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Biomedical subjects

K Imamura

Publications and source records attributed to K Imamura.

466 records · Page 26Linked to original sources
PubMedDate not supplied

Efficiency and biocompatibility of a polyethylene glycol grafted cellulosic membrane during hemodialysis.

Dialytic efficiency and biocompatibility of a new modified cellulose membrane (NMC) were examined in vitro and clinically. NMC was obtained by grafting polyethylene-glycol (PEG) chains to the membrane surface of ordinary cellulose (OC), and it was expected that the random movement of PEG chains would prevent blood cells and large plasma proteins from coming into contact with the membrane surface, resulting in improving the biocompatibility and thrombogenicity of the membrane. Surface characteristics of NMC were rendered anionic and hydrophilic, however, the activations of complement and platelet systems were clearly suppressed in NMC. Minimum heparin requirement for hemodialysis was significantly lower with NMC than with OC dialyzer. No significant difference in solute and water removal was observed between the two dialyzers. These results indicate that NMC can provide increased biocompatibility and antithrombogenic effect while retaining the essential dialysis efficiency of OC.

Biocompatible Materials↗
PubMedDate not supplied

Quantitative in vivo measurement of thyroidal iodine content by static x-ray fluorescent technique: some preliminary clinical observations.

A static x-ray fluorescent technique utilizing an 241Am source of low activity and a wide view diverging collimator which allows in vivo determination of the concentration and total content of iodine in the thyroid is described. Determinations of normal thyroidal iodine concentration and total iodine content were as follows: 0.40 mg/g and 10.6 mg for 16 men, and 0.67 mg/g and 17.6 mg for 14 women. This fluorescent system has been applied to 70 patients to date. Thyroidal iodine concentrations in patients with Graves' disease were approximately equal to those in healthy suspects, and little change was observed among the concentrations in patients before, during, or after treatment. In most of the patients with chronic or subacute thyroiditis, concentrations levels were lower.

Adult↗
PubMedDate not supplied

Peripheral nerve intraneural ganglion cyst: MR findings in three cases.

We present MR findings of three cases of surgically proved intraneural ganglion cysts involving the common peroneal nerve (two patients) and ulnar nerve (one patient). The lesions were located along the course of the involved nerve and situated close to a joint. MRI demonstrated the cystic nature and extent of the lesions with clear definition of the anatomic relationship of the lesions to the surrounding structures.

Adult↗
PubMedDate not supplied

Changes in plasma fatty acid profile in Japanese patients with chronic pancreatitis.

The serum zinc, prealbumin, retinol-binding protein and carotene concentrations and the plasma fatty acid composition were determined to assess the nutritional condition of 24 patients with chronic pancreatitis compared with that of 20 healthy controls. The daily food intake and faecal fat excretion of the two groups were also measured. In the chronic pancreatitis group, the calorie and fat intakes were significantly lower than those of the controls. Serum levels of zinc, prealbumin and carotene were also significantly lower than those of the controls. Percentages of plasma linoleic and arachidonic acids were low, while percentages of palmitoleic acid, eicosapentaenoic acid and docosahexaenoic acid were high. Fish oil intake correlated negatively with plasma linoleic acid concentration (P < 0.05). The above results indicate that the relatively high intake of fish oil and the relatively low intake of dietary fat in Japanese patients with chronic pancreatitis with a mild degree of steatorrhoea results in an abnormally low plasma level of linoleic acid.

Adult↗
PubMedDate not supplied

Effects of pancreatic digestive enzymes, sodium bicarbonate, and a proton pump inhibitor on steatorrhoea caused by pancreatic diseases.

