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Biomedical subjects

Y Hashiguchi

Publications and source records attributed to Y Hashiguchi.

At least 73 records · Page 4Linked to original sources
PubMed1995

Modulation of metabolic effects of morphine-6-glucuronide by morphine-3-glucuronide.

Modification of pharmacological effects of morphine by its glucuronides has been recently reported. Morphine-6-glucuronide (M6G) is a more potent opioid agonist than morphine, whereas morphine-3-glucuronide (M3G) has no opioid effects and has been suggested to be an antagonist of morphine's antinociceptive and respiratory depressive effects. This study addressed the metabolic effects of direct central nervous system administration of M3G and its interaction with the hyperglycemic effects of M6G. Hormonal and whole body glucose metabolic effects of M3G, M6G, and M3G + M6G ICV administration were studied in conscious unrestrained chronically catheterized rats. Whole body glucose kinetics were assessed with a primed constant intravenous infusion of 3[3H]glucose in rats injected intracerebroventricularly (ICV) with H2O (5 microliters), M3G (1 microgram), M6G (1 microgram), or M3G (1 microgram) + M6G (1 microgram). A significant rise in plasma glucose level was observed after ICV injection of M6G (28%), and M3G + M6G (41%), but not after M3G as compared to time-matched H2O control. Early increases in the rate of glucose appearance (Ra) and whole body glucose utilization (Rd) were observed (58% and 48%, respectively) 30 min after M3G + M6G administration, whereas the increases after M6G injection were progressive and reached values 47% higher than basal 180 min after injection. M3G administration enhanced the M6G induced increase in plasma glucose level (+21%), Ra (+29%), Rd (+26%), and plasma lactate level (+21%). Though no significant hormonal change was observed in H2O, M3G, and M6G injected animals, the combination of M3G + M6G resulted in a significant increase in circulating catecholamine levels with no alterations in plasma corticosterone, insulin, and glucagon.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Differential hemodynamic, metabolic and hormonal effects of morphine and morphine-6-glucuronide.

Although the hyperglycemic effect of morphine has been previously described, it is not clear whether this is the result of increased glucose production and/or decreased glucose utilization and if this metabolic effect is lost with glucuronidation. This study assessed the hemodynamic (heart rate; HR and mean arterial blood pressure; MABP), hormonal and whole body glucose metabolic effects of morphine (MOR) and its metabolite morphine 6-glucuronide (MOR-6G) in conscious unrestrained chronically catheterized rats. Whole body glucose kinetics were assessed with a primed constant intravenous infusion of [3-3H]glucose in rats infused i.c.v. with H2O (Con; 5 microliters/h), MOR (80 micrograms/h) or MOR-6G (1 microgram/h) for a total of 4 h. MOR administration resulted in a significant 20% elevation in HR and no change in MABP. MOR-6G produced a 14% increase in HR and no change in MABP. A significant rise in plasma glucose (+23%), hepatic glucose production (Ra; +27-61%) and whole body glucose utilization (Rd; +31-61%) was also observed within 60 min of MOR administration. I.c.v. MOR-6G resulted in hyperglycemia (+60%), stimulation of glucose Ra (+60%) and glucose Rd (+50%). No significant alterations were noted in hemodynamic, metabolic and hormonal parameters of H2O infused rats. I.c.v. MOR resulted in a significant increases in epinephrine (2-fold), norepinephrine (50%), corticosterone (97%) with no alterations in plasma insulin and glucagon. I.c.v. MOR-6G resulted in more marked elevations in norepinephrine (5-fold), epinephrine (7-fold) and similar elevation in corticosterone (99%) and modest elevation of glucagon (40%).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Artificial endocrine pancreas and optimal blood glucose regulation in diabetic patients--from bedside-type to wearable-type.

The artificial endocrine pancreas is a feedback control system regulating insulin delivery on a minute-by-minute basis according to the measured blood glucose levels. The bedside-type artificial endocrine pancreas has been proven to be useful not only as a therapeutic tool for diabetes mellitus but also as an elegant research tool for investigating the pathophysiology of the disease. With significant advances in the development of a subcutaneous tissue glucose monitoring system, the wearable-type artificial endocrine pancreas has been applied to diabetic patients. With this system, perfect glycemic control can be obtained for longer periods in ambulatory diabetic patients. The trend in the development of the artificial endocrine pancreas is now directed to implantable devices. Much efforts have been conducted to realize these devices.

