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Biomedical subjects

K Kamimura

Publications and source records attributed to K Kamimura.

At least 55 records · Page 3Linked to original sources

Blockade of beta-adrenoceptor in control of blood pressure in fowl.

Several avian species show elevated blood pressure (BP) and spontaneous atherogenesis in the aorta and other large arteries. The BP appears to be influenced by age, sex (higher in males), environment, and diet in some species. We reported previously that mean aortic pressure and heart rate, but not plasma renin activity (PRA), of conscious female domestic fowl were markedly reduced by propranolol. In the present study, we aimed to determine in conscious roosters whether 1) hypotension evoked by atenolol or practolol, which selectively inhibit cardiac beta-receptors in mammals, is more potent than that evoked by propranolol, and 2) the renin-angiotensin (ANG) system and/or catecholamines are involved in beta-adrenoceptor antagonist-induced hypotension. Mean arterial pressure (171.2 +/- 3.5 mmHg) and heart rate (281 +/- 4 beats/min) of chronically cannulated roosters (n = 38) were markedly reduced by acute infusion or repeated injections (14 days) of propranolol, atenolol, or practolol, but not by SQ-14,225 (ANG-converting enzyme inhibitor) or [Sar1, Thr8]ANG II (nonselective ANG receptor antagonist). None of the beta-adrenoceptor blockers, however, showed cardioselectivity. The resting PRA of conscious roosters (1.27 +/- 0.09 ng.ml-1.h-1, n = 38) was low and did not change significantly after chronic or acute treatment with beta-adrenoceptor blockers except for a slight decrease induced by practolol. PRA increased after SQ-14,225. The plasma levels (pg/ml) of norepinephrine (701.9 +/- 76.0), epinephrine (337.2 +/- 57.1), and dopamine (299.1 +/- 39.0) of conscious roosters were further increased by propranolol. Practolol also increased dopamine significantly.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗

A comparison of the antihepatotoxic activity between glycyrrhizin and glycyrrhetinic acid.

A comparison of antihepatotoxic activities between glycyrrhizin (18 beta-GL) and its genuine aglycone, glycyrrhetinic acid (18 beta-GA), was carried out using in vivo and in vitro assay methods. The oral administration of 18 beta-GA at 1, 24, and 48 h before D-galactosamine (GalN) treatment significantly reduced the increase of serum transaminase activities 24 h after GalN treatment, whereas 18 beta-GL did not inhibit the increase of serum transaminase activities. The intraperitoneal administration of 18 beta-GA 1 h before GalN treatment restored the increase of serum transaminase activities with lower doses than 18 beta-GL. In CCl4-induced cytotoxicity of primary cultured rat hepatocytes, 18 beta-GA protected the CCl4-induced leakage of transaminase at doses of 5 to 50 micrograms/ml, whereas 18 beta-GL inhibited slightly the leakage at a dose of 1000 micrograms/ml. In the same way, 18 alpha-GA, the alpha-isomer of 18 beta-GA, reduced the CCl4-induced cytotoxicity more strongly than 18 alpha-GL. Furthermore, the adsorbability of 18 alpha, beta-GA on primary cultured rat hepatocytes was higher than that of 18 alpha, beta-GL. These results suggest that 18 alpha, beta-GA is a more potent antihepatotoxic agent than 18 alpha, beta-GL, and that the potency of the antihepatotoxic compounds parallels their adsorbability in hepatocytes.

Animals↗

Prevalence of intestinal helminthic infections in Kao District, north Halmahera, Indonesia.