Forty-five patients with pancreatic steatorrhoea (27 with calcified pancreatitis, 13 with non-calcified pancreatitis, two with pancreaticoduodenectomy, one with total pancreatectomy, and two with pancreatic cancer) were divided into four groups and given the following medication for 2 to 4 weeks: 4 to 6 g/day of sodium bicarbonate (group I); 9 g/day of high-lipase pancreatin (lipase, 56,600 U/g, Fédération Internationale Pharmaceutique (FIP); group II); 12 to 24 tablets or 9.0 g of commercial pancreatic enzyme preparations (group III); or 50 mg of omeprazole (group IV). Faecal fat excretion was evaluated before and after drug administration. Faecal fat excretion was reduced by 2.9 g (range, 1.7 to 5.0 g) in group I; 8.8 g (range, 2.9 to 39.9 g) in group II; 10.8 g (range, 2.3 to 21.8 g) in group III; and 4.3 g (range, 3.6 to 5.6 g) in group IV. The pancreatic digestive enzyme preparation was more effective than sodium bicarbonate and agents that raise the pH of the upper small intestine (such as proton-pump inhibitors) in reducing faecal fat excretion. The results indicate that all of the preparations used are effective against mild pancreatic steatorrhoea. If the condition is more advanced, however, a massive dosage of pancreatic digestive enzyme and possibly the combined use of an agent to raise the pH of the upper small intestine are likely to be effective.

Adult↗
PubMedDate not supplied

Faecal triglycerides and fatty acids in the differential diagnosis of pancreatic insufficiency and intestinal malabsorption in patients with low fat intakes.

To investigate possible parameters for the differential diagnosis of steatorrhoea in patients with low fat intakes, faecal specimens were analysed from 15 patients with steatorrhoea due to chronic pancreatitis and seven patients with steatorrhoea due to intestinal malabsorption. The fat intakes of the patients ranged from 30.1 to 60 g, less than the average in American and European patients. The group with pancreatic steatorrhoea showed a significantly lower faecal output than the group with intestinal steatorrhoea but the two groups did not differ significantly in their total faecal fat excretion or concentration. The percentage triglycerides and the molecular ratio of triglycerides to fatty acids in the faeces were significantly higher (P < 0.01) in the group with pancreatic steatorrhoea than in those with intestinal steatorrhoea. The molecular percentage ratio of triglycerides to fatty acids was 6.8 +/- 2.2 for the chronic pancreatitis group and 2.4 +/- 1.0 for the intestinal malabsorption group; while the respective faecal hydroxy fatty acid contents were 3.1 +/- 3.6% and 10.1 +/- 3.3% (means +/- SDs). These latter two parameters appeared to be the most valuable for distinguishing the two forms of steatorrhoea.

Adult↗
PubMedDate not supplied

Corticobasal degeneration: an autopsy case clinically diagnosed as progressive supranuclear palsy.

We report an autopsy case diagnosed clinically as progressive supranuclear palsy (PSP), but neuropathologically confirmed as corticobasal degeneration (CBD). A 56-year-old Japanese woman slowly developed parkinsonism, dementia, character change, followed by vertical gaze palsy and dystonia. Brain MRI demonstrated diffuse cerebral atrophy with severe shrinkage of the brain stem tegmentum. The SPECT images using 123I-IMP disclosed symmetrical hypoperfusion in the frontal lobes. She died of respiratory failure at the age of 71. Gross inspection of the brain showed diffuse, symmetrical atrophy of the cerebrum and marked atrophy of the Luysian body, globus pallidus, substantia nigra and nuclei of the brain stem tegmentum. Microscopically, neuronal loss and fibrillary gliosis were observed in the Luysian body, globus pallidus, substantia nigra and nuclei of the brain stem tegmentum. The cerebellar dentate nucleus showed mild neuronal loss with some grumose degeneration. Neurofibrillary tangles were found only in the Luysian body, substantia nigra and raphe nuclei, whilst tau-positive inclusions were observed more extensively. Astrocytic plaques and swollen achromatic neurones were found in the postcentral gyrus. There were no tuft-shaped astrocytes in the brain. The clinicopathological similarities and differences between PSP and CBD are discussed.

Aged↗
PubMedDate not supplied

Ionic strength affects diffusive permeability to an inorganic phosphate ion of negatively charged dialysis membranes.

