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Biomedical subjects

M Koh

Publications and source records attributed to M Koh.

At least 19 recordsLinked to original sources

The effect of a fast bowling harness in cricket: an intervention study.

The influence of a bowling harness, as a training aid, was assessed as a means of modifying bowling technique. Thirty-three 13-year-old bowlers received a standardized 15 min of bowling coaching twice a week for 8 weeks. They were randomly assigned to one of two groups. The 13 participants in the intervention group used the bowling harness throughout the coaching, while also receiving verbal and visual feedback. The 20 participants in the non-harness group received the same visual and verbal feedback. Three-dimensional videography (200 Hz) of each player's bowling action enabled the calculation of transverse plane shoulder alignment counter-rotation, separation angle, lateral flexion and hyperextension of the trunk before and after the intervention. The restriction applied by the harness produced a significant reduction (P= 0.006) in separation angle and forced the bowler to adopt a position at back-foot impact that reduced the 'twist' in the spine. However, it had no effect on restricting other aspects of trunk movement during the critical phases of the bowling action. No significant long-term modifications to technique were found after the coaching intervention when players were assessed without the harness.

Adolescent↗

[A case of collecting duct carcinoma (Bellini duct carcinoma) producing carcinoembryonic antigen].

We report a case of collecting duct carcinoma (Bellini duct carcinoma) producing carcinoembryonic antigen (CEA). A 61-year-old man visited our hospital because of a left renal mass detected by ultrasonography in an other hospital. Computed tomography showed a low density tumor measuring about 3 cm in the left kidney. Angiography demonstrated a hypovascular tumor. The serum level of CEA was increased to 20 ng/ml. (normal < 7 ng/ml). Left radical nephrectomy was performed. Histological examination revealed collecting duct carcinoma with papillary growth (T1aN1M0). Cancer cells showed a positive immunohistochemical staining for CEA. Under a diagnosis of CEA-producing collecting duct carcinoma of the left kidney, the patient underwent systemic chemotherapy (M-VAC). The serum level of CEA decreased to the normal level after the nephrectomy, but six months postoperatively, metastatic bone tumor at the left pelvic bone was revealed on the plain film and at the same time, the CEA level was increased again.

Antineoplastic Combined Chemotherapy Protocols↗

Safety of discontinuation of anticoagulation in patients with intracranial hemorrhage at high thromboembolic risk.

BACKGROUND: Limited data are available to guide the management of anticoagulation in patients with intracranial hemorrhage (ICH) at high thromboembolic risk. OBJECTIVE: To review the management of anticoagulation in patients with ICH at high thromboembolic risk. PATIENTS AND METHODS: We reviewed the management of anticoagulation in 141 patients who have a high risk of ischemic stroke and have ICH while taking warfarin. The 30-day risk of ischemic stroke while not taking anticoagulation treatment was determined using Kaplan-Meier survival estimates. RESULTS: The indications for anticoagulation were a prosthetic heart valve (52 patients [group 1]), atrial fibrillation and cardioembolic stroke (53 patients [group 2]), and a recurrent transient ischemic attack or an ischemic stroke (36 patients [group 3]). A prior ischemic stroke occurred in 14 (27%) of group 1 patients and in 23 (43%) of group 2 patients. Death occurred in 43% of the 141 patients. The median time not taking warfarin in this cohort was 10 days. Three patients had an ischemic stroke within 30 days of warfarin therapy discontinuation. Using Kaplan-Meier survival estimates, the probability of having an ischemic stroke at 30 days following warfarin therapy cessation in groups 1, 2, and 3 was 2.9% (95% confidence interval, 0%-8.0%), 2.6% (95% confidence interval, 0%-7.6%), and 4.8% (95% confidence interval, 0%-13.6%), respectively. In the 35 patients who had warfarin therapy restarted, none had recurrence of ICH during the same hospitalization. CONCLUSIONS: Discontinuation of warfarin therapy for 1 to 2 weeks has a comparatively low probability of embolic events in patients at high embolic risk. This should be taken into consideration when deciding whether to continue or discontinue anticoagulation in these patients at high embolic risk. Early recurrence of ICH is exceedingly uncommon.