A parasitological survey was conducted on the inhabitants of six villages of Kao District, Halmahera Island, North Maluku, Indonesia, in July 1993. A total of 422 fecal samples were examined by using Kato-Katz thick smear, modified Harada-Mori culture and formalin ether concentration techniques. Seven nematode species, ie Ascaris lumbricoides, Trichuris trichiura, Necator americanus, Ancylostoma duodenale, Strongyloides stercoralis, Enterobius vermicularis and unidentified rhabditoids of free-living nature, were detected. Trematode and cestode infection was not proven. Necator americanus was the predominant species of hookworm. Soil-transmitted nematode infections were highly prevalent. Among the young inhabitants aged less than 15, positive rates of Ascaris, Trichuris and hookworm infections were 32.7, 52.7 and 68.6%, respectively. Among the people aged 15 or more, the positive rate for hookworm (85.9%) was much higher than that for Ascaris and Trichuris (13.5 and 40.5%, respectively). Egg count revealed that more than 90% of inhabitants with Trichuris or hookworm had light infections. The latrines in the surveyed area seemed to have only limited effects on the improvement of the parasitological status because the prevalence of Trichuris infections was much higher in a village where most houses were provided with latrines. These conflicting conditions were considered to have been caused by many factors including the inadequate structure of the latrines.

Adolescent↗

Intestinal parasitic infections in Campalagian district, south Sulawesi, Indonesia.

Intestinal parasitic infections were surveyed in the inhabitants of 3 coastal and 2 inland villages of Campalagian District, South Sulawesi, Indonesia, in July 1992. A total of 398 fecal samples were examined by using Kato-Katz thick smear, Harada-Mori culture and agar-plate culture techniques. Protozoan cysts were examined by formalin ether concentration technique on 380 fecal samples. Soil-transmitted helminth infections were highly prevalent with the overall positive rates as follows: Ascaris lumbricoides 25.3%, Trichuris trichiura 59.3%, hookworm 68.3% and Strongyloides stercoralis 2.3%. Eight species of protozoan were detected with the overall prevalence as follows: Entamoeba histolytica 10.9%, E. hartmanni 16.3%, E. coli 31.9%, Endolimax nana 12.5%, Iodamoeba buetschlii 5.4%, Giardia lamblia 4.6%, Chilomastix mesnili 0.8% and Blastocystis hominis 18.0%. In the inland villages, prevalence of hookworm infection was higher than Ascaris and Trichuris infections, while in the coastal villages Trichuris infection was predominant. Egg count revealed that the infection level was light in most of the hookworm and Trichuris carriers. Prevalence of lavatories among houses appeared to be inversely proportional to the prevalence of hookworm infection. Meanwhile, the incomplete structure of the lavatories might result in contamination of environment with Ascaris and Trichuris eggs. Harada-Mori culture was the most efficient method in the detection of hookworm infection compared to other techniques. Both Necator americanus and Ancylostoma duodenale were found in all villages, but the former was the predominant species. An adult pinworm was detected by agar-plate culture of feces. Two types of pinworm males, corresponding to Enterobius vermicularis and E. gregorii, were observed.

Adolescent↗

Plasmodium berghei: sporozoites are sensitive to human serum but not susceptible host serum.

Human complement was activated by rodent malaria, Plasmodium berghei, sporozoites through the alternative pathway, as revealed by C3 deposition on sporozoites using the fluorescent antibody technique. Sporozoites exposed to fresh human serum decreased in infectivity to HepG2 cells, but those exposed to heated or C3-deficient human serum showed normal infectivity to HepG2 cells. In contrast, C3 deposition was not observed on the sporozoites treated with mouse or rat serum even in the presence of specific polyclonal anti-sporozoite antibody. However, following treatment with trypsin (250 micrograms/ml), 81% of salivary gland sporozoites and 49% of oocyst sporozoites became reactive with mouse serum, and reactive sporozoites deposited mouse C3 on their surface in the presence of 30 mM EGTA and 1 mM Mg2+ without antibody. Concomitantly some sporozoites lost reactivity to anti-circumsporozoite protein monoclonal antibody. These results suggest that P. berghei sporozoites possibly express surface molecules that regulate the complement activation pathway of susceptible hosts but not of nonhosts, and that the putative structures consist of protease-sensitive molecule(s) which are closely associated with the circumsporozoite protein.