Electrolytes undergo electrostatic resistances in reaching membrane surfaces and passing through membrane pores when weakly charged dialysis membranes are used in hemodialysis treatments. Diffusive permeability to an electrolyte of weakly charged dialysis membranes depends upon the effective charge density of the membranes, which varies with ionic strength. The authors carried out dialysis experiments at a temperature of 310 K, with 32P-Na2HPO4 in aqueous NaCl and bovine serum, to obtain diffusive permeability to an inorganic phosphate ion of regenerated cellulose, and polymethylmethacrylate membranes of various fixed charge densities at varying ionic strengths ranging from 1.66 to 100 mol/m3. Diffusive permeability to an inorganic phosphate ion increased with ionic strength. Bovine serum, having an ionic strength of approximately 150 mol/m3, gave higher diffusive permeability to an inorganic phosphate ion. The internal structure of dialysis membranes, such as pore size, surface porosity, and tortuosity, also affects diffusive permeability. The electrolyte diffusion theory gives an effective charge density of -5.3 mol/m3 for the cellulosic membrane. In conclusion, ionic strength enhances diffusive permeability to an inorganic phosphate ion in both aqueous NaCl and bovine serum. Inorganic phosphate ion transport through negatively charged dialysis membranes depends upon the degree of dissociation of inorganic phosphate, the molecular size and valence of hydrated inorganic phosphate ion, the effective charge density and internal structure of the membrane, and ionic strength.

Animals↗
PubMedDate not supplied

Clinical effects of a polyethylene glycol grafted cellulose membrane on thrombogenicity and biocompatibility during hemodialysis.

The biocompatibility and thrombogenicity of polyethylene-glycol (PEG)-grafted cellulose hemodialysis (HD) membranes (PEGC) were investigated in cross-over HD of five HD patients with ordinary cellulose (OC). The PEGC significantly suppressed transient leukocyte and thrombocytopenia, and release of C3a, beta-thromboglobulin and platelet factor 4, in corresponding with the quantity of grafted PEG. HD with PEGC resulted in lower granulocyte elastase production, protein and blood cells adsorption on the membrane surface than those with OC. Minimum heparin in HD with PEGC was three times lower than that with OC, with the thrombin-antithrombin III complex elevation lower than that in HD with OC. The results indicate that the grafted PEG effectively suppresses blood and membrane interaction, thus improving biocompatibility and reducing thrombogenicity in clinical HD.

Biocompatible Materials↗
PubMedDate not supplied

Development of a regenerated cellulose non-complement activating membrane for hemodialysis.

We have developed a new cellulose membrane in which the active hydroxyl and carboxyl groups of the original cellulose fibers are masked with cationic synthetic polymers. The membrane was shown by in vitro and clinical tests to affect the activation of the complement system very little, and it retains the high dialysis efficiency, good tolerance to steam autoclave sterilization, and economical production cost characteristics of the original cellulose membrane. It thus appears that the new cellulose provides the optimum combination of qualities needed in a hemodialysis membrane.

Cellulose↗
PubMedDate not supplied

Pheochromocytoma with multiple islet cell carcinoma.

We reported a rare case of a 17-year-old female with pheochromocytoma associated with multiple islet cell carcinoma. Pheochromocytoma was identified in the right adrenal gland. Multiple pancreas tumours were demonstrated unpredictably in the diagnostic imaging of the pheochromocytoma. No other endocrinological neoplasm was observed in the pituitary, thyroid and parathyroid gland. The patient underwent right adrenalectomy and total pancreatectomy. Pheochromocytoma was benign, however, pancreas tumours were non-functioning islet cell tumours and histologically malignant. This combination is assumed to represent a mixed form of multiple endocrine neoplasia (MEN) 1 and MEN 2.

Adolescent↗
PubMedDate not supplied

Fat-soluble vitamins in patients with chronic pancreatitis (pancreatic insufficiency).

The fat-soluble vitamin contents in the blood (vitamins A, D, E, and K) were determined in 12 patients with chronic pancreatitis (exocrine pancreatic insufficiency) and in 20 healthy adults by the HPLC and CPBA methods. In addition, 9 g (3 g x 3 times) of high potency pancreatin was given to 11 patients with chronic pancreatitis (CP) for approximately 1 month and changes in the blood fat-soluble vitamin levels were evaluated before and after the treatment. The major component of vitamin E was alpha-tocopherol. The mean alpha-tocopherol level in normal individuals was 0.97 mg/dl, while it was significantly reduced in CP patients (p < 0.01). The vitamin A, D, and K levels had also been reduced in patients with CP, but the differences were not significant (although some patients in this group exhibited significant reductions from the levels of normal individuals). Only the blood vitamin E level showed a significant correlation with the fecal fat excretion or the fat absorption rate. None of the patients with CP exhibited an overt fat-soluble vitamin deficiency (i.e., the deficiency of fat-soluble vitamins was at a subclinical level). These results indicated that CP patients suffer from a latent fat-soluble vitamin deficiency and that the vitamin E level is closely related to a dysfunction of fat digestion. It was suggested that the dietary intake of each fat-soluble vitamin should be evaluated further.