Adult↗

Hydrocephalus is a determinant of early mortality in putaminal hemorrhage.

BACKGROUND AND PURPOSE: Previous studies have shown that the volume of intracerebral hemorrhage and Glasgow Coma Score (GCS) on admission are powerful predictors of 30-day mortality. However, the significance of hydrocephalus associated with deep cerebral hemorrhage has not been studied extensively. The purpose of this study was to determine the prognostic indicators of 30-day mortality in patients with deep cerebral hemorrhage. METHODS: We studied 100 consecutive patients with deep cerebral hemorrhage between 1994 and 1998. Deep cerebral hemorrhage was divided into 2 groups: putaminal hemorrhage (lateral group) and thalamic and caudate hemorrhage (medial group). Univariate and multivariate logistic regression analyses were performed to determine independent prognostic indicators of 30-day mortality. RESULTS: Hydrocephalus was present in 40 of the 100 patients. The 30-day mortality was 29%, and hydrocephalus was present in 76% of those who died. Multivariate analyses showed 2 independent prognostic indicators of 30-day mortality for putaminal hemorrhage: GCS </=8 (P:=0.002, odds ratio [OR] 37.7, CI 3.6 to 396.9) and hydrocephalus (P:=0.005, OR 27.4, CI 2.7 to 282.6). However, only GCS </=8 (P:=0.0002, OR 16.5, CI 3.7 to 73.4) was predictive of 30-day mortality for thalamic and caudate hemorrhage. This model (GCS </=8 and hydrocephalus) has a sensitivity of 57% and a specificity of 91% for predicting 30-day mortality for putaminal hemorrhage. When both attributes were present in putaminal hemorrhage (GCS </=8 and hydrocephalus), 1 (11%) of 9 patients survived, and when both attributes were missing 28 (100%) of 28 patients survived. CONCLUSIONS: Obstructive hydrocephalus on admission in a comatose patient with a putaminal hemorrhage predicts 30-day mortality.

Adult↗

Use of Bacillus brevis for synthesis and secretion of Des-B30 single-chain human insulin precursor.

A synthetic gene encoding a single chain human insulin precursor [B-chain (1-29)-A-chain] linked to the C-terminal lysine of human epidermal growth factor (1-28) (EGF-SCI) was constructed. This gene was expressed using Bacillus brevis. EGF-SCI was isolated from the supernatant of the culture broth. Treatment of EGF-SCI with lysyl endopeptidase resulted in the formation of des-B30 human insulin. The identification of the formed des-B30 human insulin was made by the measurement of molecular weight and amino acid analysis. The binding coefficient to anti-human insulin antibody was comparable to that of human insulin.

Amino Acid Sequence↗

Distribution of sarcophytol A in soft coral of the Sarcophyton genus.

The distribution of sarcophytol-A in the Sarcophyton genus was investigated in seven samples belonging to S. glaucum (3 samples), S. infundibulifurme (2 samples), S. crassocaule (1 sample) and S. trocheliophorum (1 sample) that were collected on Ishigaki Island in Okinawa Prefecture. Sarcophytol-A was present in one sample each of S. glaucum and S. infundibulifurme. This study indicates that the composition of cembranoids in the Sarcophyton genus is not related with the respective species, but with the individual samples collected.

Animals↗

Constitutively active mitogen-activated protein kinase kinase increases GLUT1 expression and recruits both GLUT1 and GLUT4 at the cell surface in 3T3-L1 adipocytes.

