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Biomedical subjects

M Yoshida

Publications and source records attributed to M Yoshida.

At least 199 records · Page 11Linked to original sources

A repeated pancreatectomy in the remnant pancreas 22 months after pylorus-preserving pancreatoduodenectomy for pancreatic adenocarcinoma.

We report a case of a repeated curative pancreatic resection in the remnant distal pancreas 22 months after pylorus-preserving pancreatoduodenectomy (PpPD). The patient was a 52-year-old woman with a past history of PpPD for adenocarcinoma of the head of the pancreas 22 months prior to the present operation. The original tumor was histopathologically diagnosed as a papillary adenocarcinoma with clear surgical margin at the surgical cut end of the pancreas (R0, International Union Against Cancer [UICC] classification). Twenty months after the PpPD, a follow-up computed tomography (CT) scan showed multiple low-density lesions in the body and tail of the pancreas without any other distant metastasis. A second operation, curative resection of the remnant pancreas, with splenectomy and distal gastrectomy, was performed. The second tumor was a papillary adenocarcinoma, the same diagnosis as that of the first tumor, and it also showed similar histopathological findings, including immunohistochemical staining of Ki-67 and p53 protein, and the same pattern of K-ras point mutation. The patient is considered to have shown a rare, unique pancreatic cancer with metachronous carcinogenesis in the remnant pancreas.

Adenocarcinoma, Papillary↗

Carcinoma of the cystic duct associated with pancreaticobiliary maljunction.

We report a rare case of carcinoma of the cystic duct (CCD) associated with pancreaticobiliary maljunction (PBM). A 63-year-old man had presented with relapsing cholecystitis of 4 months, duration. Computed tomography showed a distended gallbladder: however, small mass in the cystic duct was overlooked. Endoscopic retrograde cholangiopancreatography demonstrated a long common channel (20-mm-long) and fusiform dilatation of the common bile duct, findings, which were consistent with PBM. At laparotomy, we found a papillary tumor, 20 mm in diameter, that obstructed the cystic duct. The patient underwent resection of the gallbladder and the common bile duct, lymph node dissection in the hepatoduodenal ligament, and hepaticojejunostomy. Histologic study revealed a papillary adenocarcinoma confined within the subserosal space. There was no lymphatic or perineural invasion of cancer cells. The surrounding cystic ductal mucosa showed dysplasia and hyperplasia, and the gallbladder and common bile duct showed severe inflammation. The patient has been doing well for 16 months after surgery, without tumor recurrence. This case suggests a relationship between CCD and chronic biliary inflammation caused by PBM, as in cases of gallbladder carcinoma.

Adenocarcinoma, Papillary↗

The use of sintered bone in spinal surgery.

The sintered bovine bone True Bone Ceramics (TBC) is one of the biomaterials based on calcium phosphate, an organized crystal of bone mineral and a biomaterial possessing a natural trabecular structure. We examined whether the sintered bovine bone can integrate with recipient bone and adjust to the strength of recipient bone for anterior spinal fusion in an animal model. Based on radiographic evaluation, manual palpation, biomechanical testing, and histological examination, spinal fusion with TBC resulted in a composition and structure similar to that of autograft (and to no implantation). TBC, with its moderate strength, tended to adjust to the bone stiffness of the host bone in the respective specimens as new bone growth developed. Our observations warrant further clinical investigation of the use of sintered bone as an effective spinal arthrodesis, especially in patients who have fragile vertebrae, as in osteoporosis.

Animals↗

Sequential methotrexate and 5-fluorouracil therapy for gastric cancer patients with peritoneal dissemination: a retrospective study.