Blood Glucose↗
PubMed1994

Histopathological and electron microscopical features of skin lesions in a patient with bartonellosis (verruga peruana).

Chronic verruga nodules taken from a patient with Bartonellosis (verruga peruana) were studied. Histologically, specimens of all the verruga nodules had features consistent with granulomatous lesions with extensive infiltration of various types of cells along with the proliferation of capillaries. The sections were predominantly infiltrated with neutrophils and endothelial cells; histiocytes, plasma cells, lymphocytes and mast cells were also visible to some extent. The blood vessels were dilated, and many rounded and swollen endothelial cells were located peripherally; a huge number of neutrophils invaded the vessels. Electron microscopically, large number of organisms were seen in different stages of the life cycle in the stroma. Furthermore, organisms were regularly seen either in close contact or existing inside the cytoplasm of neutrophils, suggesting the phagocytic role of these cells. No organism was found inside any endothelial cells or histiocytes.

Bartonella Infections↗
PubMed1994

Development of a miniaturized glucose monitoring system by combining a needle-type glucose sensor with microdialysis sampling method. Long-term subcutaneous tissue glucose monitoring in ambulatory diabetic patients.

OBJECTIVE: To develop a reliable and practical glucose monitoring system by combining a needle-type glucose sensor with a microdialysis sampling technique for long-term subcutaneous tissue glucose measurements. RESEARCH DESIGN AND METHODS: A microdialysis Cuprophan hollow-fiber probe (inner diameter, 0.20 mm; length, 15 mm) was perfused with isotonic saline solution (120 microliters/h) and glucose concentrations in the dialysate were measured by a needle-type glucose sensor extracorporeally. This system was tested both in vitro and in vivo. Subcutaneous tissue glucose concentrations were then monitored continuously in 5 healthy and 8 diabetic volunteers for 7 to 8 days. A hollow-fiber probe was inserted into the abdominal subcutaneous tissue. RESULTS: This monitoring system achieved excellent results in vitro. Subcutaneous tissue glucose concentrations were measured in a wide range from 1.7 to > 27.8 mM glucose, with a time delay of 6.9 +/- 1.2 min associated with a rise in glucose and 8.8 +/- 1.6 min with a fall in the glucose level (means +/- SE). The overall correlation between subcutaneous tissue (Y) and blood (X) glucose concentration was Y = 1.08X + 0.19 (r = 0.99). The subcutaneous tissue glucose concentration could be monitored precisely for 4 days without any in vivo calibrations and for 7 days by introducing in vivo calibrations. CONCLUSIONS: Glycemic excursions could be monitored precisely in the subcutaneous tissue by this microdialysis sampling method with a needle-type glucose sensor in ambulatory diabetic patients.

Adult↗
PubMed1993

Complete avulsion of the papilla of Vater and gastroduodenal artery due to blunt abdominal trauma: report of a case.

A case of traumatic avulsion of the papilla of Vater and gastroduodenal artery successfully treated by pancreaticoduodenectomy is presented herein. The mechanism of this rare injury appeared to be a shearing force applied to the common bile duct and gastroduodenal artery. Thus, when the liver is driven cephalad by compression of the abdomen and by the deceleration force, the common bile duct and gastroduodenal artery are avulsed from the fixed duodenum and pancreas. The mechanism of this rare injury is postulated on the basis of operative and histological findings. Our case is thought to be the first of traumatic avulsion of the papilla of Vater and gastroduodenal artery to be reported in Japan.

Abdominal Injuries↗
PubMed1993

Noninvasive measurement of blood glucose concentrations by analysing Fourier transform infra-red absorbance spectra through oral mucosa.