To address a role of mitogen-activated protein kinase (MAPK) in the regulation of glucose transport, we made a constitutively active mutant of MAPK kinase (MAPKK) and introduced it into 3T3-L1 preadipocytes by using a retrovirus-mediated transfection procedure. The deletion of 20 amino acids (those between and including 32 and 51) in the amino terminal region of Xenopus MAPKK and the replacement of serine residues on the 218 and 222 positions by glutamic acid (dSESE-MAPKK) let Xenopus MAPKK constitutively active. The isolated cell clones differently expressing dSESE-MAPKK (clone 219 higher expression, clone 233 lower expression) efficiently differentiated to adipocytes by a standard differentiation cocktail. Accordingly, the increased expression of dSESE-MAPKK protein during differentiation resulted in the increased basal MAPK activity in clone 219 adipocytes and, to a lesser extent, in clone 233 adipocytes. In contrast to clone 233 and parental adipocytes, basal 2-deoxyglucose uptake was enhanced fourfold in clone 219 adipocytes, in accordance with increased expression of GLUT1 mRNA and protein. Whereas GLUT4 mRNA was similarly expressed in all of the adipocytes, GLUT4 protein appeared to decrease in clone 219 adipocytes. More importantly, subcellular fractionation studies showed that the localization of both GLUT1 and GLUT4 in the plasma membranes (PMs) was markedly increased in the basal state in clone 219 adipocytes compared with that in clone 233 and parental adipocytes, in which both glucose transporters were preferentially located in intracellular compartments. Consequently, insulin-induced translocation of GLUT1 was abolished in clone 219 adipocytes, although the remaining intracellular GLUT4 was still responsive to insulin stimulation, which led to the movement to the PM. As combined effects on the situation of GLUT1 and GLUT4, the foldness of insulin stimulation of glucose transport based on the basal activity was reduced in cells expressing constitutively active MAPKK. These results imply that chronic activation of MAPK could be one of the mechanisms for insulin resistance.

3T3 Cells↗

Idiopathic benign biliary stricture.

A rare case of idiopathic benign biliary stricture is reported. A 50-year-old man with liver dysfunction underwent ultrasonography, which revealed dilation of the intrahepatic bile ducts, and endoscopic retrograde cholangiopancreatography, which revealed a short, ring-like stenosis at the junction of the left and right hepatic ducts. Although a benign stricture was suspected, radiologic tests alone were insufficient to make a firm diagnosis. Therefore, a cholecystectomy and resection of the extrahepatic biliary tract were performed. Microscopic examination of the resected specimen demonstrated no evidence of malignancy. The final diagnosis was mild, localized, chronic cholangitis. The patient had not had previous biliary tract surgery, choledocholithiasis, nor did he have a congenital abnormality of the biliary tract, bile duct carcinoma, or pancreatic disease. Since there was no evidence of primary sclerosing cholangitis, the stricture was considered to be idiopathic.

Anastomosis, Surgical↗

Off-pump coronary bypass using interposed radial artery graft.

We describe a patient with severely diseased ascending aorta and small internal mammary arteries, who underwent off-pump coronary artery bypass to the left anterior descending coronary artery and right coronary artery using composite arterial grafts consisting of the pedicled proximal internal mammary artery and interposed radial artery graft. The interposed radial artery graft provides advantages, such as making coronary anastomosis on the beating heart easier and to increasing the flow potentiality of the internal mammary artery.

Aged↗

Annular pancreas diagnosed by single-shot MR cholangiopancreatography.

Magnetic resonance cholangiopancreatography (MRCP) has become widely used due to the rapid advances made as a non-invasive diagnostic method for the pancreatobiliary ducts. We report a case with annular pancreas in an adult in whom the pancreatic duct in the annular portion could be clearly visualized by magnetic resonance cholangiopancreatography, which was very useful for the definite diagnosis as annular pancreas.

Aged↗

The effect of T cell depletion with Campath-1M on immune reconstitution after chemotherapy and allogeneic bone marrow transplant as treatment for leukaemia.