BACKGROUND: Most gastric cancer patients with peritoneal dissemination have been excluded from clinical studies because they usually have no measurable lesions. They also have a high risk of toxicity because of complications such as intestinal obstruction and ascites. We conducted a retrospective analysis to evaluate the efficacy and feasibility of sequential methotrexate (MTX) and 5-flurorouracil (5FU) therapy for this population. METHODS: This analysis was based on 56 consecutive chemotherapy-naive patients with confirmed peritoneal dissemination of gastric cancer who were being treated with sequential MTX/5FU. The therapy comprised a weekly schedule of MTX 100 mg/m2, given as a bolus infusion 3 h prior to a bolus infusion of 5FU 600 mg/m2. Leucovorin 10mg/m2 was administered six times, every 6h, starting 24h after MTX administration. RESULTS: Evidence of peritoneal dissemination was confirmed by laparotomy in 16 patients, by cytologic examination of ascites in 11 patients, and by clinical imaging in 29 patients (15 with ascites, 13 with intestinal obstruction; in 10 of the 29 patients, detection was by barium enema or computed tomography [CT] scan). Neutropenia of grade 3 or worse and anemia were observed in 8 (14%) and 10 (18%) of the 56 patients, respectively. There was one treatment-related death due to neutropenic sepsis. Of the 26 patients with measurable lesions, 9 showed a response (36%). The median survival time and median time to treatment failure were 259 days and 167 days, respectively. Objective improvement of ascites was seen in 13 of 26 patients (50%), including 5 with showed complete disappearance of ascites. Seven of the 15 patients (47%) with intestinal obstruction showed resolution, and 8 of the 21 patients (38%) who needed nutritional support before the treatment were free of that support for a median duration of 220 days after the completion of the treatment. Forty-seven of the 56 patients (84%) could be treated at outpatient clinics. CONCLUSIONS: This regimen may be of clinical benefit for patients with peritoneal dissemination of gastric cancer.

Adult↗

Repair of atrial septal defect through a right posterolateral thoracotomy: a cosmetic approach for female patients.

BACKGROUND: Because the operation for atrial septal defect is considered a low-risk procedure, the cosmetic result has become an important issue. Principally for cosmetic reasons, anterolateral thoracotomy is frequently used for closure of atrial septal defect in young female patients. However, in anterolateral thoracotomy, the skin incision frequently crosses the future breast line, which may cause breast and pectoral muscle maldevelopment. METHODS: We review the long-term results of a consecutive series of 126 patients in whom the atrial septal defect was closed through a right posterolateral thoracotomy. The mean age at operation was 7.1 years (range, 1 to 15 years), and the mean body weight was 23.9 kg (range, 6.9 to 56 kg). Defects repaired included 121 ostium secundum (central type), 3 sinus venosus, and 2 ostium secundum without inferior margin. RESULTS: The average cardiopulmonary bypass time was 65 minutes (range, 37 to 130 minutes), with an average fibrillation time of 41 minutes (range, 23 to 70 minutes). There was no operative or late mortality. A majority of patients were pleased with their cosmetic results. There were no other late complications. CONCLUSIONS: Atrial septal defect can be safely repaired through a right posterolateral thoracotomy approach. This approach offers the benefit of a total absence of scarring and cosmetic disfigurement of the anterior chest wall.

Adolescent↗

Task-dependent strain difference of spatial learning in C57BL/6N and BALB/c mice.

In the present study, we used a dry maze task to assess the spatial learning ability of C57BL/6N and BALB/cA mice besides the water maze task. In Experiment 1, the performance of C57BL/6N and BALB/cA mice in the water maze task and dry maze task were investigated. In the former task, the mice had to learn the position of a hidden platform submerged below the water surface and they had to learn the position of a baited hole on the circular maze in the latter task. C57BL/6N mice showed significant learning in both maze tasks, whereas BALB/cA mice showed learning in a dry maze but not in water maze as reported before. In Experiment 2, a dry maze task was conducted on a circular open field which contained 16 holes arranged symmetrically and which was put on the same height as the surface of the water maze. In Experiment 2, BALB/cA mice showed significant improvement in latency and path length to reach the food hole. The poor performance of the BALB/cA in the water maze task may reflect a weak motivation, escaping from water, rather than the poor spatial memory in this strain.

Animals↗

Lipophyllic antioxidants from Iryanthera juruensis fruits.

The phytochemical investigation of the hexane extract of Iryanthera juruensis (Myristicaceae) fruits led to the isolation of two tocotrienols and four lignans which exhibited antioxidant activity towards beta-carotene on TLC autographic assay. Two inactive quinones and three omega-arylalkanoic acids were also isolated. The isolates were investigated for their redox properties using cyclic voltammetry. The structure elucidation of the new compounds (one tocotrienol. one quinone and three omega-arylalkanoic acids) was based on analysis of spectroscopic data.

Antioxidants↗

Age-related changes in cholinergic and purinergic neurotransmission in human isolated bladder smooth muscles.