Animals↗

Cyclical transmission of Plasmodium berghei (Coccidiida: plasmodiidae) by Anopheles omorii (Diptera: Culicidae).

Anopheles omorii, a tree-hole breeding anopheline collected in Japan, transmitted a rodent malaria, Plasmodium berghei ANKA strain, in the laboratory. Mice with 0.2-15% parasitemia, 0.01-1.5% gametocytemia, and 0.001-0.5% exflagellations were used as infective hosts. Oocyst numbers ranged from 2 to 171 (mean 44) on the midgut 8-16 d after the blood meal. Several to hundreds of sporozoites were detected in the salivary glands 14 d after feeding. The mosquitoes were infective to mice from 13 to 40 d after feeding. An. omorii occurs naturally at temperatures less than 25 degrees C and therefore is a suitable laboratory vector for the cyclic transmission of P. berghei, a malaria parasite that completes sporogony at 18-21 degrees C.

Animals↗

[Effects of smoking and drinking habits and vitamin A intake on serum concentrations of beta-carotene and retinol].

Serum samples from 341 males aged 10 to 59 years were obtained and stored at -40 degrees C until examined for retinol and beta-carotene concentrations by HPLC, and their relationships to smoking habit, alcohol drinking habit and vitamin A intake were studied. In univariate analysis the serum beta-carotene level was significantly lower in the smokers than in the non-smokers (smokers: 4.6 micrograms/dl, non-smokers: 7.1 micrograms/dl, p less than 0.01) and lower in the drinkers than in the non-drinkers (drinkers: 4.6 micrograms/dl, non-drinkers: 7.3 micrograms/dl, p less than 0.01). The serum retinol level was not different by smoking habit but was higher in the drinkers than in the non-drinkers (drinkers: 80.4 micrograms/dl, non-drinkers: 67.0 micrograms/dl, p less than 0.01). Serum beta-carotene was higher in the group with a greater intake of vitamin A of vegetable origin (6.1 micrograms/dl) than in the group with a smaller intake of it (4.7 micrograms/dl) (p less than 0.01), but serum retinol was not different by the amount of vitamin A intake of animal food origin. To estimate the respective effects and interactions of the above factors on serum beta-carotene and retinol levels by adjusting for the confounding effects of age, serum total cholesterol, HDL-cholesterol and triglyceride, analysis of covariance was performed. For serum beta-carotene, smoking habit (p less than 0.01), drinking habit (p less than 0.01) and the amount of vitamin A intake of vegetable food origin (p less than 0.05) had significant main effects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Epidemiological study of malaria in north Sulawesi, Indonesia by fluorescence and Giemsa staining.

An epidemiological study of malaria infection was conducted in the Likupang District, Minahasa Regency, North Sulawesi Province, Indonesia, during August 2-15, 1991. In this study, 510 people of six villages, representing ages between 1 month to 84 years cooperated voluntarily. Blood smears stained with Giemsa and acridine orange (AO), revealed 33 and 83 malaria parasite positives respectively. This significant difference was due particularly to the fact that AO staining examined under either a daylight- or halogen-illuminated microscope equipped with interference filters was sensitive to detect low-density parasitemia in many subjects previously diagnosed negative by Giemsa staining in the field. The low malaria prevalence obtained by Giemsa staining may have been attributable to the lack of standard-quality diagnostic tools in the field or inadequate observation of the slides. In both staining methods, Plasmodium falciparum was found to be the predominant species, while the remainings were P. vivax or a mixture of both. Subjects infected with P. vivax revealed higher density of parasitemia and gametocytemia than those with P. falciparum.

Acridine Orange↗

Intestinal parasitic infections in Likupang, North Sulawesi, Indonesia.