The prophylactic use of T cell depletion (TCD) strategies for the prevention of graft-versus-host disease (GVHD) following allogeneic stem cell transplantation remains widespread. Initial reports of high incidence of graft rejection after TCD BMT led to a move away from this approach but improved conditioning regimens have reduced this risk substantially. The use of TCD has also been associated with higher relapse risk post-BMT although the success of donor leukocyte infusion (DLI) as treatment for relapse has reduced this problem, especially in chronic myeloid leukaemia (CML). Currently the use of TCD BMT is increasing particularly due to the relative increase in BMT from non-related donors for whom TCD is the optimal GVHD prophylaxis. However, doubts remain over the long-term effect on the reconstituted immune system of recipients of TCD BMT, particularly in adult recipients. In this study we have undertaken a detailed sequential analysis in 23 patients who received allo-grafts from HLA-identical sibling donors after high-dose chemo/radiotherapy for acute or chronic leukaemia. Of these patients, 11 received non-manipulated grafts, five received 'partially TCD' (PTCD) and a further seven received 'fully TCD' (FTCD) bone marrow. T cell depletion was performed ex vivo by Campath-1M plus autologous serum as a source of complement. Partial TCD describes grafts with a T cell reduction of 1-2 log. Full TCD refers to grafts with a reduction of >2.5 log. The decision regarding the optimal degree of TCD was clinical and was based upon the perceived relative risk of relapse based upon the disease and remission status. All patients were monitored for up to 12 months post-BMT with regard to reconstitution of T and NK cell subsets. T cell depletion at either level was associated with a slower recovery of CD4 cells. This was most marked in the FTCD recipients and lasted throughout the period of study. CD8 cell recovery was also slower in the TCD recipients but this normalised throughout the 12 months post-BMT. The ratio of CD45RA+:CD45RO+ increased in all recipients after month 3. This suggests that a degree of extra-thymic T cell maturation can occur in recipients of allogeneic BMT. NK cell recovery was more rapid in the TCD recipients and these differences were maintained throughout the first year.

Adult↗

FLAG-idarubicin and allogeneic stem cell transplantation for Ph-positive ALL beyond first remission.

We describe a single centre experience of eight consecutive patients with relapsed or refractory Ph+ ALL treated with the FLAG/idarubicin regimen followed by BMT or PBSCT. Following FLAG/idarubicin, one achieved a partial response and seven CR. All patients subsequently received allogeneic transplants: one sibling BMT, three matched unrelated (MUD) BMT and four sibling PBSCT. Two patients received second transplants with PBSC from their original BM donors following FLA/Ida with no further conditioning. Three patients are alive in CR 9, 24 and 32 months after transplant. Seven of eight patients had a cytogenetic response following FLAG/Ida induction and one of seven became bcr-abl negative. All eight patients had a complete cytogenetic response following transplant. Four of five assessable patients became p190 bcr-abl negative after transplant; three of these subsequently relapsed. Both patients with the p210 bcr-abl transcript remained bcr-abl positive in CR after transplant. FLAG/Ida was well tolerated and appears to be effective in inducing remission in relapsed Ph+ ALL. The use of FDR-containing chemotherapy without further conditioning prior to PBSCT deserves further study in heavily pre-treated patients and, in patients with relapsed ALL following BMT, may be a safer option than DLI (donor lymphocyte infusion) by avoiding the associated risk of aplasia.

Adolescent↗

Temporal dynamics of CD69 expression on lymphoid cells.

Lymphocyte activation remains an area of intense interest to immunologists and cell biologists and the dynamics of expression of surface molecules during the process are widely studied. The CD69 C-type lectin is reportedly the earliest activation antigen on lymphocytes and can be detected within hours of mitogenic stimulation. Recently reports have described differential activation dynamics with respect to different antigenic or mitogenic stimuli. This study has investigated the dynamics of CD69 expression over time after mitogenic, allogeneic, cytokine and target cell mediated activation of T-cell and NK cell subsets. It is apparent that the dynamics of CD69 expression differ with respect to the cell type and the method of stimulation. Mitogenic stimulation resulted in the most rapid expression of CD69 on both T- and NK cells while alloantigen stimulation induced a far slower response. Target cell stimulation of NK cells gave paradoxical results in that the CD69 + ve subset increased as a proportion of the total NK cells but did not increase in number. This was due to the selective binding of CD69 - ve NK cells to the target cells and their subsequent loss from the lymphoid gate. We confirmed this by showing that CD69 + ve NK cells do not lyse K562 target cells. This observation demonstrates the caution needed in the analysis of flow cytometric data based solely upon relative proportions of cells within discrete subsets.