We evaluated the correlation among age, cholinergic and purinergic neurotransmissions in the electrical field stimulation-induced contractions in human isolated urinary bladder smooth muscles, using the muscle bath technique. Human bladder specimens were divided into three groups (G1, under 50years; G2, 51-70years; G3, over 70years old), and each muscle strip was suspended in a thermostatically controlled organ bath filled with oxygenated Krebs-Henseleit solution, connected to an isometric force displacement transducer, and an isometric tension development was recorded. The contractile responses induced by KCl, carbachol, adenosine triphosphate (ATP) and electrical field stimulation, and the effects of atropine and alpha, beta methylene ATP on electrical field stimulation-induced contractions were observed. The contractile response to KCl and concentration-response curves for carbachol and ATP, and frequency-response curves for electrical field stimulation were not significantly different among the three groups. The atropine sensitive and resistant parts of contraction induced by electrical field stimulation were decreased and increased with age, respectively. There are significant positive and negative correlations between age and the purinergic, and age and the cholinergic neurotransmissions in human isolated bladder smooth muscles, respectively. The age-related changes in neurotransmissions may contribute to the changes in bladder function in the elderly.

Adenosine Triphosphate↗

Intraocular lens power calculation for lens exchange.

PURPOSE: To examine patients who had intraocular lens (IOL) exchange for large postoperative refractive errors and determine the factors that contributed to the error in IOL power calculation. SETTING: Thirteen affiliated hospitals in Japan. METHODS: This study comprised 34 cases that required IOL exchange because of large refractive errors after primary lens implantation. Patients with intraoperative complications were excluded from the study. The potential contribution of axial length, corneal refractive power, IOL manufacturer, and IOL fixation to errors in the predicted power was examined retrospectively. Axial length was calculated by the SRK/T and Holladay formulas using refraction after primary IOL implantation. RESULTS: There was no statistical difference between the corneal refractive power before and after cataract surgery. The axial lengths calculated using the SRK/T and Holladay formulas were longer than the ultrasonic axial lengths in 24 and 23 cases, respectively. Using IOLs from the same manufacturer for both primary implantation and exchange reduced the error in predicted refraction. CONCLUSION: Axial length and IOL manufacturer were important factors in predicting refraction power in eyes requiring IOL exchange.

Aged↗

Age-specific prevalence of open-angle glaucoma and its relationship to refraction among more than 60,000 asymptomatic Japanese subjects.

To clarify the prevalence of open-angle glaucoma (OAG) and its relationship to refraction among a Japanese population with a broad range of ages including children and adolescents, an 1-year epidemiological survey was conducted. The subjects of this study were 64,394 asymptomatic individuals who had attended the glasses and contact lens center in Yokohama, Japan from February 15, 1999 to February 14, 2000 and had been subjected to several optical examinations. The results of this study showed that the overall prevalence of OAG was 1.19% (1.14% for men, and 0.98% for women). Prevalence for children aged 6 to 14 of both sexes was approximately 0.5%. There were significant positive associations between the strength (diopter) of myopic refraction and OAG prevalence among all the examined subjects.

Adolescent↗

Effect of riluzole on the acquisition and expression of amygdala kindling.

PURPOSE: Riluzole possesses various synaptic effects including an inhibitory action on glutamate release. The drug has been shown to inhibit kindled seizures, while its effect on the acquisition of kindling has not been reported. We investigated effects of riluzole on the kindling development in addition to effects on kindled seizures. METHODS: A bipolar electrode was implanted in the right amygdala of rats. Riluzole was injected intraperitoneally 30 min before kindling stimulation. To investigate effects of riluzole on the kindling development, rats were stimulated once daily for the drug session of 14 days at a current of 200 microA, 60 Hz, 1 ms for 2 s and thereafter stimulated without drugs (drug-free session) until completion of kindling. Seizure ranks and after discharge duration were observed every day. To investigate effects of riluzole on kindled seizures, fully-kindled rats were stimulated at the current of generalized seizure threshold (GST) before and after the administration of riluzole. Seizure ranks and after discharge duration were measured. GST after the treatment was also determined. RESULTS: The number of stimuli required for the first appearance of stage five seizure was significantly larger in rats treated with 8 mg/kg of riluzole than in vehicle controls. Riluzole at a dose of 8 mg/kg significantly retarded the development of seizure stages in the drug session. By comparison, effects on the duration of after discharge was relatively mild, though significantly different from the vehicle control. Riluzole at a dose of either 4 or 8 mg/kg markedly inhibited behavioral seizures and reduced the duration of after discharge in kindled seizures provoked by GST. The drug also significantly increased GST at both doses, suggesting that the anticonvulsant effects were attributed to the increase in GST. CONCLUSION: It was demonstrated that inhibitory effects of riluzole on both kindled seizures and the development of behavioral seizures in kindling acquisition with relatively mild correlation to afterdischarge duration. These effects might be attributed to inhibitory actions of riluzole on glutamate release and NMDA-receptor mediated events.