Whether Fourier transform infra-red spectroscopy with an attenuated total reflection prism could be applied for noninvasive glucose measurement through oral mucosa was evaluated. As a result, the same absorbance peak at 1033 cm-1 as in glucose aqueous solution was found in the absorbance spectra through mucous membrane. However, these glucose specific peaks were interfered with by the baseline drifts owing to prism attachment and the background spectra from body constituents other than glucose. Therefore, to eliminate these interferences, the calibration curve between the second derivatives of the absorbance peak at 1033 cm-1 and those at 2920 cm-1 was calculated (r = 0.910). By using this calibration curve, the spectral changes due to prism attachment were first eliminated. Secondly, by obtaining the second derivative of the difference between the postprandial absorbance peak and the fasting sample as a characteristic of an individual, high correlations between the corrected second derivatives of absorbance spectra through the mucous membrane of the lip at 1033 cm-1 and the increases in blood glucose concentrations above fasting levels were observed (r = 0.910). In conclusion, it was suggested that Fourier transform infra-red spectroscopy could be useful for noninvasive monitoring of glucose through oral mucosa.

Blood Glucose↗
PubMed1993

Molecular karyotype characterization of Leishmania panamensis, Leishmania mexicana, and Leishmania major-like parasites: agents of cutaneous leishmaniasis in Ecuador.

Molecular karyotypes of Leishmania isolates from patients with cutaneous leishmaniasis in Ecuador were analyzed by pulsed-field gel electrophoresis (PFGE) and Southern blot hybridization. The DNA karyotypes of L. major-like parasites were similar between two human isolates from a lowland coastal and a highland Andean region, but were apparently different from those of eleven World Health Organization reference strains including L. major. The smallest chromosome of 240 kilobases in L. major-like parasites was found to belong to the 715-class of small linear chromosomal DNAs, which have been shown to appear in some lines of Leishmania. Chromosome banding patterns of L. mexicana isolates exhibited a novel, ordered, chromosomal ladder, and were identical among four human isolates and one canine isolate from a restricted geographic region in the Andes. On the other hand, minor chromosome size polymorphisms were observed among three L. panamensis isolates from different endemic regions near the Pacific Coast. Chromosomal locations of dihydrofolate reductase-thymidylate synthetase and P-glycoprotein genes revealed further differences in chromosomal organizations among these Leishmania species in Ecuador. These results indicate that karyotype analysis by PFGE is useful for epidemiologic studies of leishmaniasis in Ecuador.

Animals↗
PubMed1992

Phlebotomine sandfly species in Paraguay and their infection with Leishmania.

Nine species of sandflies, Lutzomyia (Nyssomyia) whitmani (Antunes and Countinho), Lutzomyia (Nyssomyia) intermedia (Lutz and Neiva), Lutzomyia (Psathyromyia) shannoni (Dyar), Lutzomyia migonei (Franca), Lutzomyia (Pintomyia) fischeri (Pinto), Lutzomyia (Pintomyia) pessoai (Countinho and Barretto), Lutzomyia cortelezzii (Brethes), Lutzomyia walkeri (Newstead) and Lutzomyia (Trichopygomyia) longispinus (Mangabeira), were caught, by human bait and Shannon trap, in four areas of Paraguay hyper-endemic for human leishmaniasis. Lutzomyia whitmani and L. intermedia were the predominant species. All the species collected were found to be anthropophilic. Hindgut infections with leishmanial promastigotes were observed in only one (0.38%) of the 266 L. whitmani dissected. No L. intermedia were found infected, giving an overall infection rate of one (0.16%) of 615 flies dissected. The results indicate a very low rate of natural infection in endemic areas of Paraguay.

Animals↗
PubMed1992

Effects of a new dihydropyridine derivative, FRC-8653, on blood pressure in conscious spontaneously hypertensive rats.

Antihypertensive effects of FRC-8653, a new 1,4-dihydropyridine derivative, and its combined effects with an angiotensin converting enzyme (ACE) inhibitor, a diuretic, and a beta-adrenergic blocking agent were examined in conscious spontaneously hypertensive rats (SHR). When administered intravenously to SHR (10, 30 micrograms/kg), FRC-8653 lowered blood pressure more slowly and sustained it longer than nifedipine and nicardipine. Consecutive once-daily administrations of FRC-8653 to SHR (3 mg/kg, p.o.) produced a stable reduction of blood pressure throughout the experimental period of 29 d. When blood pressure was continuously measured for 24 h in conscious unrestricted SHR, orally administered FRC-8653 produced a long-lasting reduction in blood pressure. When concomitantly used with atenolol (30 mg/kg, p.o.), the antihypertensive effect of FRC-8653 was augmented in both potency and duration. However, simultaneous administration of captopril (30 mg/kg, p.o.) or hydrochlorothiazide (2.5 mg/kg, p.o.) did not modify the antihypertensive effect of FRC-8653.