Antigens, CD↗

(Stearyl, Norleucine17)VIP hybrid antagonizes VIP receptors on non-small cell lung cancer cells.

The effects of VIP receptor antagonists were investigated using non-small cell lung cancer (NSCLC) cells. By Northern blot and RT-PCR, VIP1 receptors were detected on NSCLC cell line NCI-H1299. VIPhybrid,(N-Stearyl-Norleucine17) VIPhybrid ((SN) VIPhybrid) and PTC4495 inhibited 125I-VIP binding to NCI-H1299 cells with IC50 values of 500, 30 and 5000 nM respectively. (SN) VIPhybrid (1 microM) had no effect on basal cAMP but strongly inhibited the increase in cAMP caused by 10 nM VIP. The order of peptide potency to inhibit cAMP was (SN) VIPhybrid > VIPhybrid > PTC4495. (SN) VIPhybrid was more potent than VIPhybrid at inhibiting NCI-H1299 colony formation. Also, (SN) VIPhybrid was more potent than VIPhybrid at inhibiting NCI-H1299 xenograft formation in nude mice. These data suggest that (SN) VIPhybrid antagonizes VIP1 receptors on NSCLC cells.

Amino Acid Sequence↗

A candidate case for lymphocytic infundibulo-neurohypophysitis mimicking a neurohypophysial tumor.

A 56-year-old Japanese man presented with a 2-month duration of polyuria and polydipsia. The diagnosis of diabetes insipidus was confirmed by water deprivation and vasopressin injection. The secretory function of the adenohypophysis was estimated as normal by a variety of provocative tests. Magnetic resonance imaging (MRI) displayed the loss of the hyperintense signal of the neurohypophysis and a tumor-like lesion confined to the neurohypophysis. The tissue specimen resected at transsphenoidal surgery showed diffuse lymphocytic infiltration. These findings suggest that this is a candidate case for lymphocytic infundibuloneurohypophysitis (LIN) that is not identical to classical lymphocytic hypophysitis. This patient will be followed up to determine whether this case simply represents an early stage of classical hypophysitis or a different clinical entity.

Diabetes Insipidus↗

Sequence evidence for strong conservation of the photoactive yellow proteins from the halophilic phototrophic bacteria Chromatium salexigens and Rhodospirillum salexigens.

The photoactive yellow proteins (PYP) have been found to date only in three species of halophilic purple phototrophic bacteria. They have photochemical activity remarkably similar to that of the bacteria rhodopsins. In contrast to rhodopsins, however, the PYPs are small water-soluble proteins. We now report the complete amino acid sequences of Rhodospirillum salexigens and Chromatium salexigens PYP which allow comparison with the known sequence and three-dimensional structure of the prototypic protein from Ectothiorhodospira halophila. Although isolated from three different families of bacteria, the PYP sequences are 70-76% identical. All three contain 125 amino acid residues, and no insertions or deletions are necessary for alignment. This is a remarkable result when it is considered that electron transfer proteins from these purple bacterial species are only 25-40% identical and that insertions and deletions are needed for their proper alignment. It thus appears that PYP has the same important function in each of the purple bacteria and that most of the amino acid residues are necessary to maintain structure and function. By most standards, PYP would be called a "slowly evolving protein". R. salexigens PYP is uniquely degraded by proteolysis at low ionic strength, probably as a consequence of unfolding due to electrostatic repulsion of the excess negative charge. Therefore it may also be classified as a "halophilic protein".

Amino Acid Sequence↗