 intravenously on day 1 and IFM 1.2 g/m2/day intravenously on day 1 through day 5 of 28-day cycle. RESULTS: Twenty seven patients with hormone unresponsive prostate cancer were enrolled onto this trial. Of these patients, seven (26%) demonstrated a partial objective response (PR), and ten (37%) a stable disease (ST). The response duration of PR cases lasted from 6 to 49 months with a median of 16 months and the response duration of PR + ST cases lasted from 3 to 36 months with a median of 10 months. Subjective improvement was obtained in 11 patients (41%). Survival duration of all cases were 4 to 89 months with a median of 23 months and probabilities of survival at 3 years and 5 years were 36% and 24%, respectively. The toxicity of this treatment was mostly mild to moderate, anemia (96%), leukocytopenia (89%), anorexia (81%), alopecia (67%), thrombocytopenia (44%), hematuria (38%), renal dysfunction (19%) and liver dysfunction (7%) were noticed. Severe toxicity was observed in two cases, one acute renal failure and one endotoxin shock. CONCLUSION: We conclude that CDDP and IFM combination chemotherapy was active regimen for hormone unresponsive prostate cancer.

Aged↗