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Biomedical subjects

K Machida

Publications and source records attributed to K Machida.

At least 145 records · Page 8Linked to original sources
PubMed1994

[Measurement of cerebral blood flow in normal subjects by phase contrast MR imaging].

Global cerebral blood flow (CBF) was quantitatively measured with a two-dimensional phase contrast cine magnetic resonance (MR) imaging technique in 24 normal subjects (mean age, 38.6 years; range, 12-70 years). Cine transverse images of the upper cervical region (32 phases/cardiac cycle) were acquired with a 1.5 Tesla MR imaging unit. In five subjects, measurement of CBF was performed before and after intravenous administration of acetazolamide (DIAMOX, 15 mg/kg). Inter- and intraobserver variations in flow volume measurement were small (r = 0.970, standard error of the estimate (SEE) = 2.9 ml/min, n = 80; r = 0.963, SEE = 4.6 ml/min, n = 40, respectively). In measuring flow velocity, they were inferior to those of flow volume measurement. On a visually determined setting of region of interest (ROI), reproducibly of the measurement of flow velocity was not satisfactory in this study. Thus only the results of flow volume measurement are presented. Mean summed vertebral flow volume (171 ml/min, SD = 40.6) was significantly less than mean summed internal carotid flow volume (523 ml/min, SD = 111). Total blood flow volume showed a significant decline with age (r = 0.45, p < 0.05). The mean proportions of carotid and vertebral flow volume to total flow volume were 75.3% and 24.7%, respectively, and showed no significant change with age. The left-to-right ratio of vertebral flow volume (1.39) was significantly higher than that of internal carotid flow volume (0.99, r = 0.05). After DIAMOX i.v., the mean rate of increase in total flow volume was 157%. Mean rates of increase in carotid and vertebral flow volume were 154% and 166%, respectively, which were not significantly different. In conclusion, this method is useful for estimating carotid and vertebral flow volume.

Acetazolamide↗
PubMed1994

Dietary analysis of Japanese patients with chronic pancreatitis in stable conditions.

In order to examine the malnutritional condition of outpatients with pancreatitis, a dietary investigation was conducted in Japanese patients with chronic pancreatitis (n = 38) and healthy subjects (n = 35) of the same age for 3-7 consecutive days, and the characteristics of their food intake were examined. The patients with pancreatitis took in less calories, fat, carbohydrate, and protein than the healthy subjects, by 900 kcal, 20 g, 150 g, and 20 g, respectively. On the other hand, the fat energy ratio in the patients was 20%, similar to that in the healthy subjects. Also, when the fat intake was classified according to origin, i.e., animal, marine, or plant, the proportions for animal (g) and plant (g) were low, while marine fat accounted for a significantly higher percentage than in the healthy subjects. The intake of cholesterol and Ca in the patients was significantly smaller than that in the healthy subjects, but no significant difference was observed in the intake per body weight of proteins and Ca. It seems, possible that the low calorie, low protein, low fat, and low carbohydrate intake may be factors in the malnutritional condition of the patients with chronic pancreatitis. Analysis of covariance and principal component analysis showed that the body weight of the patients was closely correlated with decreases of caloric intake and intake of carbohydrate. The above results revealed that low body weight in patients with chronic pancreatitis was closely related to the decrease of calorie and carbohydrate intake, in addition to maldigestion and malabsorption of nutrients.

Adult↗
PubMed1994

Impaired hepatic function in segmental biliary obstruction demonstrated with a receptor-binding radiotracer.

A patient with cholangiocarcinoma underwent left-sided cholangiojejunostomy, and hepatic functional imaging with a receptor-binding radiotracer and SPECT was performed to evaluate the distribution of functional reserve. It revealed decreased accumulation in the regions with residual dilatation of the intrahepatic bile ducts, indicating several kinds of focal damage in hepatic function caused by segmental biliary obstruction. The radioligand may be useful in assessing regional hepatic function, and the high spatial resolution provided by SPECT appears to play an important role for this purpose.

Aged↗
PubMed1994

Abnormal sympathetic innervation of the heart in a patient with myotonic dystrophy detected with I-123 MIBG cardiac SPECT.

Iodine-123 MIBG is a norepinephrine analog which can be used to image the sympathetic innervation of the heart. The authors report a patient with myotonic dystrophy whose I-123 MIBG SPECT revealed accelerated washout of I-123 MIBG from infero-posterior and a part of lateral wall, although Tl-201 SPECT showed no abnormal finding. The authors conclude that I-123 MIBG can be more sensitive in detecting the cardiac abnormality than Tl-201 SPECT in this disease.