Adult↗
PubMedDate not supplied

The role of stress-related physical confinement in the pathogenesis of acute gastric hemorrhage after alcohol instillation in rats.

The combination of alcohol and stress have been considered producers of gastric hemorrhage both experimentally and in clinical observations. Since excessive alcohol intake often occurs in situations of severe emotional conflict and stress, it was decided to study the possible role of the latter in the etiology of gastric hemorrhage, up to now thought to be dependent only on alcohol. The study consists of 75 male Wistar rats divided into eight groups with seven to 14 animals each. They were submitted to fasting only, or to additional prolonged fasting, restraint-stress (physical confinement) for 17 hours and the oral administration of a single dose of 40% alcohol (1 ml/150 g of body weight). The stomachs were analyzed macroscopically and microscopically for the presence of gastric hemorrhage, and the following was observed; 1) only 10% of the rats submitted to a 25 hour fast either isolated or associated with 17 hours of physical confinement, demonstrated gastric hemorrhage; 2) after an eight hour fast, the administration of alcohol to the rats either sacrificed immediately or maintained for 17 hours, revealed gastric lesions in only 33.3% and 28.5% respectively, without significant statistical difference between the two groups (P > 0.05); 3) administration of alcohol prior to the 17 hour physical confinement revealed lesions in only 12.5% of the animals; 4) administration of alcohol to rats previously submitted to a 25 hour fast plus physical confinement for 17 hours, resulted in a significant number of hemorrhagic lesions (88.8%). This caused a statistical difference in the group compared to the others (P < 0.01). The results of this study led to the conclusion that stress (by prolonged physical confinement) was an important conditioning factor to the appearance of gastric hemorrhage when 40% alcohol was administered. It is possible that if the alcohol had been administered prior to the prolonged physical confinement its cytotoxic effect on the gastric mucosa might have been reduced.

Acute Disease↗
PubMedDate not supplied

Meal-related changes in plasma CCK bioactivity in patients with chronic pancreatitis.

In order to clarify whether there is a negative feedback mechanism for CCK secretion, we investigated plasma CCK bioactivity in patients suffering from chronic pancreatitis (CP) according to the characteristics of their pancreatic disease. Basal, meal-stimulated, and integrated release of plasma cholecystokinin (CCK) bioactivity was measured in 24 patients with CP and in 12 healthy controls. The values obtained were compared between the healthy control group and the CP group, and between subgroups of CP patients established on the basis of the presence/absence of several parameters: abnormal gastric emptying, abdominal pain, steatorrhea, pancreatic calcification, insulin-requiring diabetes mellitus, and impairment of pancreatic exocrine functions as indicated by secretin test. A bioassay method using pancreatic acini was used to measure plasma CCK bioactivity. In the control group, plasma CCK bioactivity increased from a basal value of 1.6 +/- 0.7 pmol/L to a maximal increase of 6.6 +/- 4.1 pmol/L, and the integrated CCK release following a test meal was 37.7 +/- 19.3 pmol/L.150 min. In the CP group, plasma CCK bioactivity increased from 1.6 +/- 0.9 pmol/L to a maximal increase of 8.2 +/- 8.7 pmol/L, and the integrated release of CCK was 43.0 +/- 37.7 pmol/L.150 min. None of the differences between them were significant. No significant differences in basal value, maximal increase, or integrated plasma CCK release were noted according to any of the parameters of the CP patients and the control group. Nor was there any correlation between impairment of pancreatic exocrine function and plasma CCK bioactivity. These results provide no evidence of a negative feedback mechanism between pancreatic exocrine dysfunction and CCK secretion.

Adult↗