A parasitological survey was conducted on the inhabitants of 6 villages of Likupang, Minahasa Peninsula, North Sulawesi, Indonesia, in August 1991. A total of 419 fecal samples were examined by using direct smear, flotation, formalin ether concentration, Harada-Mori culture and agar-plate culture techniques. Five nematode and 7 protozoan parasites were detected, while trematode and cestode infection was not observed. Soil-transmitted nematode infections were predominant. Among the younger inhabitants aged less than 15, positive rates of Ascaris, Trichuris and hookworm infections were almost same, namely 45.7, 45.3 and 47.7%, respectively. Among the elder people aged 15 or more, positive rate of hookworm infection (89.4%) was much higher than Ascaris and Trichuris infections (19.3 and 26.1%, respectively). Village to village differences in parasite prevalence, probably due to socio-economic and sanitary-environmental differences were observed. Both Necator americanus and Ancylostoma duodenale were detected. The agar-plate culture was proved to be an efficient method for detection of hookworm as well as Strongyloides stercoralis.

Adolescent↗

[Circadian variations of sudden death].

Characteristics of the circadian variation for sudden death (SD), were studied by analyzing summary death certificates for the period of 1984 to 1986 in Niigata prefecture. SD was defined as death within 2 hours of onset of underlying cause (n = 4,362), and the time of onset of the cause was determined by subtracting the "time elapsed until death" from the "time of death." The periodicity for time of onset of the cause was analyzed in groups stratified by year, season, sex and age with Rogers' method utilized to check the statistical significance of the periodicity. SD, as a whole, showed a statistically significant circadian variation with a low incidence during 0 to 4 A.M. and a high incidence during 6 to 8 A.M. and 6 to 8 P.M. By season, no significant circadian variation was seen in the summer unlike for other seasons. When analyzed by age group, no significant circadian variation in SD was seen for the young to middle aged group (15-54 years old). On the other hand, there was a significant circadian variation for the senior (55 to 74 years old) and the elderly group (75 years old or older) with a low incidence during 0 to 4 A.M. and high incidence during 6 to 12 A.M. and 6 to 8 P.M.. For the old age group, the number of the cases increased so remarkably as to form an evening peak. The percentage of SD for young to middle cases was higher in the summer than in the other seasons which may be the reason for absence of significant circadian variation in the summer.

Adolescent↗

Distribution of actin-filament bundles in myoid cells, Sertoli cells, and tunica albuginea of rat and mouse testes.

Frozen sections of the rat and mouse testes were stained with either FITC-phalloidin or NBD-phallacidin and viewed with conventional fluorescence and confocal laser microscopes in order to demonstrate the arrangement of actin-filament bundles in myoid cells, Sertoli cells and tunica albuginea. Myoid cells are rich in actin-filament bundles crossing at right angles. These bundles running in different directions can also be visualized by means of electron microscopy. Nerve fibers occur in the vicinity of myoid cells, suggesting a neural control of the cell. At Sertoli cell junctions actin filaments occur at the circumference of the cell, where they show a honeycomb pattern. The ratio of the number of Sertoli cells per myoid cell can be calculated by means of confocal microscopy; this technique may provide a new parameter for determining spermatogenic activity. In the tunica albuginea of the juvenile mouse testis, actin filaments are arranged in an alternate fashion.

Actins↗

Penetration of the mosquito midgut wall by the ookinetes of Plasmodium yoelii nigeriensis.

The penetration route of ookinetes of Plasmodium yoelii nigeriensis in the midgut of a mosquito, Anopheles omorii, was investigated by electron microscopy. Within 15-18 h after an infective blood meal, ookinetes could be seen in the midgut lumen, in the process of entering the midgut wall, or lodged between the basement membrane and the basal lamina. The morphology of the ookinetes and their transformation into early oocysts were found to be similar to those previously reported. Ookinetes penetrated the midgut wall by the intercellular route; however, the intracellular occurrence of the parasite was also observed. Vacuoles appeared around the penetrating ookinetes during the penetration process, but no change in the electron density of the rhoptry-microneme complex was noted.