3-Iodobenzylguanidine↗
PubMed1994

Background correction in estimating initial renal uptake. Comparison between Tc-99m MAG3 and Tc-99m DTPA.

A gamma camera method with no blood sampling assesses differential renal function based on initial renal uptake, and requires background correction. The effect of background correction on estimates of initial renal uptake was compared on renograms using Tc-99m MAG3 and Tc-99m DTPA renographies in 14 patients. Renal counts for 2-3 minutes were obtained using three sets of regions of interest (ROIs): rectangular renal and subrenal background ROIs, rectangular renal and perirenal background ROIs, and hand-drawn renal and subrenal background ROIs. Correlations between estimates of initial renal uptake by the three methods were higher for Tc-99m MAG3 renography than for Tc-99m DTPA imaging, suggesting higher reproducibility in evaluating differential renal function using Tc-99m MAG3 renography and a gamma camera method. Although the ratio of counts in the suprarenal area to those in the subrenal area was significantly higher for the right side in the Tc-99m MAG3 study, probably because of hepatic activity, the relative uptake in the right kidney for Tc-99m MAG3 did not differ from that for Tc-99m DTPA. Initial uptake of Tc-99m MAG3 was well correlated with, and about threefold that, of Tc-99m DTPA. It was suggested that initial renal uptake of Tc-99m MAG3 may be an alternative to that of Tc-99m DTPA, with less dependence on background correction in evaluating differential renal function.

Gamma Cameras↗
PubMed1994

[Effects of voluntary wheel running on health indexes in rats with SRBC-induced inflammation].

The effects of voluntary running exercise on health indexes in rats were studied before and after Sheep Red Blood Cell (SRBC)-induced inflammation. Male Fischer rats (SPF) 8 weeks of age were housed in individual sedentary cages (sedentary group) or in individual wheel-running cages (exercise group) for 4 months. Then all rats were injected with 20% SRBC (0.5 ml/100g body weight) i.p. Voluntary running activity averaged 1408m/day, reached a peak (2913m/day) at the 25th day and waned over time, reaching a plateau at the 60th day (about 1000m/day). In spite of a significant increase in food intake (117%), exercising rats gained significantly less weight (93%) than sedentary rats at all times in experimental period. The exercise group also showed a significant decrease in the value of serum triglyceride (TG) and total cholesterol (T. CHO) (TG p < 0.0002, T. CHO p < 0.03). The hematocrit (Ht) and hemoglobin concentration (Hb) were higher in the exercised rats, and at 4 days after i.p. SRBC, the difference became statistically significant (Ht p < 0.0002, Hb p < 0.003). Thus, protective effects against the decrease of Ht and Hb were demonstrated in the exercised group. Perhaps this inflammation did not impair liver function severely; sedentary rats had normal or slightly higher levels of GOT and GPT. On the other hand, exercised rats had lower GOT and GPT. Significant differences were found between the groups (GOT, GPT p < 0.0001).

Animals↗
PubMed1994

[Effects of crowding on immune functions in mice].

The effects of several types of crowding on immune functions were studied in mice. This study consisted of two experiments. Experiment one: Male BALB/c mice were initially housed in groups of four mice per cage. After fourteen days of acclimation, the mice were randomly divided into three groups, Control (four mice per cage, control group), Crowd-I (four mice per small space) and Crowd-II (sixteen mice per cage). These conditions were maintained for seven days. The results of experiment one were as follows: (1) The percentage of lymphocytes in the blood of Crowd-II was significantly lower than that of Control (p < 0.05). (2) The percentage of neutrophils and the absolute number of neutrophils in blood of Crowd-II were significantly higher than in Control (p < 0.05). (3) Superoxide production activity (NBT reduction activity) of blood neutrophils in Crowd-II tended to be depressed, and phagocytic activity of neutrophils was significantly depressed in Crowd-II as compared with Control (p < 0.01). These results suggest that the complexity of interrelationships among mice caused by an increase in the number of animals per cage is a very important stress factor. Experiment two: Male BALB/c mice were initially housed in groups of five mice per cage. After fourteen days of acclimation, the mice were divided into three groups, Control (five mice per cage, control group), Crowd-(1) (five mice per cmall space) and Crowd-(2) (twenty mice per cage). In Control and Crowd-(1), the same mice were used as in the acclimation period. These conditions were maintained for seven days. In this period, on the second day, all the mice were injected intraperitoneally with sheep red blood cells (SRBC). The results of experiment two were as follows: (1) The specific humoral immune response to SRBC was investigated in terms of the number of PFC in the spleens and hemagglutination in sera, but significant differences were not found among the groups. (2) Plasma IgG levels in the Crowd-(1) were significantly higher than those in Control (p < 0.05). (3) Both superoxide production activity and phagocytic activity of neutrophils were significantly depressed in Crowd-(2) as compared with Control (p < 0.01, respectively), whereas each neutrophil function of Crowd-(1) tended to be enhanced as compared with Control.