Animals↗
PubMed1992

In vitro and ex vivo Ca-antagonistic effect of 2-methoxyethyl(E)-3-phenyl-2-propen-1-yl(+/-)-1,4-dihydro-2,6-dimethyl- 4-(3- nitrophenyl)pyridine-3,5-dicarboxylate (FRC-8653), a new dihydropyridine derivative.

The characteristics of calcium antagonism and vascular effect of 2-methoxyethyl(E)-3-phenyl-2-propen-1-yl(+/-)-1,4-dihydro-2,6-dime thyl-4-(3- nitrophenyl)pyridine-3,5-dicarboxylate (FRC-8653) were investigated. FRC-8653 inhibited an increase in intracellular free calcium concentration during membrane depolarization in PC12 cells. FRC-8653 also inhibited the specific binding of 3H-nitrendipine to cardiac membranes, in a similar manner to nifedipine and nicardipine. FRC-8653 inhibited KCl- and CaCl-induced contractions in isolated rabbit aorta, but failed to affect norepinephrine-induced contraction. The vasorelaxing effect of FRC-8653 in rabbit aorta developed more slowly than those of nifedipine and nicardipine. In ex vivo experiment, the inhibitory effect of orally administered FRC-8653 against KCl-contraction in rat aorta lasted longer than that of nifedipine. These findings suggest that FRC-8653 dilates blood vessels by blocking calcium influx via dihydropyridine-sensitive, voltage-dependent calcium channels and that the vascular effects are slow in development and long in duration.

Animals↗
PubMed1992

Spectroscopic quantitative analysis of blood glucose by Fourier transform infrared spectroscopy with an attenuated total reflection prism.

As an alternative way of long-term glycemic monitoring, the glucose measurement by analyzing Fourier transform infrared absorbance spectra with an attenuated total reflection prism has been developed. In glucose aqueous solution, glucose has characteristic absorptions at the wave numbers of 1033 and 1080 cm-1 and the absorption intensities are proportional to glucose concentrations. In serum and whole blood samples, however, red blood cell corpuscles, serum albumin and serum gamma-globulin interfere with the absorbance spectra of glucose and shift the base line upward significantly. Therefore, to eliminate these interferences in serum and whole blood samples, the feasibility of the calibration curves obtained by using difference absorbance spectra with those of fasting samples was studied. As a result, highly significant correlations between glucose concentrations estimated by Fourier transform infrared spectroscopic method and those measured by glucose oxidase method were obtained (r = 0.981 and 0.989 for serum and whole blood samples, respectively). From these experiments, it was concluded that by infrared spectroscopy glucose concentrations in the serum and whole blood samples could be measured quantitatively or monitored if the base line drifts and interferences were subtracted.

Blood Glucose↗
PubMed1991

Monthly variation in natural infection of the sandfly Lutzomyia ayacuchensis with Leishmania mexicana in an endemic focus in the Ecuadorian Andes.

In order to collect information on the role of Lutzomyia ayacuchensis in the transmission of leishmaniasis in a newly discovered Andean endemic focus in Ecuador, a longitudinal field study was carried out over 13 months. Monthly dissections were made of a minimum of 200 anthropophilic sandflies, collected at night during the month. A total of 2600 flies was separated from a small number of Lu. osornoi, another anthropophilic species in the area, and dissected; 95 (3.65%) were naturally infected with Leishmania mexicana promastigotes. The parasites were always located in the sandfly midgut. The current study revealed a marked monthly variation both in natural infections with Leishmania and in biting activity of sandflies in the endemic area, demonstrating a high transmission rate during the period from the early rainy season to the early or mid dry season (February to July).

Animals↗
PubMed1991

Experimental lethal infection of Leptospira interrogans in mice treated with cyclophosphamide.