Animals↗

Coronary arterial calcification in Kawasaki disease.

The purpose of this paper is to describe the clinical characteristics and significance of the coronary arterial calcification due to Kawasaki disease (KD), based on our five patients. The coronary arterial lesions (CAL) were in segments 1, 2, 5, 6 and 11 according to the classification of the American Heart Association. The interval from the onset to the first appearance of coronary calcification was 17 months to 61 months. Progression of CAL into coronary arterial stenosis or myocardial infarction occurred in all five patients. In the comparative study between the patients with calcified CAL and those with non-calcified CAL, the maximal size of CAL of the former was 8 mm or larger in contrast with that of the latter (less than 8 mm). It is concluded that coronary arterial calcification is one of the important signs which suggest the presence of the advanced CAL in the follow-up of children with a history of KD.

Calcinosis↗

Significance of elevated serum LDH (lactate dehydrogenase) activity in atopic dermatitis.

Serum lactate dehydrogenase activity (LDH) was elevated in most cases with the severe type of atopic dermatitis (AD). We examined whether LDH correlated specifically with the clinical courses and the severity of AD skin eruptions. Blood eosinophil numbers (Eo), LDH and its isoenzymes, and serum IgE (IgE) levels in eighty patients with AD were measured before and after treatment. In improved groups, Eo and LDH decreased or returned to normal values after treatment. In contrast, both levels increased in patients who worsened after treatment. Thus changes in Eo and LDH correlated well with the clinical picture. However, IgE levels did not correlate with the clinical condition. High LDH levels were detected in the severe type of AD more frequently than in the mild type. A large majority of patients with elevated LDH (higher than 300 IU/l) before treatment had more severe skin eruptions. When the LDH before treatment was within normal limits, the LDH levels in improved patients showed a further decrease. Eo, LDH and IgE were correlated closely with the clinical scores of AD, and the relationship between LDH and clinical score was the highest. Elevations of LDH5 and LDH4 among the LDH isoenzymes were more prominent in the severe type of AD than in the mild type. We concluded that LDH was useful as a marker for evaluating the disease condition and severity of skin eruption of AD.

Adolescent↗

Poikiloderma-like lesions on the neck in atopic dermatitis: a histopathological study.

Reticulate pigmentation with or without skin atrophy, depigmentation and telangiectasia is frequently encountered on the neck of severe cases of adult type atopic dermatitis. These skin changes were graded clinically into 3 stages. Based on histological features, hyperplasia of the sebaceous gland, dilated tortuous capillaries, and mild degeneration of elastic fibers were noted in stage I lesions. Lesions of both stages II and III contained increased melanin in the basal cell layer with incontinence of pigment, remarkable destruction and degeneration of elastic fibers, proliferated and dilated capillaries, and deposition of mucinous substances. The numbers of mast cells in papillary dermis were significantly increased in late stage I and stage II lesions. Poikiloderma-like lesions on the neck could be attributable to chronic inflammation and delay of wound healing process, possibly caused by long-standing topical corticosteroid therapy.

Adolescent↗

[Treatment of adult type atopic dermatitis (AD) with bacterial vaccine prepared from individual cases (I)--Clinical study].

Bacteria on the skin surface are well known to be one of the precipitating factors of AD. We have treated 68 severe cases of adult type AD with bacterial vaccines prepared for individual cases. Bacteria were collected from lesional skin of each individual and cultured. More than 50% of cases (36/68) showed improvement clearly. Five out of 9 cases without topical steroid showed good response to this treatment. In regard to its clinical response it is suggested that the treatment should be continued for at least 1-2 years, because these cases treated for less than 1 year have high risk of recurrence. Five cases responded excellent showed complete remission of dermatitis for 10 months to 2 years after stopping of this treatment. These results suggest that bacterial vaccine can be beneficial for the treatment of severe cases of adult type AD, which did not respond to other therapy.

Adolescent↗