Amygdala↗

GM-CSF regulates alveolar macrophage differentiation and innate immunity in the lung through PU.1.

GM-CSF gene targeted (GM(-/-)) mice are susceptible to respiratory infections and develop alveolar proteinosis due to defects in innate immune function and surfactant catabolism in alveolar macrophages (AMs), respectively. Reduced cell adhesion, phagocytosis, pathogen killing, mannose- and Toll-like receptor expression, and LPS- or peptidoglycan-stimulated TNFalpha release were observed in AMs from GM(-/-) mice. The transcription factor PU.1 was markedly reduced in AMs of GM(-/-) mice in vivo and was restored by selective expression of GM-CSF in the lungs of SPC-GM/GM(-/-) transgenic mice. Retrovirus-mediated expression of PU.1 in AMs from GM(-/-) mice rescued host defense functions and surfactant catabolism by AMs. We conclude that PU.1 mediates GM-CSF-dependent effects on terminal differentiation of AMs regulating innate immune functions and surfactant catabolism by AMs.

Animals↗

Weighted HOMO-LUMO energy separations of properly closed-shell fullerene isomers.

The HOMO-LUMO energy separation has been used as an index of kinetic stability for fullerenes. However, its utility is rather limited, in that a larger fullerene molecule in general has a smaller HOMO-LUMO energy separation even if it is kinetically stable. The T value, i.e., the HOMO-LUMO energy separation weighted with the number of carbon atoms, is free from this kind of difficulty. Properly closed-shell isomers of fullerenes with antibonding LUMOs were found to have an exceptionally large T value irrespective of the number of constituent carbon atoms and are hence predicted to be kinetically very stable. Thus, the antibonding character of the LUMOs is one of the determinants for kinetically stabilizing fullerene molecules.

Carbon↗

Chemical characterisation of the oligosaccharides in hooded seal (Cystophora cristata) and Australian fur seal (Arctocephalus pusillus doriferus) milk.

Carbohydrates were extracted from hooded seal milk, Crystophora cristata (family Phocidae). Free oligosaccharides were separated by gel filtration and then purified by ion exchange chromatography, gel filtration and preparative thin layer or paper chromatography and their structures determined by 1H-NMR. The hooded seal milk was found to contain inositol and at least nine oligosaccharides, most of which had lacto-N-neotetraose or lacto-N-neohexaose as core units, similar to those in milk of other species of Carnivora such as bears (Ursidae). Their structures were as follows: Gal(beta1-4)Glc (lactose); Fuc(alpha1-2)Gal(beta1-4)Glc (2'-fucosyllactose); Gal(beta1-4)GlcNAc(beta1-3)Gal(beta1-4)Glc (lacto-N-neotetraose); Fuc(alpha1-2)Gal(beta1-4)GlcNAc(beta1-3)Gal(beta1-4)Glc (lacto-N-fucopentaose IV); Gal(beta1-4)GlcNAc(beta1-3)[Gal(beta1-4)GlcNAc(beta1-6)]Gal(1-4)Glc (lacto-N-neohexaose); Fuc(alpha1-2)Gal(beta1-4)GlcNAc(beta1-3)[Gal(beta1-4)GlcNAc(beta1-6)]Gal(beta1-4)Glc (monofucosyl lacto-N-neohexaose a); Gal(beta1-4)GlcNAc(beta1-3)[Fuc(alpha1-2)Gal(beta1-4)GlcNAc(beta1-6)]Gal(beta1-4)Glc (monofucosyl lacto-N-neohexaose b); Fuc(alpha1-2)Gal(beta1-4)GlcNAc(beta1-3)[Fuc(alpha1-2)Gal(beta1-4)GlcNAc(beta1-6)]Gal(beta1-4)Glc (difucosyl lacto-N-neohexaose); Gal(beta1-4)GlcNAc(beta1-3)Gal(beta1-4)GlcNAc(beta1-3)Gal(beta1-4)Glc (para lacto-N-neohexaose); Fuc(alpha1-2)Gal(beta1-4)GlcNAc(beta1-3)Gal(beta1-4)GlcNAc(beta1-3)Gal(beta1-4)Glc (monofucosyl para lacto-N-neohexaose). Milk of the Australian fur seal, Arctophalus pusillus doriferus (family Otariidae) contained inositol but no lactose or free oligosaccharides. These results, therefore, support the hypothesis that the milk of otariids, unlike that of phocids, contains no free reducing saccharides.