After preadministration of cyclophosphamide (300 mg/kg), BALB/c mice were lethally infected with Leptospira interrogans serovar lai and a virulent strain of Leptospira interrogans serovar copenhageni, and leptospiral cells were detected in both kidneys of infected mice by indirect immunofluorescent assay. Nonpathogenic leptospirae, Leptospira biflexa serovar patoc, Leptonema illini, and an avirulent strain of L. interrogans serovar copenhageni, were not parasitic to the mice treated with cyclophosphamide. The cyclophosphamide-treated mice were protected from the homologous leptospiral infection by passive immunization with anti-leptospiral monoclonal antibody or with rabbit antiserum and by active immunization with lyophilized organisms or with protective antigen. The results of active immunization in mice treated with cyclophosphamide agreed well with those in nontreated hamsters, which were sensitive to the organisms. Furthermore, these experiments were reproducible with any lot of cyclophosphamide used. These results indicated that cyclophosphamide-treated mice can be used in the experimental infection of Leptospira in place of hamsters or guinea pigs.

Animals↗
PubMed1991

Andean leishmaniasis in Ecuador caused by infection with Leishmania mexicana and L. major-like parasites.

Between 1986 and 1988, epidemiologic studies were carried out in a small rural community in an Andean region of Ecuador, where cutaneous leishmaniasis is highly endemic. A total of 25 human cases, positive for Leishmania parasites by culture and/or smear, were examined. Fourteen of the cases were in infants less than one year of age, suggesting intradomiciliary transmission of the disease. Clinically, many of these cases were similar to descriptions of "uta," a form of cutaneous leishmaniasis which occurs in Andean regions of Peru and is reported caused by L. peruviana. Of the 11 positive cultures obtained from human cases in the present study, eight were identified by molecular characterization as L. mexicana and three were identified as L. major-like. Two additional isolates of L. mexicana were also made from an infected dog and from a sand fly, Lutzomyia ayacuchensis, living in the region, thus implicating the latter species as possible reservoir and vector, respectively, of L. mexicana in this highland community. The significance and validity of recent isolates of L. major-like parasites from the New World are also discussed.

Animals↗
PubMed1991

An artificial endocrine pancreas--problems awaiting solution for long-term clinical applications of a glucose sensor.

The artificial endocrine pancreas is a feedback controlled system regulating insulin delivery on a minute-by-minute basis according to measured blood glucose levels. The bedside-type artificial endocrine pancreas has been proven to be useful not only as a therapeutic tool for diabetic patients but also as an elegant research tool for investigating the pathophysiology of the disease. Recently, a wearable-type, closed-loop system has been developed, of which the breakthrough was the establishment of a needle-type glucose sensor. However, for the long-term clinical use of needle-type glucose sensors, several obstacles remain to be solved, such as oxygen dependency, biocompatibility of the membrane, etc. The most promising method for the non-invasive determination of blood glucose is infrared spectroscopy. The trend in the development of a closed-loop glycemic control system which enables perfectly physiological glycemic regulation on a long-term basis is directed to an implantable device. Much research is being conducted to realize such devices.

Alginates↗
PubMed1991

A review of leishmaniasis in Ecuador.

This article briefly reviews current knowledge about leishmaniasis in Ecuador--proceeding from 1920, when the first human case was described, to the present. Regarding basic conditions, it appears that 14 of Ecuador's 20 provinces have endemic leishmaniasis. Nationally, over 4,000 cases were registered in the 1983-1986 period. Of 260 cases cited in the literature from 1920 through 1987, 240 (92.3%) were said to involve cutaneous forms of the disease and 18 (6.9%) mucocutaneous ones. Only one case each of visceral and diffuse cutaneous leishmaniasis was reported in 1920-1987, and neither of these has been confirmed. Various Leishmania strains isolated by the authors from wild animals and man are currently being studied. To date, tests employing isoenzyme electrophoresis and monoclonal antibodies have identified some of the isolated strains as L. amazonensis and L. panamensis. At present it seems evident that a detailed study of leishmaniasis transmission in Ecuador is needed in order to develop a plan for future control of the disease. Survey work directed at identifying the particular Leishmania varieties prevalent in the country's different endemic areas is also needed, as is research on the sandfly vectors and animal reservoirs of the disease.

Animals↗