Animals↗
PubMed1994

Decreased gastric secretory functions in diabetic patients with autonomic neuropathy.

A total of 37 subjects consisted of 10 healthy subjects (Group III), 15 diabetic patients without autonomic neuropathy (Group II), and 12 diabetic patients with autonomic neuropathy including gastroparesis in 6 cases (Group I). All three groups were comparable in age. In order to clarify the gastric function in diabetic patients with autonomic neuropathy, secretion of serum gastrin, gastric secretory function, endoscopic Congo red test of fundic glands, and coefficiency of variance of electrocardiographic beat-to-beat intervals (C.V. R-R) were examined. In Group I, 5 patients had hypergastrinemia, but its elevation was inhibited when an acid solution was injected into the stomach. Gastric secretion and C.V. R-R were markedly lower in Group I, compared with Groups II and III. In Group I, the area of fundic glands (parietal cells) was reduced considerably. The C.V. R-R was significantly correlated with fasting serum gastrin concentration and with maximal acid output. From these results, in diabetic patients with autonomic neuropathy (vagal neuropathy), gastric acid secretion in response to tetragastrin stimulation was lowered with a reduction in area of fundic gland distribution. Hypergastrinemia may reflect a negative feedback mechanism responding to decreased acidity of gastric content in the antrum.

Adult↗
PubMed1994

Diabetic retinopathy in Japanese patients with long-standing pancreatic diabetes due to calcifying pancreatitis.

This study analyzed the prevalence, aggravating factors (including duration of diabetes, glycemic control, body mass index, hypertension, serum total cholesterol, changes of ST on ECG and diabetic therapies) and characteristics of diabetic retinopathy in 75 patients with pancreatic diabetes resulting from calcifying pancreatitis. The patients were divided into three Groups: Group I (27 patients in whom diabetes was detected earlier than pancreatic stones), Group II (36 patients in whom diabetes and pancreatic stones were simultaneously detected) and Group III (12 patients in whom pancreatic stones were detected earlier than diabetes). The prevalence of retinopathy was dependent on the duration of diabetes as well as poor glycemic control. It was significantly (p < 0.01) higher among the patient with the duration of diabetes that was more than 5 years than that of the patients whose duration was less than 5 years. The prevalence of retinopathy in Group I (63%) was significantly (p < 0.05) higher than that in Group II (30.6%) and Group III (12.5%). Proliferative retinopathy was not found in any patients with a duration of diabetes less than 5 years, while it was found in 5 patients with a duration of more than 5 years (5 cases out of 31 patients). Diabetic retinopathy was correlated with the duration of diabetes and glycemic control, and was not linked to frequency of hypoglycemia and family history of diabetes. From the results above, we concluded that diabetic retinopathy in patients with pancreatic diabetes due to calcifying pancreatitis might be taken as evidence that such complications are primarily due to chronic hyperglycemia and the duration of diabetes mellitus rather than to genetic factors and other factors (body mass index, hypertension, serum total cholesterol and diabetic therapies).

Adult↗
PubMed1994

Octreotide decreases biliary and pancreatic exocrine function, and induces steatorrhea in healthy subjects.

A somatostatin analogue (SMS-201-995, hereinafter "octreotide") was s.c. administered to 5 healthy subjects under consecutive dripping of CCK-PZ (cholecystokinin-pancreozymin) and secretin (0.01 CHR U/kg/minutes), after inserting a Dreiling double tube into Treitz's ligament. Bile acid concentration, and bicarbonate and lipase excretions in duodenal juice were determined every 10 minutes up to 120 minutes and compared with controls. Moreover, octreotide (100 micrograms) was s.c. administered to 5 healthy subjects 30 minutes before meals for 7 days. Fecal fat and bile acid excretions before and after administration were determined. Bile acid concentration, and bicarbonate and lipase excretions in the octreotide group decreased to 1/3-1/4 that of controls. Bile acid concentration became 0 mM for 60 minutes. Fecal fat excretion increased; obvious steatorrhea occurred in 2 cases. Fecal bile acid excretion decreased to about 1/4. These results suggest that decreases in bile acid secretion should be considered, as well as pancreatic lipase and bicarbonate secretions, when fatty stool occurs after octreotide administration.