Animals↗

The magnitude of variation in temperature within a year has an effect on the seasonal variations of chickenpox incidence in Japan.

We investigated the epidemic pattern of chickenpox incidence among 47 prefectures in Japan. There were two peaks in chickenpox incidence in all prefectures. The first peaks appear at almost the same time in a year, while the second peaks occur at different times with relatively different types of size and shape. The feature of the second peak might characterize the epidemic pattern of chickenpox. We first introduced the second peak index, that is, the ratio of the difference between the incidence at the point of the second peak and the minimum incidence between the first and second peaks to the difference between the incidence at the point of the second peak and the minimum incidence in the year. There was a close correlation between the second peak index and the magnitude of variation in temperature within a year corresponding to the difference between the maximum and the minimum of the monthly mean of the highest daily temperature. This is the first article focusing on the close relationship between the second peak of epidemic pattern of chickenpox incidence and the variation of temperature within a year.

Chickenpox↗

Structural analysis of a novel antimutagenic compound, 4-Hydroxypanduratin A, and the antimutagenic activity of flavonoids in a Thai spice, fingerroot (Boesenbergia pandurata Schult.) against mutagenic heterocyclic amines.

Six compounds were isolated from fresh rhizomes of fingerroot (Boesenbergia pandurata Schult.) as strong antimutagens toward 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) in Salmonella typhimurium TA98. These compounds were 2',4',6'-trihydroxychalcone (pinocembrin chalcone; 1), 2',4'-dihydroxy-6'-methoxychalcone (cardamonin; 2), 5,7-dihydroxyflavanone (pinocembrin; 3), 5-hydroxy-7-methoxyflavanone (pinostrobin; 4), (2,4,6-trihydroxyphenyl)-[3'-methyl-2'-(3' '-methylbut-2' '-enyl)-6'-phenylcyclohex-3'-enyl]methanone (5), and (2,6-dihydroxy-4-methoxyphenyl)-[3'-methyl-2'-(3' '-methylbut-2' '-enyl)-6'-phenylcyclohex-3'-enyl]methanone (panduratin A; 6). Compound 5 was a novel compound (tentatively termed 4-hydroxypanduratin A), and 1 was not previously reported in this plant, whereas 2-4 and 6 were known compounds. The antimutagenic IC(50) values of compounds 1-6 were 5.2 +/- 0.4, 5.9 +/- 0.7, 6.9 +/- 0.8, 5.3 +/- 1.0, 12.7 +/- 0.7, and 12.1 +/- 0.8 microM in the preincubation mixture, respectively. They also similarly inhibited the mutagenicity of 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2) and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP). All of them strongly inhibited the N-hydroxylation of Trp-P-2. Thus, the antimutagenic effect of compounds 1-6 was mainly due to the inhibition of the first step of enzymatic activation of heterocyclic amines.

Amines↗

Lysophosphatidylcholine activates transcription factor NF-kappaB and AP-1 in AR42J cells.

Phospholipase A2 (PLA2) has been suggested in the pathogenesis of acute pancreatitis, in part through the PLA2-generated phospholipid by-products, most notably lysophosphatidylcholine (lyso-PC). The effects of lyso-PC on pancreatic acinar cells other than necrosis are poorly characterized. Recent studies have suggested a role of the activation of transcription factors such as nuclear factor kappa B (NF-kappaB) for the pathogenesis of acute pancreatitis. Here we examined the effects of lyso-PC on the activation of transcriptional factors in rat pancreatic AR42J cells. Lyso-PC induced apoptosis at concentrations > or = 10 microM. At 10 and 25 microM, lyso-PC increased the NF-kappaB- and activator protein-1 (AP-1)-specific DNA binding activity as determined by electrophoretic mobility shift assay. Lyso-PC also increased the transcriptional activity of NF-kappaB and AP-1 as assessed by luciferase assay. Lyso-PC increased the mRNA level of pancreatitis-associated protein-I and c-jun. Lyso-PC activated three classes of mitogen activated protein kinases: extracellular signal-regulated kinase 1/2, c-Jun NH2-terminal kinase/stress-activated protein kinase and p38 kinases. Activation of transcription factors by lyso-PC was not altered by a specific platelet activating factor receptor antagonist, TCV-309, suggesting that the activation was independent of the platelet activating factor receptor. These molecular events may suggest a novel role of lyso-PC for the modulation of acinar cell function.

Acute Disease↗