Adult↗
PubMed1994

[Current topics in infectious diseases].

In this symposium, we discussed the current aspects of the infectious diseases which have been becoming important problems in Japan. The following diseases were taken up the matter of MRSA infection, Helicobacter pylori infection, HIV-1 infection and HCV infection. 1) MRSA infection: Epidemiology of hospital acquired infection by MRSA and its management of prevention. 2) Helicobacter pylori infection: Evaluation of laboratory detection of H. pylori PCR and anti-H. pylori antibodies by ELISA. 3) HIV-1 infection: Epidemiology and prevention of HIV-1 infection and laboratory tests for the infection. 4) HCV infection: Genetic aspects of hepatitis C virus.

Communicable Disease Control↗
PubMed1993

[MR imaging of pituitary dwarfism].

Pituitary MR imaging was performed in 32 patients with clinically diagnosed pituitary dwarfism and 12 normal controls. The patients were divided into two groups according to the severity of pituitary dwarfism based on endocrinological data. The two patients with severe dwarfism showed transection of the pituitary stalk, ectopic posterior lobe and atrophy of the anterior lobe on MR imaging, while the 27 patients with mild dwarfism showed no abnormal MR findings of the pituitary gland. The former group corresponds to typical pituitary dwarfism and the latter to partial GH deficiency, which was recently proposed as another type of pituitary dwarfism. In conclusion, pituitary MR imaging may differentiate partial GH deficiency from typical (stalk-transected) pituitary dwarfism.

Adolescent↗
PubMed1993

The relationship between the effect of biphenylcarboxylic acid analogs on glyceride synthesis and conformation.

The inhibition of biphenylcarboxylic acid analogs on glyceride synthesis was studied in association with conformation of the chemicals. Chemicals used were benzoic acid substituted with phenyl, benzoyl and phenoxy groups, phenylphenyloxyacetic acid and p-phenylacetic acid. Twist angles were calculated by a molecular orbital method. Following oral administration of p-phenylbenzoic acid to the rats for 7 days, the decrease of the triglyceride synthesized from [14C]oleic acid was observed in the adipose tissue. The in vitro inhibitions on the formation of fatty acyl-CoA thioester were examined from the influence on the hippuric acid formation from [14C]benzoic acid using the rat liver slices. In the homologous series, high inhibition was observed in para and meta substituents. None, or low inhibitions of ortho-substituted chemicals were related to the steric hindrance of the phenyl ring against carboxyl groups. This hinderance was associated with conformation and with the geometrical relationship between substituted phenyl rings and carbon atoms of carboxylic acid. In the in vitro inhibition on overall formation of diglyceride and triglyceride from [14C]glycerol, o-phenylbenzoic acid showing no inhibition on hippuric acid formation did not show inhibition. However, other ortho-substituted chemicals showed higher inhibition in comparison with the inhibition on hippuric acid formation. The inhibition of para- and meta-substituted chemicals were higher than the corresponding values of ortho substituted compounds.

Animals↗
PubMed1993

Seasonal development of Leptotrombidium pallidum (Acari: Trombiculidae) observed by experimental rearing in the natural environment.

Engorged larvae of Leptotrombidium pallidum Nagayo, Miyagawa, Mitamura & Tamiya, the vector mite of scrub typhus in Japan, were reared by feeding them with fresh eggs of the collembolan Sinella curviseta Brook while confined in small plastic containers under natural conditions in a copse. The larvae were collected from wild rodents (Apodemus speciosus) in autumn 1985 and spring 1986. Adults were kept alive for 2 yr or longer. The larvae obtained in autumn became dormant in the cold winter season, and growth recommenced in the spring. Thus, the development of mites collected in April became synchronized with that of larvae obtained in the autumn. Most larvae developed into protonymphs in May, deutonymphs in June, tritonymphs in July, and adults in August. The females laid eggs in two consecutive summers. Some larvae collected in autumn were kept in a refrigerator until the following summer. They developed into deutonymphs, tritonymphs, or adults and then became dormant in the winter. Development restarted the next spring and all became adult by summer, when the females laid eggs. Under experimental conditions, all larvae are hatched in the autumn, unlike the natural situation in which two peaks of larval occurrence on wild rodents are observed in autumn and spring.

Animals↗